meshtastic
[Bug]: BME280 does not get initialized on RAK11300
Category
Other
Hardware
Rak11310
Firmware Version
2.5.11.8e2a3e5
Description
I've added a BME280 to the RAK11300 on the RAK19003 Mini Base Board. BMP280 is recognized but does not initialize. The BME280 module has been tested with RAK4631 and works fine.
Relevant log output
INFO | ??:??:?? 2 Scan for i2c devices...
DEBUG | ??:??:?? 2 Scan for I2C devices on port 1
DEBUG | ??:??:?? 2 I2C device found at address 0x76
DEBUG | ??:??:?? 2 Wire.available() = 0
DEBUG | ??:??:?? 2 Wire.available() = 0
INFO | ??:??:?? 2 BMP-280 sensor found at address 0x76
INFO | ??:??:?? 2 1 I2C devices found
...
INFO | ??:??:?? 13 [EnvironmentTelemetry] Environment Telemetry: init
INFO | ??:??:?? 13 [EnvironmentTelemetry] Init sensor: BMP280
WARN | ??:??:?? 13 [EnvironmentTelemetry] Could not connect to detected BMP280 sensor. Remove from nodeTelemetrySensorsMap.
I am seeing the same problem as you. I have a RAK1906 (Environment Sensor BOSCH BME680) with a RAK11310 (Raspberry Pi RP2040 Core Module for LoRaWAN with LoRa SX1262) on a RAK19007 (WisBlock Base Board 2nd Gen). The module is in slot B and the environment module was enabled with the Python CLI (meshtastic --set telemetry.environment_measurement_enabled true). The version is firmware-rak11310-2.5.11.8e2a3e5.
To rule out a hardware problem I loaded a Raspberry Pi Pico CircuitPython image to the RAK11310 and put together a basic program to test the RAK1906. As can be seen from the screenshot the hardware works OK. I also tested a generic SSD1306 OLED display using tutorial code from Adafruit learn and that also worked fine.
I started poking into this a little more and I think the entry point to the problem is here: https://github.com/meshtastic/firmware/blob/8e2a3e5728bc997449c7507be76249b7a90166a6/src/detect/ScanI2CTwoWire.cpp#L264
The first registerValue that is looking at address 0xD0 (chip id) is getting returned is 0x00 so its dropping into the default case.
I hooked up a logic analyzer to BOTH I2C ports on the RAK IO expanded wisblock and I see some strange behavior... I see the boot scan but when my I2C device ACK the RP2040 probes the device again on the other I2C port!
Confirming that if "0xD0 (chip id) is getting returned is 0x00" a BME280 will be detected as a BMP280 and not work. Do you know why the chip ID is not working correctly? Does it work correctly on your CircuitPython image?
https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme280-ds002.pdf
I am encountering the same issue with the RAKwireless RAK19007 WisBlock Base Board (2nd Gen), RAK11310 (RP2040), and RAK1906 (BME680) combination. I even reverted to firmware version 2.3.9.f06c56a, but the problem persists.
Can confirm that this is fixed with 2.6. RAK11310 (RP2040) and RAK1906 (BME680) combination is working! I had the almost same issue with the RAKwireless RAK1902 (LPS22HB) and RAK11310 (RP2040) and that combination is also working again. :)