Feather ESP32-S2: turn on I2C power after reset

[dhalbert]

This is the pretty much the same as #5776, but is a PR against 7.1.x instead of main. I read the code and could not understand why it didn't work, and after trying it myself, I was unable to repoduce the D7 in use message.

@ladyada, could you test, in your own way? I was using this, with the DigitalInOut commented out and not.

import time
import board
import digitalio
import adafruit_bme280.basic

# Test with and without this.
# power = digitalio.DigitalInOut(board.I2C_POWER_INVERTED)
# power.switch_to_output(False)

i2c = board.I2C()  # uses board.SCL and board.SDA
bme280 = adafruit_bme280.basic.Adafruit_BME280_I2C(i2c)

while True:
    print("\nTemperature: %0.1f C" % bme280.temperature)
    print("Humidity: %0.1f %%" % bme280.relative_humidity)
    print("Pressure: %0.1f hPa" % bme280.pressure)
    print("Altitude = %0.2f meters" % bme280.altitude)
    time.sleep(2)

[jepler]

I'm not sure about this change. Specifically, I think it may behave differently when merged to main, where we've taken

• esp32s3-box: enable display #5674

and specifically fae6d47 where we now ensure that a "never reset" pin continues is marked as "in use" after reset_all_pins().

This was needed to resolve a problem where the state of a displayio backlight pin was lost over soft resets.

[dhalbert]

That must be why it didn't work when I tested with an artifact from #5776.

[dhalbert]

@ladyada and I talked about turning on the power-enable in reset_board() instead of board_init(). reset_board() gets called each time the VM shuts down. That would cause any setting of the pin not to be sticky from boot.py to code.py, but that could be OK.

But #5674 makes the backlight pin unavailable for setting manually, I think. Is that OK?

[dhalbert]

and specifically fae6d47 where we now ensure that a "never reset" pin continues is marked as "in use" after reset_all_pins().

This is true only on espressif. As another example, something similar is done for CPB, so we might want to be consistent across ports.

I think never_reset is being overloaded with responsibilities. Maybe we need to separate "never reset" and "never allocate".

[ladyada]

that did it! works great

[ladyada]

can u cherrypick into 7.1?

[dhalbert]

can u cherrypick into 7.1?

This is already against 7.1.x, so it will go into 7.1.0-rc.1. We'll merge it into main as well.

[ladyada]

ok rad thanks! this should help with customer confusions