Data logger - on node

[mitra42]

See Branch 110-datalogger

Data can be logged at multiple places in the architecture - the node; the local controller if present; and anything running frugal-iot-logger.

From a hardware perspective ....

• Mount SD card shield on a D1-mini or C3-pico
• Research which pins it uses, and see what that has conflicts with - see pins.md
• Find drivers for the SD and include in a system_sd.cpp
• Write interface code like the "control" that logs a set of messages to the SD card - note those messages aren't necessarily local to the node (which may also help with compatability issues with other sensors/actuators.
• Need system_fs to include
  • append(String&)
  • how much space on disk
  • exists
  • append(topicpath, payload)
    THINKING - for logger - rather than just FS
• build logger in frugal_iot.ino
• Array of IN, currently wired
• Think through advertizing or other way to hard wire inputs
• Check its subscribing
• Get date - eventually from system_rtc (waiting on card for ESP8266 but should be easy on ESP32)
• Build standard record date,value for each incoming message
• Append to file

[mitra42]

I'm working on this in branch 110-datalogger feel free to pick up some of the tasks :-)