18 Jun 2023

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Pico-DE0 notes

I implemented basic command argument support (getarg_str and getarg_u32).
New commands:
- o {outmask} - Configure outputs: Each high bit in outmask will configure its corresponding GPIO to be an output.
- i {inmask} - Configure inputs: As above, but to configure GPIOs as inputs.
- = {set_mask} {set_vals} - Set GPIOs identified in set_mask to corresponding values in set_vals.
- r - Software reset. May not allow USB-CDC to reconnect properly? Not sure yet. NOTE: Wokwi doesn't support this (watchdog-based) method.
It doesn't look like the pico-sdk has a high-level Hardware API call to get the "direction" of all GPIOs in one go, but from reading the pico-sdk source it looks like reading the SIO_GPIO_OE register is the way to go, and the nice way to do this is via sio_hw->gpio_oe
NOTE: The code defines GPIO_MASK which is used to prevent changing the state of any GPIOs that have special Pico functions.
With the new commands above I've now been able to test outputs, and the DE0-Nano design appears to detect them as expected.