I'm wondering if its possible to use the ADC pin as a secondary AUX pin. And if that's possible, then I'll modify the firmware and send Ian a patch (or whatever).
I'd like to use the Bus Pirate for the Xbox360 JTAG hack; I'm just missing one more pin.
How many pins do you need? The ADC pin goes through a resistor divider, so it's not to terribly great as an output.
i need a total of 7 including GND, and i think its v3.3 chip voltage.
something that may or may not work.
I have been thinking of using some of the pins that are mapped to the icsp header for I/O. as far as i can see, it should be quiet easy to get an extra 2 maybe 3 i/o from there on a temparary basis at least.
anyway im sure it has its downsides but it might be something to think about
That's what I was going to say - use the ICSP header pins. They're RB0 and RB1, so they even have PPS (for SPI, timers, etc), BUT they're analog pins so they're not 5volt tolerant.
im not sure what other i/o pins are left on the pic. but ian maybe its might be worth routing them to some extra i/o pins on the next hardware revision.
more i/o is allways good
There's a couple, but the components are so dense that there's not much room to route any extra traces on a 2-layer PCB. I removed the serial header tap in v3 because I had to make room for other stuff, so it's a trade-off now unless the PCB gets bigger. Not that I object to that, but I'd rather not make another BP revision for a while, and I'd like to move to a chip that's in better supply if I ever do.
Kind of unrelated - Eric at Seeed sent me a sample housing (case) for the Bus Pirate v3, and he's looking for a tool-box type case for the Bus Pirate, cables, probes, and perhaps a test PCB like the 3EEPROM. I'm sure everything would be offered loose, but I'd like to see a bundle with housing + case + USB/probe cables + 3EEPROM. Any thoughts? I'll try to post a picture of the plastic housing soon, it's a perfect fit, just needs some holes.
To me, having ADC is less useful than having additional IOs. As soon as I can figure out the Microchip Docs, I'll see what I can hack together in the firmware.
Might take me more time than it took to write the GUI program from scratch, it's kinda been a while since I did any uController programming.
Let me know if there's anything you want me to code. I'd add an option to toggle the ADC pin, but it's not useful as an output because of the resistor voltage divider that lets it measure up to 6.6volts. You could use it that way if you removed the resistors, but like the ICSP pins, it's analog so 3.3volts max.
maybe is it worth adding a way of toggling the icsp pins?