Introduction: Introducing LoRa™ !

Picture of Introducing LoRa™ !

LoRa™ =Long Range wireless data telemetry and relates to a radical VHF/UHF 2-way wireless spread spectrum data modulation approach that has recently been developed & trademarked (™) by Semtech - a long established (1960) US multinational electronics firm. Refer [1]=>

The technology behind LoRa™ was developed by Cycleo, a French company acquired by Semtech in 2012. LoRa™ is proprietary, but it appears to use some sort of "simpler" CSS (Chirp Spread Spectrum) pulsed FM "sweeping frequency" modulation rather than DSSS (Direct Sequence SS) or FHSS (Frequency Hopping SS).

Semtech's web site mentions that "LoRa™ technology offers a 20dB link budget advantage compared to existing solutions, which significantly extends the range of any application while delivering the lowest current consumption to maximize battery life."

Claimed ranges are typically x10 that of regular UHF wireless data systems. Yes -compared with regular narrow band data setups LoRa™ gives 100s of metres rather than 10s, several 1000m rather than mere 100s. Magic !

LoRa™ is somewhat complicated,as it uses terms and requires settings likely unfamiliar to many "normal" users. Pleasingly however it's been found possible to verify claims with simple setups - here using paired UK sourced US$3 PICAXE micros as the controllers. PICAXEs are near ideal for such trials as they're programmed in high level interpreted BASIC & any execution speed overheads are incidental for the s-l-o-w LORA™ data !Refer [2] =>

Step 1: Semtech's SX127x

Picture of Semtech's SX127x

In recent decades, & aided by cheap PC processing,diverse smart digital modes have been developed (especially by radio hams) for lower frequency HF (3-30MHz) work where bandwidth is precious. (Bandwidth hungry spread spectrum modulation is usually illegal on these lower frequencies). Some modes can span oceans with low power (a few Watts) but are slow & need sophisticated PC software for encoding/decoding, along with very sensitive comms. receivers and significant antenna. Refer [3] =>

Semtech's VHF/UHF SX127x LoRa™ RF ICs however house almost everything within a smart thumb nail sized ~US$4 chip!

Semtech makes several RF IC variations, with the SX1278 being lower UHF frequency slanted to suit 433 MHz ISM band users. Higher freq. 800-900 MHz offerings appeal for more professional work, although at these near 1GHz frequencies reduced RF punch and signal path absorption may be an issue. Sub GHz frequencies however have lower noise, legally higher transmit power & more compact high gain antenna that may offset this.

As well as LoRa™.modulation (shown pictured), SX127x transceiver modules can also produce FSK, GFSK, MSK, GMSK, ASK/OOK and even FM tone signals (Morse Code !) to suit legacy systems. Refer Semtech datasheets (131 pages!) [4] =>

Note: HOPERF, a long established Chinese wireless data firm, offer LoRa™ modules with a "'7 a side" RF96/97/98 IC that seems akin to Semtech's SX127x. It's unknown however if these are just an Asian LoRa™ 2nd sourcing...

Step 2: LoRa™spread Spectrum Benefits !

Picture of LoRa™spread Spectrum Benefits !

SS (Spread Spectrum) systems are not new, but their sophistication meant they were far too costly for many users until modern microelectronic approaches evolved. As SS techniques offer significant interference and fading immunity, security & "undetectable" transmissions they've long the domain of the military - even as far back as WW2. Check the amazing 1940s work of bombshell actress Hedy Lamarr ! [5] =>

LoRa™'s likely Chirp SS modulation, as well as enjoying other SS benefits,may offer Doppler effect "shifting frequency" immunity too - perhaps significant in fast moving LEO (Low Earth Orbital) satellite radio applications. See [6] =>

But -here on earth- most attention arises from claims made by Semtech (& the 2014-2015 promotion of many others -IBM & MicroChip included!), that low UHF spread spectrum LoRa™ devices boost ranges by at least an order of magnitude (x 10) over traditional NBFM (Narrow Band FM) data modules under similar conditions and setups.

Much of this amazing range boost seems to come from LoRa's ability to work BELOW the noise level. The basis of this may relate to noise being random (& hence self cancelling over a period), while a signal is ordered (with multiple samples thus "building it up"). Refer the concept at the attached surf picture !

Although very low powered "smell of an oily electron" mW level transmitters may hence be feasible (& battery powered setups may have a near shelf life of perhaps years), LoRa™'s downside however is that weak signal long range links may be associated with very low data rates (<1kbps). This may be incidental for occasional IoT (Internet of Things) monitoring in applications involving temperatures, meter reading, status & security etc.

Step 3: SIGFOX - Network Based IoT Rival ?

Picture of SIGFOX - Network Based IoT Rival ?

Perhaps LoRa™'s closest IoT long range LPWA (Low Power Wide Area) wireless rival is French company SIGFOX [7] =>

Unlike Semtech's proprietary LoRa™, SigFox's devices are pleasingly open sourced, BUT they demand a specialized linking network. They hence become useless, much as do cell phones, when out of SigFox network coverage - a particularly telling factor in remote regions (or for the many countries not yet served!). Ongoing service charges or surging technical progress may become an issue too - Metricom's late '90s ill-fated 900 MHz "Ricochet" wireless Internet service springs to mind [8] =>

SigFox devices differ from LoRa™ in using UNB (ultra-narrowband) 100Hz radio “channels”, with BPSK (Binary Phase Shift Keying) modulation at 100bps. Transmitters are similar battery friendly 10-25 mW, but in the license free 868-902 MHz bands. Rooftop base stations, which connect to the Internet via fibre etc, have ultra sensitive -142dBm receivers. Ranges of 10’s of km may result (hence similar to LoRa™) - data links have been reported from high flying aircraft and offshore vessels when near SigFox base stations.

