jaredwolff scratch that. I just put the Argon on a breadboard with just 2 pullup resistors for the I2C bus:
>>> print("I2C addresses found:", [hex(device_address) for device_address in i2c.scan()])
I2C addresses found: []
Then I added an MCP9808 temperature sensor:
>>> print("I2C addresses found:", [hex(device_address) for device_address in i2c.scan()])
I2C addresses found: ['0x18']
And then I plugged the Argon into the AQW:
>>> print("I2C addresses found:", [hex(device_address) for device_address in i2c.scan()])
I2C addresses found: ['0x8', '0x9', '0xa', '0xc', '0xd', '0xe', '0x10', '0x11', '0x12', '0x13', '0x14', '0x15', '0x16', '0x18', '0x19', '0x1a', '0x1c', '0x1e', '0x20', '0x21', '0x22', '0x23', '0x24', '0x25', '0x26', '0x28', '0x29', '0x2a', '0x2c', '0x2e', '0x30', '0x31', '0x32', '0x34', '0x35', '0x36', '0x38', '0x39', '0x3a', '0x3c', '0x3e', '0x40', '0x41', '0x42', '0x43', '0x44', '0x45', '0x46', '0x48', '0x49', '0x4a', '0x4c', '0x4e', '0x50', '0x51', '0x52', '0x54', '0x55', '0x56', '0x58', '0x59', '0x5a', '0x5c', '0x60', '0x61', '0x62', '0x64', '0x65', '0x66', '0x68', '0x69', '0x6a', '0x6c', '0x6e', '0x70', '0x71', '0x72', '0x74', '0x76']
A visual inspection of the AQW shows nothing out of the ordinary, apart from the resistor R1 being absent. Is that correct? According to your schematics, there should be a 100k resistor.
I soldered a 120K resistor on the empty R1 pads (didn’t have a 100K) and the output changed slightly:
>>> print("I2C addresses found:", [hex(device_address) for device_address in i2c.scan()])
I2C addresses found: ['0x8', '0x9', '0xa', '0xc', '0xd', '0xe', '0x10', '0x11', '0x12', '0x13', '0x14', '0x15', '0x16', '0x18', '0x19', '0x1a', '0x1c', '0x1e', '0x20', '0x21', '0x22', '0x23', '0x24', '0x25', '0x26', '0x28', '0x29', '0x2a', '0x2c', '0x2e', '0x30', '0x31', '0x32', '0x34', '0x35', '0x36', '0x38', '0x39', '0x3a', '0x3c', '0x3e', '0x40', '0x41', '0x42', '0x43', '0x44', '0x45', '0x46', '0x48', '0x49', '0x4a', '0x4c', '0x4e', '0x50', '0x51', '0x52', '0x54', '0x55', '0x56', '0x58', '0x59', '0x5a', '0x5c', '0x5e', '0x60', '0x61', '0x62', '0x64', '0x65', '0x66', '0x68', '0x69', '0x6a', '0x6c', '0x6e', '0x70', '0x71', '0x72', '0x74', '0x76']
Now there is a devices 0x5e
in the list that wasn’t there before. There is no other change and devices on the I2C bus don’t function.
I noticed that the SI7021 also isn’t soldered on straight. At this point I’m assuming the AQW is defective.
There is a testpoint on the board. Do you have any advice on what I could measure to verify it?