HTU21D-F Does not obtain readings while on the I2C bus with other input devices

Hardware
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1

HTU21D-F Does not obtain readings while on the I2C bus with other input devices (4-atlas probes, 4-ezo-pmp, 1-LCD, and ADS115). If I put it on the I2C bus by itself it works fine. I can see the device address in both scenarios however I only get readings in the latter. Any idea what would cause that and how to solve it? I’m considering trying a multiplexer. The device says 3v or 5v so I don’t think the voltage is and issue. I don’t have a duplicate address situation. So I’m not sure the multiplexer will help.

2

Try experimenting by adding one device at a time until you find the offending device.

3

Thanks for the quick response, totally impressed and appreciative!! I tried one at time as advised. Now everything is reading except the ADS115. It’s I2C address shows up (49) on the same Line as the the HTU21D-F (address 40). It’s seems as if they are being treated as the same address? Although I would much rather have the HTU21D-F working I still want to figure out how to get both devices working at the same time,

4

If they have different addresses, they should be able to work together on the same I2C bus. Are you running long wire lengths or providing different voltages to the devices?

5

Everything is on 5v. I am using 6ft piece of Cat6 from the Pi in the main JB to a smaller JB with terminal blocks and all devices except the ADS115 (which is in the main JB with the Pi). The cables going from the Pi to the ADS115 are only a few inches long.