You find here problems and solutions collected by users. I spend some time to write this documentation. Please take your time to read it before you open a new issue.
If you can't find the solution for your problem here and not in the existing Issues you can open a new issue. But please consider the following topics:
- You should have a basic understanding how to use an ESP8266. That includes the usage of an IDE for programming, compile, flash, OTA and log output via the serial terminal.
- You should have a basic understanding of the MQTT protocol and how to setup a MQTT broker
There are great descriptions in the WWW related to the topics above. Please use your preferred search engine.
If you open a new issue, please consider the following topics:
- Use a use a meaningful title, so that the next user with a similar problem can recognize it
- Which program version do you use?
- Add the exact name of your AC indoor unit, e.g. SRK 35 ZS-S
- MHI-AC-Ctrl outputs some basic status information via the serial terminal (115000 Baud). Please use it for your first analysis and upload it together with a new Issue
- Sometimes you will be asked to generate a detailed log of the SPI waveforms. This is done via the SPI-logger. Please don't copy the log output into the Issue description, instead attach it to the Issue. For finding a solution for your problem, you should use the log output via the serial monitor (115000 Baud).
MHI-AC-Ctrl doesn't support all functions of the infrared remote control. This is because some functions are not reflected by the SPI payload:
- "auto" for the fan is not supported, only 1, 2, 3,4 for fan are supported
- Vanes left/right is not supported
- Vanes up/down is supported, but with the limitation that if the last command was issued by the IR RC, then the vanes up/down status is not visible in MHI-AC-Ctrl
This should be considered especially when you use the IR RC in parallel to MHI-AC-Ctrl.
For a periodic crash there are different causes possible:
During boot the frequency of the SPI pins are checked. This is very helpful to identify SPI signal connection problems. Following values are expected:
- SCK frequency > 3000 Hz
- MOSI frequency < SCK frequency (usually ~ 500 Hz)
- MISO frequency ~ 0 Hz (usually 0Hz)
If you see other values, please re-check
- the connection between the MHI-AC-Ctrl board and your AC
- that there is no short between the three signals
If MISO frequency>10Hz the program will stop and reboot. This prevents damage of your board or AC because there was a signal detected on the MISO pin which should be an output during normal operation.
Typical faults seen in the past:
- SCK frequency = 0Hz => SCK pin not connected
- SCK frequency < MOSI frequency => SCK and MOSI pins swapped
- MISO frequency = SCK frequency => MISO and SCK pins shorted
There was a bug introduced in PubSubClient version 2.8.0, please use v2.7.0.
The HOSTNAME specified in support.h is used as WiFi hostname, MQTT hostname and OTA hostname. In case that you use more than one MHI-AC-Ctrl, e.g. in a multi-split configuration, you have to use unique HOSTNAME to every PCB.
Different root causes are possible:
Please check this section
The MQTT path for receiving the status is different from the MQTT path for setting values. Re-check that you use the set-path described in SW-Configuration.md. Please pay attention to the case sensitivity.
That is no bug, but a restriction because the SPI unfortunately doesn't provide the Vanes status when the IR remote control was used for the last command.
That is no bug, but a restriction because the SPI unfortunately doesn't support 'auto' for the Fan.
With some ACs the SPI connection is fragile because of a different timing. However, this does not appear to be critical and is usually not noticed by the user.
This effect occurs with some AC models. The cause is unclear.
I believe this is a general OTA problem, not related to MHI-AC-Ctrl. I made good experience using espota.py instead of the Arduino IDE for OTA.