The SQL Lite idea is not bad and not too difficult to implement; I thought of it a bit different by buffering requests on memory like a queue (a FIFO). But SQL Lite could be a good alternative that brings backup as bonus.
To test this, do you know if I could have two programs querying the inverter at the same time without messing things up?
No and yes!
No, serial ports are not meant to have concurrent access.
Yes, it will work but sometimes it may conflict and fail readings on both sides. I do this to test sometimes but you can try reading at same time the other program is doing its stuff. In this case both programs will result in invalid readings. For sporadic test it “ok” but for long running it is not good idea.
When you have one datasource like the inverter and want many consumers of that data, the best approach is to use a proxy agent in the middle. Most IoT home projects today uses MQTT protocol to buffer between datasources and data consumers. It would be simple to break the code into “inverter reader” that reads inverter and post data to somewhere (MQTT or SQLite or Redis) and another program that subscribe to that data, process and send it to another place. In fact, this architecture (using MQTT or Redis) would allow for fun things like real time dashboard, alarms, etc…
(but the other script works)
jrbenito:
