ERROR: I2C read error: -2

Hardware
1

I’ve been using the Env Tail to grab temperature readings from an Imp, and I noticed it was just throwing errors, so I did a quick search and found this thread here:

https://discourse.electricimp.com/t/env-tail-i2c-error-2-transmit-select-error/3601

Looks like maybe I’m having the same issue. My exact error message was:

|2019-07-13T00:17:56.463 +00:00|[Status]|Device disconnected|
|---|---|---|
|2019-07-13T00:17:56.550 +00:00|[Status]|Device connected|
|2019-07-13T00:17:56.622 +00:00|[Device]|ERROR: I2C read error: -2|
|2019-07-13T00:17:56.629 +00:00|[Device]|ERROR: the index '0' does not exist|
|2019-07-13T00:17:56.629 +00:00|[Device]|ERROR:   in enable ...tricimp#lps25h.class.nut#1.0.0:87|
|2019-07-13T00:17:56.629 +00:00|[Device]|ERROR:   from init ...tricimp#lps25h.class.nut#1.0.0:47|
|2019-07-13T00:17:56.629 +00:00|[Device]|ERROR:   from constructor ...tricimp#lps25h.class.nut#1.0.0:42|
|2019-07-13T00:17:56.629 +00:00|[Device]|ERROR:   from main device_code:16|

I had another Env Tail, and I swapped it onto the Imp that was giving me trouble, and now it’s working. I guess the tail is kaput?

3

Yes, possibly the tail is broken if another one works. Anything you can see on the tail itself which implies a short or something?

TRANSMIT_SELECT_ERROR generally means one of SCL or SDA are stuck low and the imp can’t get on the i2c bus.

4

Yeah, nothing I could see (or smell! :smiley:) on it that made it appear like it had shorted. I’ll give it a closer second look later today.