Hi all,
I have 3 SparkFun BMI270 Qwiic breakout units, purchased together from Mouser Electronics, and none of them will initialize over I2C.
Setup:
- Tested on 2 different host boards: DFRobot FireBeetle ESP32 (DFR0478) and Seeed XIAO ESP32C3
- Powered via 3.3V (regulated 3V3 output on each board), standard Qwiic cable
- PWR LED on each breakout lights up fine
Symptoms:
- SparkFun BMI270 Arduino Library’s
beginI2C() never succeeds
- A generic I2C address scanner finds zero devices on any unit, on either board
- Direct register reads (writing to CHIP_ID at 0x00, then reading) return timeout (error 5) or error 4 depending on transaction style, never valid data
Given this fails identically across all 3 units and both host boards, I’m skeptical it’s three coincidental hardware failures. Has anyone seen this pattern before, or is there a known BMI270-specific I2C quirk (power-on sequence, required soft-reset, timing requirement) that would explain consistent failure at the basic register-read level?
Thanks!
Can you test without the breadboard? Just wire the 4 qwiic wires directly to the MCU and see if anything changes (apologies if you already have, or if you don’t have a female qwiic cable/wires available)
If you disconnect the BMI and try another i2c sensor is it detected/working as aexpected?
Hello, thanks for the prompt reply!
It works with an MPU6500 and im able to get the reading. I have also tested with the female side connected directly to the firebeetle and it does not work (photo attached)
The qwiic connector shouldn’t be faulty as well as i have tested it with the exposed board solder.
Hi, after investigating further i found that the connected SDA & SCL lines reads 2.7V & 0.5V respectively. These are the same on both my ESP boards [Firebeetle DFR0478 & Xiao ESP32C3], ive also tried reading with direct connection and i get the same reading as well. Im unsure as to whether these are the correct readings im suppose to get as im of the knowledge that it should be pulled up to 3.3V.
*Correction: Other than the board above, I have another board that reads only 0.5V at the VCC and one more that does not have the power light but reads 3.3V on VCC and 2.7V on both SDA & SCL, so its all inconsistent..
