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In country like India most of the people are dependent on agriculture.For effective planning in agriculture weather forecast is of utmost importance.So farmers are always interested in the Weather Forecasts.As farmers stay in remote areas, they have to wait for the news updates in TV, Radio or News Papers.Unfortunately this weather information is not the accurate data of their local environment rather it gives data of nearest weather forecasting station.
Being a son of a farmer, I decided to monitor the local weather and inform to my father earlier.So that he can take early decision for his farm.

My weather stations typically consist of two major parts:

1. The sensors that sit outside and measure temperature,humidity, rainfall, and barometric pressure.This data is send wirelessly through a RF transmitter module to the display unit.I named the entire module as Transmitter module.(Tx).

2. The display unit that lives inside in a convenient place so any one can read the external temperature,humidity etc. It equipped with a RF receiver to receive data from transmitter module.I named it as Receiver module (Rx).

Both the module are run by the arduino micro controllers.

As the transmitter module is deployed in the field,we have to deal with the power management.It is impractical to run a long cable to provide power to the sensor’s location.This leaves relatively few practical options.

1. Connecting directly an Arduino board to a battery. Though it sounds good and obviously it would work, but your battery would be depleted in a matter of days because some components like voltage regulators,power led and USB interfacing chip in the arduino board are always drawing power.
But now a days high capacity battery packs are readily available in the market.Solar panels are getting more efficient and cheaper. Adding a boost converter in the circuits extract every last drops of juice out of battery.

2. Putting the arduino to “sleep mode" to consume even less power.

You can see it in the step-11 and 12.


In this guide I will teach a new skills on how you can make a solar powered battery pack for your arduino and how arduino power consumption can be optimize by putting it in to sleep mode.

By using the above technique you can run your sensor related or any other stand alone arduino project for a long time.

Step 1: PARTS AND TOOLS REQUIRED :

PARTS :

1.Arduino Uno (Amazon / eBay)


2.Arduino Nano ( Amazon / eBay)


3. DHT11 (Amazon / eBay)


4.RF transmitter-Receiver pair (Amazon / eBay)


5.20x4 LCD display (Amazon / eBay)


6.LCD I2C module (Amazon / eBay)


7. 3.7 V Li Ion Battery /2 AA Ni Mh rechargable Battery (Amazon / eBay)


8.Boost Converter (Amazon / eBay)


9.Li Ion Battery charging board (Amazon / eBay)


10. Battery Holder (Amazon / eBay)


11.Solar Panel (Amazon / eBay)


12.Resistor 10K ( Amazon )

13.Diode -IN4007 ( Amazon )

14.Jumper wires/Wires ( Amazon )

15.Bread Board ( Amazon )

16.22 AWG solid core wire ( for making antenna) ( Amazon )

17.Scotch mounting pad and tap ( Amazon )

TOOLS :

1.Soldering Iron and solder ( Amazon )

2.Glue gun ( Amazon )

3.Hobby Knife ( Amazon )

4.Drill ( Amazon )

5.Wire cutter/Stripper ( Amazon )

Step 2: SOLAR POWER

Why Solar Power ?

The main draw back of battery operated device is that it will depleted after a certain time.This draw back can be eliminated by using a natural resources like solar,wind or hydro energy.The most obvious free source of energy to recharge the battery is solar energy. It is a relatively simple, cheap and requires very less skill .

Among the rechargeable battery nickle metal hydride (NiMH) and Li Ion battery are widely used for battery operated device.

Facts on Battery Charging :

The thumb rule for charging Ni Mh batteries is 1/10th (commonly known as C/10). To charge the battery pack at 1/10th its rated current requires 16 hours of charge time( You can see the picture).The solar panel receives optimal sunlight for only four hours per day, from 10 a.m. to 2 p.m. Thus, a totally ideal system would require four days to fully charge the battery pack.

What is C/10 ?

For example we have a 2xAA–sized 1300mAh battery pack that is rated at 1.2 volts per cell. With cells in series, our pack outputs 2.4 volts and 1300mAh.

Here capacity C =1300mAh

C/10 means 1300/10 =130mAh

So to charge the above battery pack we need a higher voltage ( 2.4 to 3 V) with a maximum current of 130mAh.

