I currently am powering a 5V sensor (SPS30) using the 3.3V out line of the particle boron and buck converter to 5V. I am then using a logic level shifter (BOB-12009) to shift the logic signals from 5V to 3.3V to comply with the borons i2c line requirements. The issue is that I continue to get a bus error on the i2c line (red bllnking light) when I try this configuration. Has anyone seen this issue or have any insight on what the issue could be?
3.3V sensors are working normally and I have verified there are no issues with the line at the moment.
Could you be more specific about the actual red blinking pattern you see?
Can you also provide us with a simple test code that exhibits this behaviour?
Can the sensor be found on the I2C bus via a I2C scan like the one shown here https://docs.particle.io/datasheets/app-notes/an014-tracker-i2c-scanner/ (don’t mind that this is targeted at the Tracker One - it will work with the Boron just the same)
What ScruffR said. Also, a diagram of your circuit would be helpful.
The BOB-12009 does not have I2C pull-ups on the board, so on the Boron side you need 2.2K to 10K pull-ups from D0 to 3V3 and D1 to 3V3.
On the sensor side you may need pull-ups to 5V, it depends whether your SPS30 breakout has them on the breakout board or not. If you have bare sensor, it will likely need pull-ups.
Having the wrong pull-ups usually just causes a failure to communicate. The most common cause of a SOS fault is forgetting to call Wire.begin() before using I2C.