But just 12 byte messages, limited to 6 messages per hour, are allowed. Information arrives in a few seconds, but the SigFox network cannot support such real-time communications as credit card authorizations, and the system best suits data “snippets” transmitted a few times a day. Typically these may include remote utility meter reading, flow & level monitoring, asset tracking, emergency alerts or car parking spaces - the latter a real asset!

SigFox networks are quite simple and can be deployed at a fraction of the cost of a traditional cellular system. Spain & France are already covered with ~1000 base stations (vs 15,000 for standard cellular service), with Belgium, Germany, the Netherlands, UK (via Arqiva) and Russia soon to follow. Trials are also underway in San Francisco,

Sigfox doesn't directly build these networks however, but contracts with local companies to handle the relatively simple deployment of rooftop base stations and antennas. . Roll out can be rapid and cost effective- their deployment partner in Spain spent $5 million to deploy a network across the country in just 7 months. These local partners then resell IoT services, at end user charges around ~US$8 a year per device.

Uptake of the SigFox approach has been dramatic, with an early 2015 funding drive raising > US$100 million. Wireless rivals TI/CC (Texas Instruments/ChipCon), who recently joined SigFox, in fact indicate that Lora™ may have weaknesses - see [9] =>

Hands on SigFox investigations have been difficult to locate, but see "Instructable" level insights [10] =>

It could be that both approaches eventually coexist, much as do 2 way radios (= LoRa™) and cell phones (= SigFox) for voice level comms. At present (May 2015) LoRa™ is certainly THE way to explore long range IoT wireless possibilities- read on!

Step 4: Chinese LoRa™ Modules -1

Picture of Chinese LoRa™ Modules -1

Although an EU invention, Semtech's SX127x LoRa™ engines have been very eagerly taken up by Chinese manufacturers. LoRa's ability to punch thru' obstructing buildings in crowded Asian cities has no doubt been been appealing.

Makers in China's mega e-city of Shenzhen (near Hong Kong) have been especially enthusiastic, with offerings noted from such "makers" as Dorji, Appcon, Ulike, Rion/Ron, HopeRF, VoRice, HK CCD, Shenzhen Taida, SF, NiceRF, YHTech & GBan. Although their interface pinouts differ somewhat, the 2 chip "micro moderated" modules fromDorji, Appcon, VoRice & NiceRFseem almost badge engineered.

Extensive Googling is hence recommended for those after bulk purchase, samples, free shipping, more lucid technical insights, better access to SX127x features/pins, easier control, lighter weight, rugged packaging (YTech'sE32-TTL-100 style) etc. Browse the likes of EBay, Alibaba or Aliexpress [11]=>

Step 5: Chinese LoRa™ Modules - 2

Picture of Chinese LoRa™ Modules - 2

Be alert that cheaper (< $US10) single chip modules control the SX1278 via tedious clock linked SPI (Serial Peripheral Interface). Although they're larger & more costly (~US$20), two chip LoRa™ modules use a 2nd on board MCU (microcontroller) for the SX1278 linkage, and are usually much easier to configure & work with on the fly. Most offer friendly industry standard TTL (Transistor Transistor Logic) transparent data handling via simple RXD & TXD pins. Tiny red & blue LEDs are usually fitted onboard the TTL modules - handy for TX/RX insights.

NOTE: 8 pin offerings may use 2mm pin spacing rather than the standard 2.54 mm (1/10th inch), which could limit solderless breadboard evaluation.

Although the near price doubling of TTL LoRa™ devices may be daunting, skinflints could consider cheaper (both to purchase & ship) boards without the SMA socket & matching "rubber ducky" aerial. It'll not be as professional of course, but a simple ¼ wave (~165mm long) whip can readily be made from scrap wire. This may even out perform the "rubber ducky" antenna too-especially if elevated !

Overall (and -sigh- likely rapidly influenced by the increasingly numerous offerings), at the time of writing (mid April 2015) Dorji's433 MHz DRF1278DM seems the easiest way to get started with LoRa™. However this module's limited pinout access,HEX level tweaking & need for higher supply voltages (3.4 -5.5V) may be a limitation.

Step 6: Dorji DRF1278DM

Picture of Dorji DRF1278DM

Chinese maker Shenzhen Dorji sells these micro commanded DRF1278DM modules for ~US$20 each from Tindie [12] =>

The 7 pins are spaced the usual breadboard friendly 2.54 mm ( = 1/10th inch). A supply between 3.4 - 5.5V is needed. The module electronics however work at lower voltages - there's an on board 3.2V voltage regulator. This higher supply need is irksome in todays "3V" era, as although this suits USB 5V (or even bulky 3 x AA 1.5V cells), it prevents use of single 3V Li coin cells etc. The regulator could perhaps be bypassed?

Step 7: DAC02 USB Adapter

Picture of DAC02 USB Adapter

A cheap USB - TTL adapter (here Dorji's DAC02) can be used for module configuration via "RF Tools" PC software. Modules are mechanically rather unsupported when inserted however, and repeated use may stress the pins...

Similar adapters abound at very low prices, BUT pre use it's essential to first ensure pin functions on the adapter match those on the wireless module ! If they don't (with VCC/GND swaps common) then flying lead approaches may have to be used. Although a tad tedious these can also be more versatile as they suit config. of other modules (refer the HC-12 transceiver setup) and even direct terminal program display on a PC.

