Thank you for the pictures. Given your information that similar setups have worked for you over the past several years, I think these are unlikely to explain the current problems, but here are a couple things that caught our attention:
- It is not clear from your schematic what the relay is for, but I do not see any immediate problems with the connections shown there. Has that part of the circuit been the same since you started using these sensors?
- The wire colors shown in your picture are counterintuitive for the connections you are making (green, white, red, black for VIN, GND, SDA, SCL respectively, rather than red and black for VIN and GND), so it might be worth checking that these are all being wired correctly.
You mentioned earlier that you are still able to communicate with the sensors; can you explain how you confirmed that? For example, if you are using our library, have you verified that the init() function returns true?
Establishing when exactly the sensors are failing and what your system is doing at that time will probably be a critical prerequisite to understand what is going on. Is it possible for you to somehow more actively monitor some of your systems after installing new sensors to identify when failures are happening? We can also still arrange for you to send us some of your units for us to look at, although it might still be difficult for us to provide much insight without a more complete understanding of what’s going on at the time of failure.
- Patrick