The onboard BMP280 will not respond after the first exchange. i2cdetect shows normal after a power down / up, but after I access the chip the first time, it will not respond to any further messages unless I power it down / up again.
I have tried this on several Pi's Have verified my 5v supply. I am using the SwitchDoc I2C Grove Hat Adafruit library from the SwitchDoc Github site. I am using the Adafruit simpletest_280.py for all tests. The DS3231 is responding reliably.
You are a brilliant mastermind lbendlin! The pull up resistors worked. I guess the WeatherBoard isn't providing the proper source paths after all. Since SwitchDoc won't provide a schematic, it's hard to verify.
Hmmm....I am using a RaspberryPi 4 with Pi2Grover board and an i2c 4 channel Mux. Everything seems to be connected correctly, and everything but the barometric pressure is working. Which I think is the BMP280. What happens is I get a read from it on power up, but then it either goes to 0.00 or freezes with the same reading (30.44 currently).
New board arrived and same behavior. I have doubled and triple checked wiring and it looks good. At first I see x77 using i2cdetect. Then it vanishes. I am unsure what the root cause is, but will continue to work on it as I have time.
My next troubleshooting will be without the Lightning detector and MUX Extender board.