Step 8: USB Config Tools + SF, BW and CR Insights

Picture of USB Config Tools + SF, BW and CR Insights

Herewith screens typical of the user friendly USB configuring "RF Tools". Dorji modules worked out of the box, but the frequency and power settings should at least be altered for local regulations. Many countries limit 433 MHz transmitter power to 25 mW (~14 dBm) or even 10mW (10dBm) - these are Dorji power settings 5 & 3 respectively.

The licence free ISM band, which covers a ~1.7 MHz slice between 433.050 - 434.790 MHz, does NOT allow transmissions on exactly 433.000 MHz either !

Transparent data handling looks thankfully to occur,meaning whatever serial data is fed in is eventually itransparently dentically fed out after "on air" transmission. However the rumoured 256 byte buffer looked more like 176 bytes (CRC overhead?), some settings with the Dorji tool were difficult to interpret, and changes "written" were not always shown to have been accepted either...

Download Dorji's DRF_Tool_DRF1278D.rar config tool (listed near bottom RHS "Resources" column) via =>
Check diverse insights (especially P. 9 -10) into it's use and USB adapters etc =>

Explanation of LoRa™ spread spectrum terms: (N.B. Data rate relates to BW & SF)

BW (Band Width in kHz): Although mere 10s of kHz BW may appeal, it’s important to appreciate that cheap 32 MHz crystals used by many LoRa™ modules (Dorji & HOPERF etc) may not quite exactly match in frequency. Temperature related drifts and aging may also arise too. Selection of narrower bandwidths may hence prevent module synching unless tedious crystal tweaking & thermal regulation is employed. Although Chinese LoRa™ module makers like Dorji recommend a BW minimum of 125 kHz, for most purposes a narrower BW of 62.5 kHz should be quite OK. Refer shaded table column shown in Step 10.

SF (Spreading Factor “chips” as a base-2 log): In SS systems each bit in the pseudo-random binary sequence is known as a "chip". Incrementing from 7 (2^7 = 128 chip pulses per symbol) up to the limit of 12 improves sensitivity by 3dB each step, but approx. halves the data rate. Although hence a SF of 11 (2^11 = 2048) is 12dB more sensitive than SF7, the data rate drops (at 62.5 kHz BW) from ~2700 bps to just 268 bps. Slow data rate transmitters stay on longer too & thus may also consume more energy overall than transmitters sending faster data.

However very low data rates may be tolerable for occasional IoT (Internet of Things) monitoring of course (& the increased battery energy drain near incidental), while the x 4 range boost could be extremely worthwhile!

CR (error Coding Rate): Initial UK tests used a CR of 4/5. (This denotes that every 4 useful bits are encoded by 5 transmission bits ). Increasing CR to 4/8 lengthens transmit time by ~27%, but improves reception by 1 to 1.5dBm, representing a potential range improvement of some 12 to 18%. This CR tweak probably will not give as beneficial a range gain as incrementing the SF.

Most NZ trials were at 434.000 MHz, 2400 bps serial data, SF7, 62.5kHz BW and CR 4/5.

Step 9: Direct DRF1278DM Configuration.

Picture of Direct DRF1278DM Configuration.

The DRF1278DM can also be configured from an external microcontroller- even a humble 8 pin PICAXE-08. Although involving cryptic base 16 HEX coding, this allows on board/on the fly tweaking rather than continual module removal & USB adapter configuration. Refer full details P.7-8 at the Dorji . pdf. [13] =>

Although it offers diverse sleep features, HEX level tweaking insights may be also gained via Appcon's (near lookalike) APC-340 data sheets [14] =>

Thanks to fellow Kiwi Andrew "Brightspark" HORNBLOW herewith a PICAXE-08M2 code fragment to modulate the DRF1278DM TX power into a staircased ramp of transmission blips. (For easier range/power insights these could readily be associated with receiver end PICAXE generated tones too). Note however that TX levels 6 & 7 exceed the NZ/Australia allowance of 25mW (~14dBm or setting 5). Andrew's insights arose from monitoring / copying and pasting the raw hex serial data fromterminal.exe (a superb engineering tool [15] => ) while viewing the serial data chatter to and from the modules when the RF power level is changed.

The Dorji power level step = 4th byte from the RH end ( $01, $02 etc) plus the following CS byte (CheckSum $AB,$AC etc) just need to be tweaked. Sample PICAXE code sentences to modify the power level on the fly are as follows:

wait 2
 serout 4,T2400,($AF,$AF,$00,$00,$AF,$80,$01,$0C,$02,$00,$6C,$80,$12,$09,$00,$07,$00,$00,$00,$01,$AB,$0D,$0A) 
serout 4,T2400,($AF,$AF,$00,$00,$AF,$80,$01,$0C,$02,$00,$6C,$80,$12,$09,$00,$07,$00,$00,$00,$02,$AC,$0D,$0A) 
serout 4,T2400,($AF,$AF,$00,$00,$AF,$80,$01,$0C,$02,$00,$6C,$80,$12,$09,$00,$07,$00,$00,$00,$03,$AD,$0D,$0A) 
 serout 4,T2400,($AF,$AF,$00,$00,$AF,$80,$01,$0C,$02,$00,$6C,$80,$12,$09,$00,$07,$00,$00,$00,$04,$AE,$0D,$0A) 
serout 4,T2400,($AF,$AF,$00,$00,$AF,$80,$01,$0C,$02,$00,$6C,$80,$12,$09,$00,$07,$00,$00,$00,$05,$AF,$0D,$0A)
 serout 4,T2400,($AF,$AF,$00,$00,$AF,$80,$01,$0C,$02,$00,$6C,$80,$12,$09,$00,$07,$00,$00,$00,$06,$B0,$0D,$0A)
 serout 4,T2400,($AF,$AF,$00,$00,$AF,$80,$01,$0C,$02,$00,$6C,$80,$12,$09,$00,$07,$00,$00,$00,$07,$B1,$0D,$0A) 
 wait 2

Step 10: Performance Estimations & Results !

