Is it possible to clear / reset the data file on the iotawatt SD card to start with a fresh datafile?
Is it possible to replace the OEM SD card with one of larger capacity to maintain larger data file, or will the updated changes to logging override that regardless of SD card size?
The next release of the firmware has tools to do that from the app, but for curent releases, you would need to delete the files manually using another computer.:
Power down the IoTaWatt
Open it up and remove the SD card
Mount the SD in another computer and delete iotawatt/iotalog.log
Reinsert the card in IoTaWatt
Restart the IoTaWatt
It will create a new log.
Because the file is open and being written frequently, you can damage the file system by deleteing while IoTaWatt is running. The new tools will close and delete the file and restart the ioTaWatt in one operation.
The current card can easily hold the maximum size datafile - 15 years. It’s explained here