This page contains the (relatively unchanging) information about v0.1 of the SARduino644 board.
|SARduino644 v0.1||everything (.zip)||.sch .png||.brd .png||.zip|
Bill of Materials
Stan Hall sent in a Mouser BOM of all the parts listed below, for easy ordering.
|IC1||ATmega644P||Microcontroller (or ATmega1284P)|
|R1||10K ohm||Pullup resistor for RESET switch|
|Y1||16MHz Crystal||Oscillator (or 16MHz Ceramic Resonator, omit C1,C2)|
|C1,C2||18-30pF Cap||Capacitors for Crystal (match required value)|
|C4,C5||0.1uF Cap||Bypass capacitors for MCU, consider putting right at 5V/GND and A+/GND pins instead of labeled positions|
|JP10||1×6 header||6-pin FTDI cable programming connection (optional)|
|SV1||Reset button||6mm x 6mm tactile momentary switch|
|JP6||1×3 header||3-pin power selector (external or USB)|
|ICSP||2×3 shrouded header||Standard AVR ICSP header|
|SW1||Reset button||6mm x 6mm tactile momentary switch|
|EXTERNAL POWER SUPPLY OPTION:|
|D1||1N400X||Input protection diode (e.g., 1N4001 or 1N4004)|
|J?||2.1mm jack||External Power Jack|
|VR-TOP||7805||5V Regulator (any IN-GND-OUT should work, or 3V3 if you want that)|
|C6,C7||10uF-100uF||Power Supply Filter Caps|
- The reference designators are all jacked up on this one.
- Most passives are not labeled by value on the PCB.
- It would be really handy to have more prototyping area in the spare space, it’s kind of hard to do simple stuff with the 644 pins otherwise.
- There is no cap on the reset line from the FTDI to support auto-reset.
- Some extra power and ground rails would be nice for prototyping.
- It would also be nice to have a pad for raw external VIN, in case we’re not using a 2.1mm jack.
- C4 and C5 are really bypass caps for the microcontroller, and should be as close to the VCC pins as possible. Omit from marked placement, and instead put right across power/ground pins on each side of the microcontroller.