Detect dummy temperature sensor values

[lincomatic]

One of my EVSEs only has a MCP9808. As such, the only valid temperature is TEMP2. Therefore, my displayed temperature is garbage:

Would it be possible to test the temperatures for negative values in sequence, and use the first positive value encountered?

[glynhudson]

The issue with looking for the first non negative value is it's possible for the temperature inside the openevse to be negative in very cold environments.

Is the value -256 a preset 'dummy' value for when no sensor is connected? Could we look for this instead?

[lincomatic]

It is, but unfortunately, older versions of the firmware returned zero or 230. I didn’t discover this until recently.. someone else wrote the code. I changed it in D4.10.0

vD4.10.0 20170817 SCL

• change TMP007 temperature was showing up as 230 when not installed.
• also, temperature for other devices was 0 when not installed, but 0 is a valid temperature -> change all default temps to TEMPERATURE_NOT_INSTALLED (currently -2560) -> bump up RAPI version to 4.0.1

From: Glyn Hudson [mailto:[email protected]] Sent: Monday, February 12, 2018 3:47 PM To: OpenEVSE/ESP8266_WiFi_v2.x [email protected] Cc: lincomatic [email protected]; Author [email protected] Subject: Re: [OpenEVSE/ESP8266_WiFi_v2.x] negative temperature (#151)

The issue with looking for the first non negative value is it's possible for the temperature inside the openevse to be negative in very cold environments.

Is the value -256 a preset 'dummy' value for when no sensor is connected? Could we look for this instead?