Author Topic: Could really use some pinout / functionality information (Read 12906 times)

swz · « **on:** August 23, 2012, 10:22:22 am »

I'm very excited about Digispark! Great concept and it looks like it's being thoughtfully developed. I'd like to have projects ready to go when I get my first units, but I can't really scope a design without some additional detail. The Kickstarter documention lists multiple uses for the output pins, but there are too many to be mutually available at the same time. The USB / pin 0,1 conflict is well described, but I can't tell how SPI/I2C, ADC, PWM are interleaved on the remaining 4 pins. I have potential uses for each function, but I can't determine how much I can pack on a single Digispark without knowing how the functions map to the pins. Please provide at least this functionality, if not some example sketches for the different capabilities. Will there be sample sketches for the standard shields?

Thank you.

sparr · « **Reply #1 on:** August 23, 2012, 10:52:31 am »

P0-P5 on the digispark are PORTB0-PORTB5 on the ATTINY85.

http://www.atmel.com/Images/doc2586.pdf

chibi · « **Reply #2 on:** September 15, 2012, 10:01:13 am »

Does anyone have the recommended PCB size and pin locations for Digispark shields as well as what is available on each pin?
I want to make a shield using Eagle and would prefer to have the pins line up.

sparr · « **Reply #3 on:** September 15, 2012, 12:42:26 pm »

the official shield footprint will be published soon! we know that the two headers are on breadboard spacing (for power rails if you leave off the VIN pin), so that\'s enough to position them relative to each other

Smolder · « **Reply #4 on:** September 21, 2012, 06:30:26 am »

I\'ve been really excited by this as well, excited enough to make some wild speculations. I worked up this guess as to the digispark footprint. This is just my own guess based off of the currently available images, you should in no way use this as a reference or base anything off of it. I\'m going to, but you shouldn\'t since I could easily be totally wrong.

http://i795.photobucket.com/albums/yy232/smolder_bucket/DigisparkPCBLayoutv10-01_zpsc415f306.png

Bluebie · « **Reply #5 on:** November 03, 2012, 06:40:15 pm »

PB3 and PB4 are used for the USB connection and have some zenner diodes and things which limit their voltages. This leaves PB0, PB1, PB2, and PB5 completely free when using the USB interface. Two 8-bit PWM channels, a USI port which can do SPI, Serial, and I2C stuff, differential analog input with optional 20x gain, analog reference input, hardware interrupt INT0, pinchange interrupts, two regular analog inputs, and a digital analog comparator (is one pin\'s voltage higher than the other? yes or no - this is much faster than full analog sampling)

The USB pins when not attached to a computer also offer two more analog inputs limited somewhat to a range of probably about 0 volts to 3.6 volts due to USB circuitry probably with a roughly 1.5kohm pullup on PB3 IIRC which affects it\'s use as an analog or digital input. These two pins can also be used to get one more PWM output, or a pair of PWM pins where one is the inverted output of the other - handy for driving motors.