As per C/10 rule it requires 16 hours to fully charge the battery pack.

You must be ask,what will happen if we increase the current (>130mAh) ?No doubt your battery will charge faster.But the life of the battery will be reduce.So my advice is to keep the current bellow the C/10 value.

Step 3: How to Choose the Right Solar Panel

The main source for powering the sensor module is solar panel.So it must be able to provide current for powering the arduino as well as current to charge the battery pack during the day.As per my experience it is the most challenging part for a novice user.

Don't worry these are the following tricks which can help you to buy a right solar panel.

1. Voltage : Choose 1.5 times the battery pack voltage

2.Current : Current taken by the Arduino + current for charging (should be

Example :

A battery pack is made of 2 AA Ni Mh battery.

Battery voltage = 1.2 x 2= 2.4V

So required voltage for solar panel =2.4 x 1.5 = 3.6V

By taking some margin we can choose a 4V solar panel for it.

The sensor module along with arduino taking 100mAh current.

Battery capacity is 1300mAh

C/10 = 130mAh

Solar panel have to provide current 100mAh for arduino along with a current not more than 130mAh.

Lets take 100 mAh for charging the battery
Total current required = 100+100=200mAh

From the above calculation it is clear that we need a solar panel of 4V and 200mAh.


The following table shows the solar system configuration relationship between storage batteries and mini solar panels.

Battery ---->Solar Panel

1.2V ------> 2V ~ 2.5V

2.4V ------> 3.5V ~ 4V

3.6V ------> 5V ~ 6V

6V ------> 7.5V ~ 9V

12V ------>15V ~ 18V

Note : It is not the strict rule for choosing the exact rating solar panel,rather it is approximate rating .I write as per my experience.

Step 4: Ni Mh Battery Charger :

To power a arduino we need 5v.There are two options

1. Use a 4 AA battery pack :

Total voltage =1.2V x4=4.8V (nominal ) but when it is fully charge,voltage is more than 5V.
This is not efficient.


2.Use 2 AA battery pack :

Total voltage =1.2Vx2 =2.4 V

In this case we have to raise the voltage level to 5V by using a voltage booster circuit.

I recommend to use this pack.It is reliable and efficient.
Charging Circuit :

Standard sized nickle metal hydride (NiMH) cells need simple charge circuit.

You only need a solar panel, diode, the batteries, and a battery case and wires.

4 AA battery pack

Solder the positive terminal of the solar panel to the positive terminal of diode.

Solder the negative terminal of diode to the positive terminal of battery pack.

solder the negative terminal of the solar panel to the negative terminal of the battery pack.

See the above picture for soldering.

2 AA battery pack

As the battery pack voltage is not sufficient in this case, we have to use a booster circuit to make 5V for arduino.

Step 5: Boost Converter

A boost converter is a DC-to-DC power converter (like a step up transformer in AC) with an output voltage greater than its input voltage.

Boost converter used in this project have following specification :

>>Input voltage: 0.9V-5V DC

>>Transfer efficiency:96%(max)

>>With USB port

>>With working indicator light

>>with one AA battery power supply output current can up to 200~300mA,

>>two AA batteries to the output current of 500~600mA

You can buy it from eBay

Adafruit have also designed a boost converter known as Minityboost for USB charging.You can also use it.

In our case the input to the boost converter is 2.4V and out put is 5V which is sufficient to power a arduino.

Solder the '+' terminal of boost converter to the battery positive terminal.

Solder the '-' terminal of the boost converter to the battery negative terminal.

Step 6: Li Ion Battery Charger

Among the all charger what I have discussed earlier ,I like it most.This is the most powerful and efficient battery pack.The interesting thing is that you can use this for charging any usb powered gadget like smart phone,tablet,MP3 etc.

If you look at the Periodic Table, you will find that Lithium is on the far left in the first column, where all the most reactive elements live.

Caution :

You must take certain precautions when dealing with Lithium Ion Batteries. In order to maintain a very precise voltage when charging. The 3.7V batteries we're using in this guide need to have a charging voltage of 4.2V.A volt high or a volt low can mean an out of control chemical reaction which can lead to danger.