Picture of Performance Estimations & Results !

PICAXE 28X2 driven HOPERF 434 MHz Semtech LoRa™ based RFM98 data modules were used in trials conducted over a 750m link in a typical UK urban environment. The transmitter antenna was elevated ~2½ m on a low mast, with the receiver on a short pole ~1½ m – both above ground. With a confirmed 750m dense urban environment range at UK’s 10mW TX (using 500kHz BW & thus giving ~22kbps), then at 10.4kHz BW (or 455 bps) some 6 km look feasible with sub mW power !

Confirming field tests (with settings SF7 & only BW 62.5 kHz) were made in Wellington (NZ) with 3 x AA battery powered PICAXE-08M driven Dorji DRF1278DM modules & similar antenna, but at Aus/NZ’s "paint blistering" higher 25mW (14dBm) TX power. Suburban signal links, perhaps aided by a more open environment and wooden buildings, were consistently made over 3 - 10 km. (As 6dB gain doubles LoS range, then 4dB extra power ~x 1½. & hence ranges may improve over implied UK ones by >1½ times).

Step 11: Breadboard Layout

Picture of Breadboard Layout

A breadboarded layout (used previously for Dorji's "7020" GFSK modules) suits simple swap over to the LoRa device. GFSK (Gaussian Freq. Shift Keying) modulation has previously been considered the best 433 MHz approach, so it was beneficial to compare results of the "7020" offerings with the new LoRa modules.

Step 12: PICAXE Schematic

Picture of PICAXE Schematic

Both the RX & TX use a near identical layout, although their code somewhat differs. Although naturally appealing and readily achieved with PICAXEs, no attempt was made at this stage to enter energy saving sleep modes. Current draw from 3 xAA batteries was ~15mA, pulsing to ~50mA when transmitting.

Step 13: PICAXE Transmitter Code

Picture of PICAXE Transmitter Code

Naturally this code can be extensively enhanced and modified, perhaps with settling delays and preambles. Presently it's essentially just spitting out an advancing 0-100 number. As the trial was merely intended to verify reliable range claims, no attempt was made (with either transmitter or receiver) to enable power saving modes.

Step 14: PICAXE Receiver Code & Display

Picture of PICAXE Receiver Code & Display

Here's the associated PICAXE receiver code, with numeric values displayed via the editor's inbuilt "F8" terminal. The beauty of a simple count is that sequences can quickly be visually scanned & missing or swampy values readily spotted.

Step 15: User Friendly LoRa™RF Tuneup Aids?

Picture of  User Friendly LoRa™RF Tuneup Aids?

As LoRa™ module settings can be difficult to comprehend and verify, it's pleasingly been found possible to use cheap (& relatively broadband) ASK 433 MHz receiver modules as simple tune up aids.

NZ/Aus outlet Jaycar offer a ZW3102 module that can readily be persuaded into "sniffer duties" to suit audible signal monitoring. When near (< 5 metres) to LoRa™ transmissions the outgoing signal will readily be heard as "scratches",while the brightness of an attached LED relates to RSSI (Received Signal Strength Indication).

A similar (& cheaper) module made by Dorji is featured in Instructable [16] =>

Step 16: Field Tests- Wellington, New Zealand

Picture of Field Tests- Wellington, New Zealand

This beach setup shows the earlier testing with Dorji's "7020" GFSK (Gaussian Frequency Shift Keying) modules. Ranges then maxed at ~1km in such conditions, and at best were ~300m thru' light vegetation & the localities wooden framed buildings. Cross harbour links were only found possible when the transmitter was significantly elevated some 100m up at an eagle's nest view spot on a hillside behind.

In contrast Dorji's LoRa modules at the same 25mW power "flooded" the suburb, with arm high (~2.4m) transmissions reliably detected to ~3km close in, 6km at headland "sweet spots" and even 10km surface LOS across harbour. Reception only ceased when in bays behind the rocky headlands (visible in the background). LoRa settings were, BW 62.5kHz, SR 7, CR 4/5 and 25mW (14dBm) TX power into a ¼ wave omnidirectional vertical antenna.

Step 17: UK LoRa Versus FSK - 40km LoS (Line of Sight) Test !

Picture of UK LoRa Versus FSK  - 40km LoS (Line of Sight) Test !

Thanks to Cardiff based Stuart Robinson (radio ham GW7HPW), FSK (Frequency shift keying) versus LoRa™ comparison tests were carried out over an elevated 40km distance across the UK's Bristol Channel. Refer picture.

The region is rather wireless historic as in 1897 Marconi carried out his first "long range" (6 - 9km using power hungry spark transmitters!) tests nearby [17] =>

Stuart's results speak for themselves - LoRa™ data links were amazingly possible in 2014 at a fraction of the power needed for his previously well respected Hope RFM22BFSK modules!

A PICAXE-40X2 controlled RFM22B in fact is still up orbiting in the esteemed $50sat, with weak ground signals detectable as it passes in LEO (Low Earth Orbital) many 100s of km above. ( LoRa™ modules were not available at it's 2013 launch time ) [18] =>


Step 18: Other Region Tests

Picture of Other Region Tests

Successful links were made over 22km LoS (Line of Sight) in Spain & several km in urban Hungary.

