@Robert, glad to see that you are making use of the current system to log flow rate. Here is how the log data is formatted: each entry records the [program_index, station_index, duration, time_stamp]. When program_index is non-zero, this is a normal log record storing a standard sprinkler event. When program_index is 0, this is a special log record, and the station_index becomes the name of the event. The currently supported events are defined here:
https://github.com/OpenSprinkler/OpenSprinklerGen2/blob/master/main.cpp#L736
there are rain sensor, rain delay, and water level events. In the future we can add an additional event such as “fl” (flow), and duration would become the numerical value of the flow measurement.