Don't worry a suitable Li Ion battery charge controller will solve the above problem.

Lithium Battery Charging Board used in this project have following specification :

>> Current- 1A adjustable.

>> Charge precision- 1.5%.

>> Input voltage- 4.5V-5.5V.

>> Full charge voltage- 4.2V.

>> Led indicator- red is charging blue is full charged.

>>Input interface- mini USB.

>> Work temperature- -10℃ to +85℃.

You can buy it from eBay

Circuit Connection :

Solder the Input positive terminal of boost converter(red wire) and battery holder positive terminal(red wire) to the charging board's BAT + .

Solder the Input negative terminal of boost converter(black wire) and battery holder negative terminal(black wire) to the charging board's BAT-.

The boost converter output is a USB terminal. For powering a bread board circuit we need two wires for connection.So we have to modify something according our requirement.

The usb have four terminals (5V,D-,D+and GND).

Solder the red and black wire to the + and - respectively as shown in the back side of the boost converter.

Note : The boost converter do not have any marking.So use my picture during soldering.

Step 7: TRANSMITTER

The transmitter module contain the DHT11 sensor which is a relatively cheap sensor for measuring temperature and humidity of the environment.It is good for 20-80% humidity readings with 5% accuracy and for 0-50°C temperature readings with ±2°C accuracy.

I ordered the Barometric Pressure Sensor( BMP085) and rain fall sensor from eBay to forecast more weather data.For the time being I am happy with only temperature and humidity.

The weather data is measured by DHT11 ,processed by a Arduino nano/bread board arduino and transmit it wirelessly through a RF transmitter.

DHT11 Connection :

DHT11 sensor have 4 pins : 1->Vcc ,2->Data ,3->NC ,4 ->GND

DHT11 -->ARDUINO

Vcc-->5V
Data-->D8
NC --> No connection
GND-->GND
Connect a 10K resistor between VCC and Data pin of DHT11

RF Transmitter Connection :

The RF transmitter has 3 pins ( VCC,Data and GND).

RF Transmitter -->ARDUINO

VCC --> 5V
Data-->D11
GND-->GND

Note : Add a antenna in the RF transmitter to increase the range.click here

After connecting every thing, upload the Tx_code attached bellow

Step 8: MAKE a ENCLOSURE FOR Tx MODULE

I used a plastic box for transmitter module enclosure.

Make a hole in the top side of the plastic box for inserting wire from the solar panel.

Make small holes in the side wall (opposite face) for ingress of fresh air ( to measure the accurate data ).see the pics.

Place the charging circuit (made earlier) inside the box.

Take out the wires from li ion battery charger (IN+ and IN-)

Solder the positive terminal of solar panel to the positive terminal of diode and negative terminal of the diode to the red wire from the the charger.

Solder the black wire to the solar panel negative terminal.

For mounting the solar panel and battery holder I used skotch mounting pad.The mini bread board have inbuilt pad to stick.

Use tap to stick the wire firmly.

Connect the 5V (+) and GND (-) terminals of boost converter to the bread board red rail(+) and blue rail (-) respectively.

To test it expose to sunlight ,you will see red led in all (arduino,boost converter,charging) the boards will glow.

Step 9: RECEIVER

The receiver module receive the weather data by a RF receiver and it is processed by Arduino UNO .The processed data is displayed through a 20x4 char LCD display.You can also choose a 16x2 LCD also.The main reason for using a 20x4 char LCD is display is that I can display large number of weather parameters.

I add a I2C module to the LCD for reducing the number of connection with arduino (requires only 4 wires).

If you don't have a I2C module go to my tutorial on LCD tutorial for connection and example code.

LCD connection :

The I2C LCD have only 4 pins (GND,VCC,SDA,SCL)

LCD-->ARDUINO

GND-->GND
VCC-->5V
SDA-->A4
SCL-->A5

RF receiver Connection:

The RF receiver has 3 pins ( VCC,Data and GND).
RF Receiver -->ARDUINO

VCC --> 5V
Data-->D11
GND-->GND

Note : Add a antenna in the RF receiver to increase the range.click here

After connecting every thing upload the Rx_code attached bellow

Step 10: MAKE a ENCLOSURE FOR Rx MODULE

The receiver enclosure is card board box.