Check the Libelium promotion that shows the technology's ~900MHz benefits[19] =>

Step 19: LoRa Receiver & Links

Picture of LoRa Receiver & Links

UK HAB (High Altitude Ballooning) trials gave 2 way LoRa™ coverage at up to 240 km. Lowering the data rate from 1000bps to 100bps should allow coverage all the way to the radio horizon, which is perhaps 600 km at the typical 6000-8000m soaring altitude of these balloons. Balloon tracking can be made via ther on board GPS - check the extensive HAB & LoRa™ documentation at [20] =>

A LoRa receiver for both HAB & future LEO satellite work is under development - details to follow.

Summary: LoRa™ is shaping up as disruptive technology, especially for emerging - and much hyped- IoT (Internet of Things) wireless networked applications. Stay informed via the LoRa Alliance site [21] =>

Disclaimer & appreciation: This account is essentially intended as a heads up/hands on investigation & compilation of -what seems- a game changing UHF wireless data technology. Although welcoming free samples (!), I have no commercial links with any of the LoRa™ makers mentioned. Feel free to "copy left" this material - especially for educational use- but site credit naturally appreciated.

Note: Some images have been web sourced, for which (if not referenced) appreciative credit is hereby extended.

Stan. SWAN => Wellington, New Zealand. (ZL2APS -since 1967).

Links: (As at 15th May 2015)























manuka made it! (author)2015-09-12

Some kind soul has removed the RN2483 cover to reveal the internals. Note the RN2483 is conveniently serial addressed rather than more tedious SPI. It also includes an inbuilt RTC (Real Time Clock) which could be handy for energy saving system wakeups. These RN2483 are now available from Mouser in the US $15 range =>

andrewtaneglen (author)2017-12-07

Hey Manuka! I've been looking into using Lora for a local conservation group to monitor their Stoat traps. The traps are on a roughly 100 metre spaced grid over steep terrain, and there are hundreds of them.

I was initially going to try wifi, but became concerned with the range. Reliable wifi through 100m of bush doesn't seem feasible. Does this seem correct?

So lora seems the way forward, with something like the E32-TTL-100S1. Do you know of anything better?

Do you have any recommendations on using lora in a mesh? The placing of the traps seems ideally suited to this. Each trap will reliably communicate with each adjacent trap, but the terrain means all traps won't reliably communicate with all other traps.

Thanks for the instructable. It's a great place to start on this stuff, which is exactly where I am!.



manuka made it! (author)andrewtaneglen2017-12-07

Hi Andrew ! Quick initial comments = where are you (& this trapping site)? What sort of traps used? How often checked anyway? Budget? Time frame? Your e-skills? Have you made any quick wireless trials (using say UHF CB handhelds)? How circuitry likley to be powered ? Overhead vegetation not so dense that solar powering ruled out?

WiFi indeed would be near useless, BUT 433 MHz could suit. Cheap (US$5 range) high performance 433 MHz modules now abound, with the Chinese HC-12 transceiver (as below) particularly well thought of.

If you've just 100 metres range then LoRa is probably an overkill, especially since it's more costly & still developing (VERY rapidly !) => and especially =>

Stan.- Wellington, NZ

manuka (author)manuka2017-12-10

Andrew: OK & thanks for full briefing, which increasingly seems familiar in fact ! About a year back a VERY similar request came in from an Andrew who was also trapping up your way - although I recall then it was possums & over a wider catchment! Was this you ?

Irrespective the next step is to make a simple UHF penetration check. Cheap handheld UHF CBs are ideal for this, as if their 1/2 Watt voice signal can't penetrate the bush then certainly a 25 mW data signal will be struggling. Best supply me a Google Earth link too so I can visualise the region.

I await your report ! Regards- Stan. ( Wellington )

andrewtaneglen (author)manuka2017-12-13

Hi Stan,

Thanks for the reply.

That must be another Andrew, but sounds like someone I'll probably bump into before too long.

Handhelb UHF CBs sound like a great Christmas present for my boys, I'll pick some up this week and have a go.

I'll let you know what I find.

I thought I'd put a map link in the last email, but here's another one:,174.5563647,4452m/data=!3m1!1e3


andrewtaneglen (author)manuka2017-12-09

Hi Stan,

Thanks for your reply. I'm up near Whangarei. The trapping area is Bream Head, at the end of the Whangarei Heads. (

The traps are standard DOC traps (DOC 150, 200, 250 etc), so totally manual. They're checked on a roughly two week schedule by a team of volunteers.

The head ranger is a mate of mine and reckons, at the rate they catch stoats these days, one person could manage all the traps if they knew which ones had animals in them. This is what got me interested in finding some way to automate the monitoring process.

I'm an electrical engineer and work primarily in embedded programming for marine electronics. So I've done lots of bare-metal stuff and also a fair amount in embedded linux.

In terms of budget, there is none, other than my own keenness to spend what ever is required to find out what's possible. Looking at what's available I reckon $40-50 per-trap would be feasible with a rasberry pi + radio + solar/battery + enclosure.

There is no time frame. I'm doing this off my own bat as it would be great to apply some electronics to something close to home. And it would be great to find a technological alternative to 1080 drops.

I haven't made any radio tests yet. I'm still in the conceptual stage, or more accurately the 'too many options' paralysis stage.

It will have to be powered by solar/battery. Lora sounded more attractive primarily for the lower power requirement for the same range. Powering devices indefinitely will be the key issue in getting this all to work, so I'm basically looking for the lowest powered digital radio link through 100m of bush. I think a net loss of charge would be fine, if the battery still lasted months in the worst-case shady areas.

The other key issue will be managing a basically open ended mesh of devices, but at this stage I'm just investigating which physical/radio layer to start with (do you still say 'physical layer' with radio?).

