The latest firmware has a new half duplex UART mode. This is a single data wire open collector bus that requires a pull-up resistor.
This mode is specifically designed to work with SIM cards with 8/E/2 UART settings. The UART runs in the RP2040 PIO though, and should work with all the same settings as the normal 2 wire UART mode (data bits, parity, stopbits).
You can use this mode to get the ATR from mobile phone SIM cards, as well as debit/credit chip cards.
This week is going to be pretty focused on hardware: shipping the next batch of Bus Pirates, and 5 adapter boards should start production. I’d like to get through this list of fixes though:
- SPI mode flash chip variable not zeroed bug, flash dump unknown chips by range
- Remove I2C clock stretching or make it optional
- Rework BIO library a bit. Test for buffer direction before changing pin IO. New bio2buf and bio2pin functions. Maybe mode system_claimpin to bio
- scope - clean up new command, check freezing issue with Paul, detailed help
- universal power and pullup check helper function, install everywhere
- SIM card query and ATR parser in half duplex UART mode