Mark the outline of lcd by using a pencil or marker.

Cut the marking portion by using a hobby knife.

Insert the lcd in to the cutting portion of the box.

Hard gue on the back side of the lcd to hold it firmly

Place the bread board receiver module prepared in the previous step.

I use a 12V dc adapter for powering the arduino uno.Make a hole in the back side of the card board box for inserting the dc adapter cable.

Step 11: POWER OPTIMIZATION BY USING SLEEP MODE

The weather data does not change frequently.So we can take reading at an interval of 5mins.As we are taking readings at regular intervals, it is a fantastic way to save lots of power. A system with appropriate sleep schedules can run for several months on just two AA batteries.We are so lucky that Arduino has several sleep modes that can be used to reduce power consumption.

This is most useful for any sensor networks.You can use this tricks in any of your stand alone sensor project.


After searching through the internet for using the sleep modes, I found a simple but powerful library by
Rocket Scream has a Lightweight Low Power library supports all AVR power down modes. Each mode has an associated library method that lets you control sleep duration using the watchdog timer.For a novice programmer like me it is very simple and easy to use.

How to use LowPower Library :

1. Download the library from GitHub
2.Extract the zip file to the arduino library in your computer.
3.Import the library in your code.
4.Write the following one line code for power saving.
"LowPower.powerDown(SLEEP_1S, ADC_OFF, BOD_OFF) ; "

You can also pass different arguments to shut off individual peripherals. For different argument and sleep time refer the table provided by Lightweight Low Power Arduino Library.


example code :

#include "LowPower.h"
void setup()
{
// No setup is required for this library
}
void loop()
{
// Sleep for 8 s with ADC module and BOD module off
LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF);
// Do something here
// Example: read sensor, log data, transmit data
}

Lets use it in the blink code of arduino IDE example

Apply "LowPower library" in Blink code


#include "LowPower.h" // import the lowpoer library
int led = 13;
void setup()
{
pinMode(led, OUTPUT);
}
void loop()
{
digitalWrite(led, HIGH);
LowPower.powerDown(SLEEP_1S, ADC_OFF, BOD_OFF); // instead of delay(1000) ;
digitalWrite(led, LOW);
LowPower.powerDown(SLEEP_1S, ADC_OFF, BOD_OFF); // instead of delay(1000) ;
}
Before using the Lowpower library current taken by arduino

51.7mA when led is ON
47mA when led is OFF

After using the Lowpower library current taken by arduino

34.93mA when led is ON
31.73mA when led is OFF


Are you happy to reduce 32.43 % power ?? Hey there is still room to reduce the power consumption.
Your arduino board have different power sucking components like power led,voltage regulator and USB interface chip which takes most of the power even when it is idle.For other alternatives see the next step.

Step 12: Alternatives for Power Saving

>> The simplest method to reduce the power consumption is by passing the voltage regulator in the Arduino board.

Buy a separate boost regulator circuit and connect its output to the 5 volt pin on the Arduino board, which bypasses the 5 volt regulator on board.This procedure is used in our project.

>> using a "bare bones" board instead of arduino board.
>> Disable the unnecessary led
>> If you do not need time accuracy, then use the Atmega 328 internal 8MHz crystal instead of a external 16Mhz crystal.

>> Operate Atmega 328 at 3.3V instead of 5V

>>Turn off sensor as soon as possible

To know more details on arduino power saving techniques click here


The maximum power saving is done by using a Bare bones board.By using a bare bone board the power consumption can be reduced to micro amps level during sleep period.You can see the above figure.

You can easily make this on a bread board by following the links bellow :

1.Arduino on a Breadboard

2.Arduino to a Microcontroller on a Breadboard
Make bare bone pcb board by following the links bellow :
Single Sided Really Bare Bones Board Arduino in EAGLE
I will highly recommend for the bare bone board for any battery driven projects ( like sensors).

Step 13: Battery Life Estimation

The battery life can be calculated by determining the average current for the circuit.

