add retries and delays to work around ESP32-S3 problems

[dhalbert]

ESP32-S3 has some issues with the clock-stretching and sleeping done by the LC709203F. See https://github.com/adafruit/circuitpython/issues/6311.

• Add retries when scanning for the device, and also add some delays during setup. This seems to mostly ameliorate the problems on the S3.
• Raise ValueError for bad args, not AttributeError.
• Raise OSError instead of RuntimeError on CRC failure. This makes it easier to catch all read/write failures so you can retry.

Tested with this program. Note the try-except which catches OSError. There can still be occasional failures, so it's good to catch and retry.

import time
import board
import busio
from adafruit_lc709203f import LC709203F, PackSize

uart = board.UART()
battery_monitor = LC709203F(board.I2C())
battery_monitor.pack_size = PackSize.MAH400

while True:
    try:
        print("Battery Percent: {:.2f} %".format(battery_monitor.cell_percent))
        print("Battery Voltage: {:.2f} V".format(battery_monitor.cell_voltage))

        uart.write(b"Battery Percent: {:.2f} %\r\n".format(battery_monitor.cell_percent))
        uart.write(b"Battery Voltage: {:.2f} V\r\n".format(battery_monitor.cell_voltage))
    except OSError:
        print("retrying reads")

    time.sleep(2)

@Gingertrout @BeatArnet @mopore @ThomasAtBBTF Could you try this changed version and see if it works for you? Thank you. You just need to copy the adafruit_lc709203f.py file in this pull request to your CIRCUITPY drive, which will override what is in your lib/. You should be able to remove the i2c.scan() code from your existing programs, since this does approximately the same thing.

New code is available at https://github.com/adafruit/Adafruit_CircuitPython_LC709203F/blob/1007e4c96bc465204de0cb5a3684022e9e0fb71b/adafruit_lc709203f.py

[BeatArnet]

After downloading the latest version of the adafruit_lc709203f.mpy library and running your sample code on my feather_s3_tft I got the following errors:

%Run -c $EDITOR_CONTENT Zurückverfolgung (jüngste Aufforderung zuletzt): Datei "", Zeile 7, in Datei "adafruit_lc709203f.py", Zeile 132, in init Datei "adafruit_lc709203f.py", Zeile 136, in init_RSOC Datei "adafruit_lc709203f.py", Zeile 257, in _write_word OSError: [Errno 116] ETIMEDOUT

[dhalbert]

@BeatArnet The proposed fix is not yet available as .mpy. Please try: https://github.com/adafruit/Adafruit_CircuitPython_LC709203F/blob/1007e4c96bc465204de0cb5a3684022e9e0fb71b/adafruit_lc709203f.py

[BeatArnet]

Unfortunately, after some impressive results…

Battery Percent: 100.00 %

Battery Voltage: 4.19 V

Battery Percent: 100.00 %

Battery Voltage: 4.19 V

Battery Percent: 100.00 %

Battery Voltage: 4.19 V

Battery Percent: 100.00 %

Battery Voltage: 4.19 V

Battery Percent: 100.00 %

Battery Voltage: 4.19 V

Battery Percent: 100.00 %

Battery Voltage: 4.19 V

Battery Percent: 100.00 %

Battery Voltage: 4.19 V

Battery Percent: 100.00 %

Battery Voltage: 4.19 V

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[dhalbert]

@BeatArnet hmm, I saw a few missing reads, but not continuous as you did :slightly_frowning_face: . Are you using exactly the same test program, and which board are you testing on?

[BeatArnet]

I used your sample-code and the latest library *.py. I have an Adafruit S3 TFT board.

[tekktrik]

I'll defer to @dhalbert but I agree with you.

Also, I didn't fully realize until now that CircuitPython implemented the for/else combination, cool! I think this is the first time I've actually seen it in action.

[dhalbert]

@FoamyGuy @tekktrik I did not merge it because @BeatArnet still had trouble. But it may be particular samples. So ok, let's merge it, and it will fix the problem at least some of the time.

[BeatArnet]

I could solve the problems, using the following code:

# The following code for scanning the I2C addresses is necessary so that the voltage can be measured
BATTERY_MON_ADDRESS = 0x0B  # Address for ESP32-s3 tft Feather

def hack_for_i2c_issue():
    i2c = board.I2C()
    while not i2c.try_lock():
        pass
    running = True
    try:
        while running:
            print("I2C addresses found:", 
                [hex(device_address) for device_address in i2c.scan()]
            )
            # time.sleep(2)
            running = False
        return i2c
    finally:  # unlock the i2c bus when ctrl-c'ing out of the loop
        i2c.unlock()

try:
    print("Searching for battery monitor...")

    i2c = hack_for_i2c_issue()
    battery_monitor = LC709203F(i2c)

For me, the problem is solved with the above hack.

[dhalbert]

@BeatArnet The code I added is similar to your hack, but only tries three times to wake up the LC709203F. However, if it doesn't succeed, it will throw an exception. So I don't know why your eventually gets read failures. Perhaps the sensor is going back to sleep in a scenario I hadn't envisioned. We could retry reads a few times as well.