Introduction: RedBitOne - Tiny But Powerful
A tiny atmega328p-au breakout with all the power of the Arduino(TM) UNO, see it driving your next micro project!
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OPEN SOURCE --- all files are at THE GITHUB
feel free to use the schematic! its pretty basic but it's designed to be made into a tiny board and the kit contains the board and parts all in one package!
Available as a kit or fully assembled device from My Tindie Store with all specs and capabilities listed there. This will serve as assembly instructions and programming instructions so for the Kit continue with the assembly on the following pages and for a pre assembled model please skip to "Programming"
Designed to be squeezed into the tiniest of projects where space is key, but as powerful as an Arduino(TM) UNO running on the same chip. At heart its an Atmega328p-AU breakout board with 0.1" spacing, the most basic support circuitry and an isp port for programming. This allows it to be hackable and to adapt, power it with any voltage from 2.7-5.5V! it will (probably) survive and keep going! change the fuse bits! mess with the clock! then stuff it into a tiny enclosure and watch it drive your tiny robot!
So to program this you need and ISP programmer BUT - ISP free's up a bunch of possibilities and is much more reliable and faster than talking over serial via a converter (Like the UNO) and both require a programmer to talk to a computer!? why waste your time with serial! taking up two of your pins, valuable Uart ports and Bootloader space... Ugh. I've tried a USB bootloader (eg Adafruit's Pro Trinket ) but that also takes up 2 pins! and the bootloader takes ages to load, with ISP turn it on and you programs off! just like that - no waiting.
ISP programmers used to be expensive, but now there just as easy to get and MORE useful than an ftdi serial adapter! I would recommend the USB tiny ISP, FAbisp both use the same drivers, orUSBasp
And hey! if you haven't got one just send me your code a firstname.lastname@example.org in INO or HEX and ill put in on there for ya!
What you get
A 1" by 1" board (will fit in breadboard if 2 opposing rows are populated) and will fit in a perfboard
A 16 MHZ crystal setup
pull-up reset resistor
Built in Power-LED In your choice of colour
plenty 'O headers
All the necessary pins are broken out for your project including reset - the new board has an updated silkscreen with pin functions labeled as well (pictures are of slightly older board)
Fuse Bits-Same as UNO
Voltage-5.5 to 2.7 (no reg. so do what ya want)
Want anything else? email me for inquiries
It comes as a kit with the chip setup to run at 16MHZ and pre-tested running BLINK on pin 13 but that 0.8mm TQFP can be a pain, so i will assemble it by hand if that's required. Parts are 0805 and the LED is 0603, the Crystal is through hole to make it easy to hand solder. Again if you would like software pre-loaded instead of Blink just throw me a call.
Shipping - orders made before 12 AM GMT will ship before 7:30 GMT that day on all business days. Parts come in small Jiffy padded envelopes with extra bubble wrap - inside antistatic bag with quick reference assemble instructions as well as a checklist and Serial Number. Full assembly instructions will soon be up on instructables.com but it should be plug and play so for now just give a call if you need help. To program plug into ISP and use >UPLOAD USING PROGRAMMER on Arduino IDE having selected your programmer
Finally stay posted for the Redbit One Pro and the RedISP - an upgrade with a built in ISP and a Tiny AVRisp
Check out The Custom Geek and his "1 square inch" board, similar but it instead uses ftdi.
Thanks for checking me out!
Step 1: Assembly 1 - Check You Have Everything
Make sure everything is there!
- 1 x PCB 1 x ATMEGA328P-AU
- 1 x Crystal 16MHZ
- 1 x 10K - 103
- 1 x 200R - 201
- 2 x 18Pf capacitors
- 1 x LED - R/G/B
If anything is missing email me with your serial number and an enquiry
heres what you will need
- Soldering iron with appropriate tip (hoof is recommended)
- Solder (as fine pitch as you can find)
- a pcb holder
- extra flux
- solder wick (i recommend soldamop)
and i recommend
- electrical tape
- hot air gun
Step 2: Soldering the TQFP-32
Soldering the chips can be tricky but is do-able
Tweezers are used to hold the package and the polarity means the circle in the chips corner should match up with the one shown, Your flux pen will be used a lot so get it ready - use it with gusto whenever reflowing solder as the flux that is in the core has already gone. Use your solder wick to mop up any spills and bridges
- my personal favourite teacher is Dave from the EEVblog and his drag soldering
But really just google TQFP32 soldering and you will find loads of tutorials on soldering, the way you solder it is down to preference. Unfortunately Dave has a thermal pad chip and doesnt need to solder corners to hold the chip in place, so heres another helpful video from The Custom Geek that does the pins individually.
Hes making a similar board that uses FTDI - you can buy it from his shop and dont worry - they look similar but he knows about the REDbit and it's A-OK
Step 3: The Capacitors, Resistors, Led and Crystal
I would recommend soldering the parts in the order above starting with the 0805 resistors and capacitors and led (0605). The resistors and capacitors have no polarity so do wack them on anyway.First tin one pad of each part with of each some solder ideally the pad on your side that uses the iron so reflowing will be easier. Use tweezers to pick up each part and place them on their pads then reflow the solder after adding flux - this will tack the parts in place. Finally solder the other side of the part and hey presto
C1 and C2 are identical and shown on the insert slip (small browner package without marking)
R2 is marked 201 and is 200 ohm for the LED
R1 (moved to allow mounting hole on new models) is 103 and 10K ohms for reset pullup
Crystal is 16MHZ
LED is well, an led, and the smallest - positive goes to board edge
The LED as its 0603 can be quite fiddly and has a polarity shown on the slip that comes with the REDbit. Its also super easy to loose.
Heres a video that explains it well by itsInOurKernel
The crystal has no polarty and is through hole - Ill assume you can solder it if you're attempting a tqfp
Add headers for isp and pins as necessary.
Step 4: Programming
Whether a kit or a pre assembled model the board is setup as an uno and running blink - all models are tested before shipping. To program the board an AVR isp is required - stay tuned on my store for a 12 dollar AVR isp I'm currently working on! but for now a USBtinyisp or AVRISP MK2 or even an uno running the Arduino ISP sketch! simply plug the ISP header (check orientation - dot is pin 1) in to your programmer and write data as an Atmega328p or UNO.
To use the Arduino IDE select your programmer after plugging it in (no need to select port) and then press upload using programmer. (see above)
AVRdude works similarly but use arguments "-c $YOURPROGRAMMER$ -p atmega328p"
Feel free to mess with the fuses but if you brick it i may feel less inclined to send a new one. the Fuses are that of an UNO.
- Voltage - 4.5-5.5 volts recommended for 16MHZ operation (lower voltages are overclocking)
- Current - depends but chip draws very little apart from large IO changes which always cause current spikes
- Speed - 16MHZ (16 million clocks a second)
- IO -20 (6 PWM 6 ADC)
- ALL IO broken out and Reset line
- Size 1"-1"
- Fuse bits LOW-0XFF HIGH-0XDE EXTENDED-0X05
- Anything else? email email@example.com
Thanks for reading!