avr:t85:littlewire
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- | # LittleWire | ||
- | # Overview | ||
- | |||
- | I can't think of anything to add to the official description of the LittleWire. For me, it's a cool tool to build, and a cool tool to have on hand, mostly for programming AVR chips. | ||
- | |||
- | * __usbtinyisp__ compatible AVR programmer. | ||
- | * 4 channel GPIO. | ||
- | * ADC with 10 bit resolution. | ||
- | * 2 parallel hardware PWM outputs. | ||
- | * SPI interface. | ||
- | * I2C interface. | ||
- | * 1-Wire interface | ||
- | * WS2812 RGB LED interface. | ||
- | * Multiple device support. | ||
- | |||
- | |||
- | # Perfboard | ||
- | |||
- | A while back, I used a round piece of perfboard to make a smd-like LittleWire... No schematics, it's directly inspired from the Schematic of the Little Wire. The only difference is: D+ and D- are swapped to make it easier to solder... | ||
- | |||
- | {{: | ||
- | |||
- | It's a little bit messy, but it worked, and still does its job ! | ||
- | |||
- | # SMD | ||
- | |||
- | I was a little bored and wanted to practice SMD soldering, just for fun. So I made an SMD version of the LittleWire. | ||
- | |||
- | * Small footprint | ||
- | * MiniUSB connector | ||
- | * Easy to use header => Can be plugged in a breadboard ! | ||
- | * Micronucleus bootloader | ||
- | |||
- | ## PCB | ||
- | I still haven' | ||
- | Sorry, it's a little bit crowded, but everything should fit nicely... 600 DPI image, as usual around here... | ||
- | |||
- | {{: | ||
- | |||
- | Pin 1 of the Attiny is on the top right of the PCB, near D3 | ||
- | |||
- | ## Components | ||
- | |||
- | Required | ||
- | |||
- | * D1, D2: 3.6v Zener Diodes | ||
- | * R1, R2: 39 Ohms | ||
- | * R3: 1.5 kOhms | ||
- | * C1: 1 µF | ||
- | * Attiny85 | ||
- | * 6 Pins Header, straight | ||
- | * MiniUSB connector | ||
- | |||
- | Optional | ||
- | |||
- | * C2: 68 nF | ||
- | * D3: Blue LED | ||
- | * R4: 1 kOhms | ||
- | |||
- | |||
- | ## Pinout | ||
- | |||
- | Pin 1 is the closest to the USB port. The pinout is then: | ||
- | |||
- | 1. Vcc | ||
- | 2. Gnd | ||
- | 3. /Reset | ||
- | 4. SCLK | ||
- | 5. MISO | ||
- | 6. MOSI | ||
- | |||
- | Once you get used to this pinout, it's very handy to use ^^ | ||
- | |||
- | ## Firmware | ||
- | |||
- | I only re-host theses files in case the original goes missing. I haven' | ||
- | |||
- | Flash an empty chip with: | ||
- | avrdude -c usbtiny -p t85 -U flash: | ||
- | And then use the Micronucleus software to flash the LittleWire firmware. | ||
- | |||
- | ## Result | ||
- | |||
- | {{: |
/home/share/www/redox.ws/wiki/data/attic/avr/t85/littlewire.1402701950.txt.gz · Last modified: 2023/11/24 21:55 (external edit)