Use the following general equation to calculate average current.


Iavg = (Ton*Ion + Tsleep*Isleep ) / (Ton +Tsleep)

Ton (arduino is active ) = 250 ms =0.25s and Ion = 16mA

Tsleep = 5min =300s and Isleep = 200 uA (approx)

It is very difficult measure the current during the sleep period .Some time I got zero reading.

Iavg = 0.205 mA

Operating Voltage =5 V

Pavg=VxIavg =5x.205=1.026 mW

Li Ion battery capacity =3000 mAh

Battery voltage =3.7V

Power =3.7x3000=11100 mWh

Battery life = 11100/1.026 =10,818.7 hours = 15 months approximately

From the above calculation it is clear that theoretically by using a fully charged 3000 mAh Li Ion battery we can run the arduino for 15 months.In practical due to battery self discharge this figure may be different.

As the system is equipped with solar charging system ,we can run for few years without any interruption.

I hope you enjoyed by reading my tutorial.Please comments if any mistake found.

This project is entered in 3 competitions,please vote for me.

Thank you so much.

<p>Hello sir. Can i use 1s 3.7v li-po instead of 18650 li-ion?</p>
<p>Hello,</p><p>thanks for the work. <br>Could you please precise how many Wats photovoltaic cell is most suitable for this project? <br><br>Many thanks.</p>
<p>Hello!</p><p>I have something similiar in mind where a sensor detects if there is wind and sends it back to your smartphone so that you can prevent damage to your sunshade. </p><p>Do you think the solar panel can sustain an arduino with wifi shield? </p>
<p>I have a problem!!! </p><p>This report would have more information with</p><p> &quot;Show verbose output during compilation&quot;</p><p> enabled in File &gt; Preferences.</p><p>Arduino: 1.0.6 (Windows 7), Board: &quot;Arduino Uno&quot;</p><p>sketch_sep15a:39: error: 'POSITIVE' was not declared in this scope</p><p>sketch_sep15a.ino: In function 'void setup()':</p><p>sketch_sep15a:49: error: no matching function for call to 'LiquidCrystal_I2C::begin(int, int)'</p><p>C:\Users\ADMIN\libraries\Arduino-LiquidCrystal-I2C-library-master/LiquidCrystal_I2C.h:76: note: candidates are: void LiquidCrystal_I2C::begin()</p><p>sketch_sep15a:61: error: no matching function for call to 'LiquidCrystal_I2C::begin(int, int)'</p><p>C:\Users\ADMIN\libraries\Arduino-LiquidCrystal-I2C-library-master/LiquidCrystal_I2C.h:76: note: candidates are: void LiquidCrystal_I2C::begin()</p><p>I need a help!!!</p>
<p>It looks like you're missing the LiquidCrystal-I2C library from your files. Get it from here: <a href="https://github.com/fdebrabander/Arduino-LiquidCrystal-I2C-library" rel="nofollow">https://github.com/fdebrabander/Arduino-LiquidCrys..</a></p>
<p>I have same problem too(sorry, I can't speak English well)</p><p>exit status 1</p><p>'POSITIVE' was not declared in this scope</p><p></p><p>I just followed the system you gave.</p><p>Setup librarys...</p><p>but... Why did I get error?</p>
<p>reeplace this code line by LiquidCrystal_I2C lcd(0x27, 20, 4);</p>
<p>Hello, I am new to these Arduino things and I think this instructable is perfect to help me learn. First thank you for posting this. I am fully following your instructions letter for letter. I do have a question (besides the fact that I am having some problems with the sketches). My question is about the accuracy of the completed solar powered transmitter. Where is it placed outdoors, in the sun or in the shade? My concern is the whole transmitter circuit is enclosed in a plastic box, wouldn't there be excessive heat build up? Would this project be accurate if I placed the box in the shade and ran a power wire to the solar panel located somewhere close but in the sunlight? </p><p>Again thank you for this great instructable.</p>
<p>Hello, Can i have some practical electronics question ? Can you explain me why you use Diode -IN4007 in this circuit ? Is it mandatory ? </p>
<p>Yes, it essentially makes a one-way connection between the solar panel and the battery. Current can flow from the solar panel to the battery but cannot flow from the battery to the solar panel.</p>
<p>Hi. This diode is necessary to place, because if it is not placed and there is a shadow on the panel, this consumes energy. That is, if there is a stain on the panel, that part of the panel will consume energy. With the diode we get that it can not consume.</p>