Thanks again for your message.


JaimeZ14 (author)2017-12-11

manuka - have you had any experience configuring one device as a transceiver? I am also wondering if you have tried to detect two transmitters at once?

I am hoping to make a simple game where three people are racing to find each other with these.

moebius.lutching (author)2017-07-20

Thanks for the article! I just decided use LoRa on my next project... I pick a pair of the Whisper Node LoRa (, as apparently they are designed to run on Battery and that's exactly what I'm after.

manuka (author)2017-03-11

Scios: OK on your "8000 hectare" cattle farming cousin, & glad he's looking at commercial options ! You never did specify either his "farm's location " or it's terrain- such apscts are CRUCIAL for comms. insights...

At your UHF starter level perhaps the best INITIAL way is with some simple handheld UHF PRS CBs used to explore coverage. Their power is typically a few Watts, giving a range maybe a few km in built areas, but MUCH more if Line of Sight (LoS).

LoRa offers 10 times the range for the same power, BUT you are legally only allowed 25milliWatts ! As every 6dB gain doubles range (thus 100mW gives twice the range of 25 mW) then by chance 25 mW LoRa will cover about the same as 1 Watt PRS.

As fair as UHF data starters go, these days I suggest the extremely versatile US$5 Chinese HC-12 transceiver modules. I import these directly from Satisfy Electronics in China (freight free too), & all my work with them has been PICAXE related (& GUI config).

HC-12 now have significant Arduino/Instructable exposure, so suggest checking the likes of this =>

Regards- Stan.

Scois (author)manuka2017-03-12

Thanks for all your advice and help, Stan. Will check out your suggestions.


manuka (author)2017-03-07

Kiwi firm Gallagher's approach is essentially water TANK level monitoring, which is probably less prone to stock mischief.& vegetation etc than open ponds/dams. A quick Google shows an Australian firm seemingly offering similar, with the 2 way radio gear off the shelf UHF CB PRS handhelds! See =>

But you can't beat "management by walking around" on a farm! There may be the likes of sick/dead cattle polluting the pond that a sensor would not register. Here in NZ some farmers are already using agricultural drones to check crops, stock, gates & dams etc - ranges of the on board video camera can be several km ! See a recent ag. drone review => Stan.

Scois (author)manuka2017-03-09

Stan, I have to get a few google pointers from you. Don't know how you found Electrosense. They have a very interesting product.

Do you have a few ideas on what to search for regarding UHF CB PRS and how to use them with an Arduino? I don't know if searching using "UHF CB PRS Arduino" is returning the correct results.

The use of drones are amazing. I can see how they can safe a lot of time and money.

manuka (author)Scois2017-03-10

Scios: Mate- Google may well be our friend but years of browsing experience can refine ! Aside from this I fincreasingly feel that almost no UHF radio link may be up to your cousins monitoring challenge.

His 8000 hectares spread is "equivalent" to a rectangle of sides 40 km x 20km for heavens sake. Aside from the terrain (which you STILL have not clarified) the curvature of the earth may well come into play for UHF signals propagated from near the ground. And being water holes they probably WILL be at ground level ( or even below) - your cousin may need to erect significant TALL masts to raise the trasmitters high enough for coverage.

To put terrain in pespective consider my harbour side Wellington location. In FRONT we've a clear view across water & can see NZ's South Island ~40km away across Cook Strait, but immediately BEHIND me are a range of thick bush clad hills that rise to 1000 metres. Even a 5 Watt PRS handheld is pushing to get a km in the latter.

All up - & since his spread is obviously a commercial business- tell him to take a look at drone planes that can fly a programmed waterhole circuit & take pix for him to view. Copters have too short a flight time (approx 10min) but planes of course have wing lift & some FPV (First Person View) ones can stay up for MUCH longer.


Scois (author)manuka2017-03-11

Thanks Stan,

My cousin has contacted Electrosense and they are going to see if they can help him.

From a personal view I am still really interested in playing around with Arduino and UHF. Can you give me a few pointers on what to search for?


manuka (author)2017-03-05

Scois: MATE - an 8000 acres "farm" & 20 km links ( LoS ?) , along with seemingly a mission critical stock watering need ! We are NOT talking hobby farm/kids stuff here, & I suspect the application is also VERY commercial.

Thought for the future - specify the setup RIGHT at the beginning of a technical request so helpers can better get an handle on things.

At least in outback Queensland you should have plenty of sun for solar charging, but the implications of something falling over are pretty profound... I was raised on a NZ farm & well know how even simple things (stock hi jinks etc) can cause mischief...

25 mW LoRa at 433 MHz may just do but I'd say that UHF CB "PRS" channels 21 & 22 are best suited. These legally allow 5 Watts TX power & are specifically assigned for just such telemetry & telecommand applications. Regards- Stan.

Scois (author)manuka2017-03-05

Thanks Stan, never say never. At this stage I just want to try and give him something that will make his life a bit easier. Will see what eventuates.

My initial aim was to get some more understanding regarding LoRa. There are not a lot of sites that is 100% LoRa. And rather explaining the concept they would just include a link to your site. It appears as this instructable have become the definitive LoRa site.

I will have a look at the 2 options you mentioned. But I will definitely follow your advice and play around with the HC-12's. I had a look at a few sites and they appear to be very interesting. One question though - Is the spiral antenna good enough or should I invest in a cable and rubber ducky?


manuka (author)Scois2017-03-05

Scios: That HC-12 spiral antenna is no great shakes, but then many rubber duckies aren't either! Further more feedline losses can be quite significant & may even cost you performance.

