A range of discussions and system-sized projects that relate to the dMeccano experiments.
Repair broken / unwritable ESPs
This has happened to me a couple of times and I’ll write it here as much to keep it in memory !
Symptom: ESP suddenly refuses to update from Arduino or update SPIFFS / LittleFS. In my experience this shows up as an MD5 error after any upload. (Read the article)
Differing ESP32 display boards
Development boards with TFT displays are effective and powerful IOT tools. Here are a few notes gained from working with two similar units, and the issues raised in moving applications between them.
(Read the article)
There are several ways to control the operation of system daemons – programs that run relentlessly and unattended. Here we’ll use systemd and its management tool systemctl.
(Read the article)
MQTT : Why and How
MQTT is a protocol for message handling across networks. An MQTT server or Broker allows multiple Clients to send and receive short messages while they are attached (Subscribed).
(Read the article)
It turns out that the “Sungrow” inverters use a version of modbus standards that can be interrogated via TCP/IP. This article discusses the practicalities of getting inverter data and making use of it with MQTT and SQL database. The outcome is to try and get detailed and reliable graphical reporting.
(Read the article)
ePaper presents a different way of thinking about presenting data.
These notes come as I experiment with Lilygo EDP47.
This impressive device costs less than $50 AUD and features:
- ESP32 microcontroller
- Wifi
- Battery management and housing
- 4.7inch ePaper display
- Four pushbuttons