<p>Hello . I did this project, but I used DHT22 and much more accurately measured. Tell me what it is &quot;HI&quot; on the display, because the project has no other sensor than DHT and it shows some strange values.</p>
<p>I liked your project, you can also upload to a cloud server and monitor wirelessly by using iot application platform such as thingspeak.com</p>
<p>I have used the DHT22 which can measure negative temperatures as well. <br><br>But with this code I have a missing datapoint for temperature when it's in minus. I don't manipulate anything with the input on the receiver end so the problem must be in the sender code.</p>
<p>Hello:<br>Thank you for all the project information.<br>Got it!</p>
<p>nice project </p>
<p>Hi! Can i have the schematic diagram for this project?<br>Thanks a lot!</p>
<p>what about Li on battery ? if -20C outside.</p>
<p>Hi Deba</p><p>Thank you<br>for this very nice instructable. I would like to build a solar powered weather<br>station under this model. But I live in Switzerland where sunlight can be<br>scarce especially during autumn and winter. Do you know how much sunlight the<br>system needs? Would you recommend increasing the solar panel voltage, current,<br>or battery capacity, or the three things?</p><p>Also, a 4V<br>&ndash; 200 mAh panel is no longer available on e-bay. Any replacement option?</p><p>Thank you<br>very much for your support</p><p>Sebastien</p>
<p>http://www.ebay.co.uk/itm/201679046412?_trksid=p2057872.m2749.l2649&amp;ssPageName=STRK%3AMEBIDX%3AIT</p>
i want make it for my final year projects.
<p>Hi, can I make a similar connection to power an arduino plus a servo motor? Can I make it so that I don't need to disconnect the solar power ever? Can I simply keep it running?</p>
<p>You did a really good job documenting and explaining your project, good pictures, details, links - really useful.</p>
<p>The pro nano can be replaced by a atmega 328<br><br>Thank you</p>
<p>I think if you remove all the LEDs you will already reduce energy consumption a lot.</p><p>The only other thing that's different from a barebones chip is the extra 5V regulator on the Pro Mini.</p>
<p>Yes you can replaced.</p>
<p>This board might be a good option if you're looking for low power consumption: https://bitbucket.org/talk2/whisper-node-avr/overview it can be used with standard AA batteries</p>
<p>Instead of advertising your product here which is: </p><p><strong>Release Date:</strong><br>TBD</p><p>You should be focusing on the same goal to fix this project for free. His design is obviously faulty. Anyone who builds this I give your station 3-4 weeks tops with a 6000mAh battery before it goes down and then the battery will never recharge again to power the station.</p><p>I have built this setup just like him with bare bone atmega 326P (although using external crystal oscillator, it doesn't change much). My station is using the lowpower library just like his and sends data in every 5 minutes.</p><p><a href="https://www.instructables.com/id/RF-315433-MHz-Transmitter-receiver-Module-and-Ardu/" rel="nofollow">https://www.instructables.com/id/RF-315433-MHz-Tran...</a></p><p>By this article the RF transmitter modul works from 3-12V so I will take out the voltage booster (which I believe drains off all the energy here) and let you know the results in 2 months.</p>
I had a problem that the display shows no information, I hope 5 min and nothing, I have everything connected like this on the page, like the Tx and Rx codes
<p>Solved. Used an older version of arduino ide, all working fine now!</p>
<p>Congratulations !!!</p>
<p>good morning , you can work with Arduino UNO R3 ?</p>
<p>Yest it will work with Arduino UNO R3.</p>
<p>I made the circuits, but the LCD shows me wrong numbers, and when I open the serial monitor to verify that the receiver is working i cant find anything there</p><p>help?!!</p>
<p>I think you have problem in software.Though not sure.</p><p>Or you may check the Arduino Vcc.Is it sufficient ?</p>
<p>Beautiful project! I'm stuck with the receiver :( I just see a blank screen and don't know what to do. Everything looks ok, but I can't even show the icons! On the other hand, how can I be sure the transmitter is transmitting? </p><p>Thanks!</p>