At UHF far & away it's best to ELEVATE the setup & try to get as near LoS (Line of Sight) as possible. HC-12 are good performers but you'll only get perhaps a few hundred metres reliable range thru' typical urban clutter (wooden buildings, light vegetation).

In the same situation LoRa gives several km - my best performance has been about 15km TRUE LoS cross harbour from elevated sites.
I'd offer to loan your some modules, but return Trans Tasman p&p could be more that they're worth !

Given such a traditional & critical "how's the water level" need I'd STRONGLY recommend you explore commercial offerings. Sure - they may be costly BUT they'll be reliable & also give you DIY ideas. Here in NZ Gallagher's offerings may give you some insights =>

The high power PRS data channels 22 & 23 specifically reserved for just such applications may well have off the shelf offerings. I assume cellular coverage is lacking on this station ? It would again GREATLY help if you specified EXACTLY where it is so the likes of a Google Earth look see can be made. Regards - Stan. (10km LoS cross harbour from Wellington city) =>,174.8896631,18329m/data=!3m1!1e3

Scois (author)manuka2017-03-06

Darn, the Kiwi's beat me to it. I'll pass Gallagher's details and the Wireless Water
Level Monitoring system on to my cousin.

I am still going to try and build something similar. The challenge is on!

Thanks for offering t lend me some of your modules. As you mentioned, p&p. I'm waiting on a few HC-12's to learn RF communication as you mentioned and will have a look at the E-32-TTL-100s1 modules. Am definitely going to look into PRS as well.

Thanks for your help and ill let you know how it goes.


manuka made it! (author)2017-03-01

Scois: I remain a keen LoRa man, but confess to not progressing on
from Dorji's TTL friendly " two chip" DRF1278DM. The SPI "single chippers" of HopeRFare certainly smaller & cheaper, but their software can be much more demanding.

In fact some Chengdu EByte E-32-TTL-100s1 Chinese
modules just to hand may be tempting, especially since they are US$6-$9 each. I've yet to give them a whirl, but you may stimulate me into doing so ! See =>

Regards- Stan

Scois (author)manuka2017-03-03


I know what you mean by the software of the SPI "single chippers" can be demanding. There is just such a big price difference between the TTL friendly "two chip" and the SPI "single chippers". So far I have been a sucker for punishment and couldn't convince myself to got for the more expensive versions.

I've got a few DRF1278F's and Semtech's inAir4 that I am fighting with at the moment. Trying to understand native code first before using libraries. I think I understand SPI now, just have to get into the SX1278 commands. You will probably hear me in Wellington when I get them to work.

I will have a look at the 'Chengdu EByte E-32-TTL-100s1'. There range seems a bit on the low side? I have come across modules that claim up to 15km LOS.

What do you think about this module -

How do you decide what is a good Lora module. I mainly look at range. Is there anything else I should be looking at?


manuka (author)Scois2017-03-04

Scios: Ahem- although that board at is billed as "LoRa" I seriously doubt it! Semtech LoRa products are 7 pins aside & labelled Semtech/SX or HopeRf (2nd sourced). That " 8 a side" chip looks an STM micro. The sockets imply some sort of stacking is needed for yet another board - which is probably actually an SPI LoRa module...

Range is appealing BUT so is reliability & good data rates. Again I say you REALLY need to start simply (perhaps with HC-12) & gain 433 MHz experiences. Folks can waste SO MUCH TIME & MONEY otherwise

I also again point out that NZ/Aus 433 MHz regs allow ONLY 25 mW (milliWatts) transmitter power.


Scois (author)manuka2017-03-04

I've got a few HC-12's on order and start with them once they arrive.

My objective: My cousin is a cattle farmer, on a 8000 hectare property in outback Queensland. Every few days he has to spend hours (and 10's of km's) driving between the various water points, checking water levels. A few sensors and a RF network will save him a lot of time and money.

I am looking at something similar to Dr. Acula's "Simple Arduino Wireless Mesh" network. My biggest obstacle is distance. There is 20km distance between the furthest drinking point and the homestead.

I want to keep is as simple as possible. I.e Sensor(s) --> RF network --> "base" station (LCD display with alarm). My biggest challenge is the RF (distance) network.


Scois (author)2017-02-27


At the time of writing this article, you seemed quite fond of the Dorji DRF1278DM module. Is this still the case? Later on you mention HopeRF as well?

I am playing around with a Modtronix SX1278 module. I uses SPI connections which I found a bit complicated. I hope something like the Dorji, with its TTL connection will make my life a bit easier.

srnet (author)2015-04-23

There is PICAXE, MicroMiteII and Arduino code for SPI LoRa modules such as the DRF1278F and RFM98 to be found here;

The PICAXE code is a complete program for a High Altitude Balloon tracker with two way command and control. The Trackers GPS location is sent and received as LoRa data and FSK RTTY.

There are Eagle files for a simple RFM98 Shield as well.

Stuart Robinson


GabrielS119 (author)srnet2016-03-03

Link is dead smet, can you repost? Also do you have something for the DRF1278DM the pinouts are different and I can't seem to change them on the arduino libraries...

srnet (author)GabrielS1192016-03-03

Trying to get the link changed, it did expire because of some issue on Dropbox a while back.

I don't have any code for the DRF1278DM, its a completely different hardware interface to the DRF1278F and RFM98 that my code was for.

Hans JákupD (author)srnet2016-12-17

did you manage to get the link changed?
i'm looking for code and/or cad files for DRF1278F

srnet (author)Hans JákupD2016-12-18

No, it was not possible to change the link.

If you look on my website on the links page, there is a link to a dropbox with code and other stuff;

Note that there is no code for the DRF1278F specifically, both that and the Hope RFM98 modules use the Semtech SX127x LoRa devices, so the code is written for that IC.

