PCF8574 I2C DIO extension

The PCF8574 currently adds 8 additional relays to the firmware. With different jumper settings up to 32 relays will work ou-of-the-boy with the Tasmota firmware. You can handle up to 64 relays but then you have to change the type of the typedef power_t inside the code. This needs to be uint64 to support the 64 digits. Please be aware that some logging will not work with 64bit variables.

After wire the PCF to the I2C bus and defining the SCL and SDA in the configuration page you should see in the serial log that at least 1 PCF8574 board was found. Then you can go to the configuration page on the web and find a NEW configuration page for the PCF.

Relays can be inverted and changed from input to output. The Input is currently not working. This is a coming soon enhancement. Inputs will be served as SWITCHES.

Friendlynames and some other special options are only available on the first 4 relays. Changing Code parameters during compile can change this. relays on GPIO are always BEFORE the PCF relays. A reorder can happen is adding/removing GPIO replays.