<p>You can confirm it by checking your receiver arduino serial monitor.</p><p>connect your receiver arduino to the PC through a USB cable,open arduino IDE and see the serial monitor.If you receive the data then it confirm transmitter is transmitting.</p>
<p>Hey deba168, I was running into a similar issue. After some debugging, I determined that the vw_get_message call never returns true so I'm pretty sure the receiver is not getting any data. The circuit appears to be complete and I verified that the transmitter and sensor are working, what do you think would be the most likely cause of that?</p>
<p>Thanks for the advice, but the problem was that lcd doesn't show anything until it receives data from transmiter. So if I power the transmiter first, I would have to wait 5 minutes until getting data (or press reset). Once I have discovered it, everything is ok ;)</p>
<p>Hi can someone help me please. I have made this and having trouble. If i use a different transmitter and code i can get the details on the display but making this project nothing no serial data for transmitter or reciever. I'm a beginner and please correct me if I'm wrong. When the transmitter data pin is connected to D11 in the instructions but in the sketch it is set as D12 ???? can someone explain this please and maybe why I'm getting no serial data from either module. Thanks.</p>
<p>Using 2x AA NiMh batteries with a dc-dc booster you say to </p><p>&quot;Solder the '+' terminal of boost converter to the battery positive terminal.</p><p>Solder the '-' terminal of the boost converter to the battery negative terminal.&quot;</p><p>But<br> where do i solder on the solar panel? in parallell to the battery? if <br>my solar panel can produce 6v in peak conditions how will the booster <br>that can take 0.9v-5v handle that?</p><p>Or should i skipp the booster <br>and use a arduino pro mini (3.3v) version and connect the solar/battery <br>to the vin pin (the one with the built-in voltage regulator)?</p><p>Another note: i'm planning on using the solar powerd arduino to run a waterpump to water the flowers rather than for sensors.</p><p>It will be in sleep and waking up about every 3 hours and checking if its light or dark out, if it's dark it will check for soil moisture and then if needed start the pump for ~10 seconds.</p><p>do you think this rig will be able to run like this or will i need to add more batteries and solar panels for it?</p>
<p>Where the code of this project? (Programation)</p><p>thx</p>
<p>The code is attached in step-7 and step-9.</p><p><a href="https://www.instructables.com/files/orig/FQS/YAB6/HZV3O6IZ/FQSYAB6HZV3O6IZ.txt">https://www.instructables.com/files/orig/FQS/YAB6/H...</a></p><p><a href="https://www.instructables.com/files/orig/F3S/72IM/HZS8WTVS/F3S72IMHZS8WTVS.txt">https://www.instructables.com/files/orig/F3S/72IM/H...</a></p>
<p>Hi</p><p>I did not notice any details about transmission range. What is the maximum?</p>
Hai. <br>I have a problem.. There were no display on the lcd.. What was the possible problem? I need help!!
<p>Make sure that hex address (0x27) is the right one for your LCD display The one that I am using is 0x3F. If your not sure if this is the problem try running sketch named LCD_Hex_Address. This program will seek out the serial interfaces proper address. Hope this will help you.</p>
<p>Hello, I want to made your proyect, but I want to include the barometer sensor and the rain sensor. How can I include those sensors on the arduino placard and the software. thanks</p>
<p>Hello</p><p>i have problem with my display,do you know what it could be?</p>
<p>check your display wires and pin mapping. also might be the fact that the display contrast is to high and the characters are not visible. there should be a potentiometer on the back of the display from where you can tweek.</p>
<p>Made everything 1:1 except I used two Nanos, displays stays empty. </p><p>tripple checked everything, I have no clue why it is not working. </p><p>Checked all the comments, gave both units enough time and so on :( pretty dissapointing. </p>

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Bio: I am an Electrical Engineer.I love to harvest Solar Energy and make things by recycling old stuffs. I believe &quot;&quot;IF YOU TRY YOU MIGHT ... More »
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