GabrielS119 (author)srnet2016-03-08

Ok thanks anyways.

manuka (author)2016-11-19

Thanks for the link =>

The 2014 era Instructable, although PICAXE related, was intended .(at that time). to outline/verify (in a cost effective manner) Lora issues, settings & claims

FellaMegaOld. (author)2016-09-26

That is A B or C grade silicon.

Intel A , Amd A/B , Via C Processors for example

FellaMegaOld. (author)2016-09-26

The hopeRF modules are semtech factory seconds, they didn't meet the A grade standard.

David_Dragino (author)2016-07-03

I made a new instructable about "How to get sensor data from a remote Arduino via Wireless Lora Protocol"

David_Dragino (author)2016-06-07
GabrielS119 (author)2016-03-03

While trying to configure DRF1278DM with the USB adapter I can't even open the programm it just ends with this error:

""Error reading suiNumberEdit_RfFrequency-> Text: '434:000' is not a valid floating point value!"

Does anyone know why this happens?

manuka (author)2015-11-05

November 2015 update: LoRa™ is rapidly gaining legs, and gateways using LoRaWAN™ are being rolled out.

Check news of one in Australia =>

Here's another in India =>

Here in NZ an inner Wellington firm is doing great stuff with a LoRaWAN™ gateway at 868MHz. (This NZ legal frequency also allows higher power). See => and

michanz (author)manuka2015-12-10

Hi, why do you think that the for LoRa required range of 863 - 870 MHz is legal ? It only would be compliant if there is no use above 868. The band 868 - 870 MHz has a restriction of -27dBW. It is not possible to restrict the use of LoRa below 868 MHz. This would not be in accordance to the existing LoRa standards.

The same applies for European equipment for wireless M-Bus. A compliance request to RSM regarding 868 was rejected. The -27dBW (2mW) does not allow a decent operation for a wireless network.

The conclusion for me is that the 863-870 MHz band can't be used in NZ. Same allies for AUS.

Regards Michael

manuka (author)michanz2015-12-11

Michael: NZ/US/EU/AUS indeed have differing, changing (RSM have just tweaked NZ's!) & perhaps confusing 800-900 MHz ISM spectrum spots & power allowances. That quoted -27dBW is only a puny 2mW - I recall 27 dBm (which = a beefy 500mW of course) is allowed somewhere sub 1 GHz!?

In any case all my LoRa™ work has been done on the 433 MHz ISM spectrum slice, at NZ/ 25mW (=14 dBm = -16 dBW) transmitters.

As it looks as if you are also in NZ, check the work of Wellington IoT firm running LoRa™ on~868 MHz (?) at what's thought to be 500mW TX => and

Regards- Stan.

manuka made it! (author)2015-12-10

Dec 2015: LoRa™ uptake continues-

Schneider Electrical=>

Volcano monitoring =>

manuka (author)2015-12-05

Swiss based MiroMico has helped develop a SX1272 LoRa™ based TBS (Team Black Sheep) Crossfire R/C model long range control system. See =>

Performance has been astounding - using 800-900 MHz links TBS flew out to 20 km distance using only 10mW transmitter power, while at (legally higher) 1.2W power 100km has been reached!

manuka (author)2015-11-02

Glad you found it helpful! My Instructable dates from mid 2014 when I was getting to know it myself,& I'd maybe now take a slightly different slant & focus on HopeRF rather than Dorji etc.

My intention however was to show Lora™ is quite easy to explore AND it indeed measures up to the hype with astounding performance! Here in NZ an inner Wellington firm is doing great stuff with a LoRaWAN™ gateway at 868MHz. See => and

electronut (author)2015-11-01

Thank you for writing this up. Information on LoRa is still hard to comprehed, with all the available options.

sandywulala (author)2015-08-25

I would like to know if LoRa protocol is based on IEEE 802.11 or IEEE802.15 or other protocols? In addition, what is LoRa's power saving solution?

Many thanks for help!

manuka (author)sandywulala2015-08-25

Sandywulala: As Lora™ is their baby you'd really have to ask Semtech about this! Don't forget that Google is your friend too  ...

Those IEEE standards you mention are of course WiFi & Bluetooth at 2.4GHz & intended for nearby & "rapid" data comms.  LoRa™ modulation  is used at much lower freqs, usually around 434 & 868 MHz, & is best suited for S-L-O-W data exchange but over large distances ( km - 10s of km) using very lower power transmitters & super sensitive receivers.

Regards- Stan.

manuka (author)2015-08-23

Zootalaws: It is indeed buried at Dorji's site! The config tool is listed (near bottom RHS "Resources" column) as DRF_Tool_DRF1278D.rar ) at this link =>

Maybe also check the diverse insights (especially P. 9 -10) into it's use and USB adapters etc .

FWIW we found direct config., although a tad tedious, had appeal as tweaks could be done on the fly via ones software. Under PICAXE control (in our case) we usefully stepped the output power as an aid to location distance of the transmitter.

Hope these help ! Stan.

zootalaws (author)2015-08-22

I recently received my LoRa modules from Dorji (DRF1278DM), but cannot find the application you referred to that allows configuration.

Can you post a link?

manuka (author)2015-07-27

Another Appcon based LoRa™ Instructable has also just popped up - see =>

manuka (author)2015-07-07

Microchip's versatile RN2483 EU compilant 434/868MHz LoRa™ module (US$10-$15) is now in production. Their 10/10 claims (being a 10 mile surburban range & 10 year battery life) may well be justified ! See



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Bio: Retired educator/writer
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