Voltmeter sender and remote display
This project started as a way to keep tabs on the battery of a rarely used old car parked in the garage. There are two parts:
- The sender measure voltage and responds to http request via the home wifi OR its own AP. This is read with any wifi capable browser, phone etc. Sender needs an ESP with an Analogue pin. I use Wemos D2.
- The (optional) receiver that uses a 1" OLED display to show current voltage and then go back to sleep. An ESP-01 is perfect for this job. If measuring big batteries (e.g. car/boat/caravan) the sender could also be powered from the measured supply.
Configuration is needed to set the matching wifi networks. Options are available to set the Name of the voltmeter being read.
