Undocumented error code MPC

[mvn23]

While playing around with the new firmware v5.0 I ran into the following:

Code: Select all

command: C2=9.999
reponse: MPC

Unfortunately I can't find this error code anywhere in the docs.
I'm guessing it has something to do with the float parsing (C2=9.99 is accepted without issues) but I would like to get some more info on this.
Also, if anyone is aware of any more such codes, sharing is appreciated

[hvxl]

MPC is not an error code. The letters represent the settings for LEDs D,E, and F. You get this output because the result of the subroutine to parse a floating point number is incorrectly interpreted as a pointer to an error code in EEPROM. Because you used 9.999, you get the data at offset 9. If you try 4.999, you get all LEDs: "L=FXOMPC". And 15.999 returns "A=OpenTherm Gateway 5.0". Needless to say, this is another bug.

I've created a test for both of your findings in the test suite. So they will be verified before I release a new firmware version in the future. I've also added a test for OT=-0.004, which should round up to 0.00. At least that one already works correctly.

It looks like you are stress-testing the firmware. Do let me know if you find more bugs.

[mvn23]

Haha that's awesome! Thanks for the info. I already added an 'MPC' error code in my dev version of pyotgw guess I'll have to remove it again.
I'm trying to cover all of the more or less reasonable user inputs for the pyotgw update. If I find anything else I will of course update on this forum.