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https://github.com/oliver-joos/wlan-relays
Very simple HTTP server written in MicroPython for switching ESP32 pins and connected relays via WLAN
https://github.com/oliver-joos/wlan-relays
iot-device micropython
Last synced: 2 months ago
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Very simple HTTP server written in MicroPython for switching ESP32 pins and connected relays via WLAN
- Host: GitHub
- URL: https://github.com/oliver-joos/wlan-relays
- Owner: oliver-joos
- Created: 2023-05-14T21:57:20.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2024-01-03T18:10:44.000Z (6 months ago)
- Last Synced: 2024-01-28T08:09:58.017Z (5 months ago)
- Topics: iot-device, micropython
- Language: Python
- Homepage:
- Size: 14.6 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Lists
- awesome-micropython - wlan-relays - Very simple HTTP server written in MicroPython for controlling the pins of an ESP32 board. (Libraries / Communications)
README
# WLAN Relays
This repository contains a very simple HTTP server written in
[MicroPython](https://micropython.org/) for controlling pins of an ESP32 board.
These pins can be connected to solid state relays to switch lamps for example.
## Client Example
The board will start in access-point mode. This means it provides its own WLAN
and you have to connect your computer or phone to it first. In this mode, the
board always has the **IP address 192.168.4.1**.
Set pin D22 to low using the HTTP client **curl**:
```shell
curl -v -m 3 -X POST http://192.168.4.1:7005 --data '{"pin22": false}'
```
You can connect the board to your existing WLAN by entering your WLAN SSID and
password into ``secrets.py``. In this mode, your router assigns a new IP address
to the board, which is then displayed in the web interface of most routers.
## The Hardware
**ESP32 DevKit V1** boards have WLAN hardware built-in and run with 5V and
only 50mA idle or 130mA while transmitting. Pinouts of common ESP32 boards are
[here](https://randomnerdtutorials.com/esp32-pinout-reference-gpios/).
A few hundred watts AC can be switched with a **5V DC AC solid state relay**.
Some of these can be controlled directly by 3.3V output pins. During power-up
the ESP32 pins are inputs (have high impedance but 3.3V). To keep relays off
until the pins are actively controlled as outputs you can use
**Low Level Trigger variants** (>1V ⇒ off, <1V ⇒ on).
### Additional hints
* To reset a ESP32 DevKit V1 board press **button "EN"**
* To suppress boot messages pull-down **Pin D15 to GND** with a 10k resistor
(helps to avoid problems with terminal tools)
* Pins >=34 are **inputs only!** (no output on D34, D35)
## The Software
The following tutorial works on a Linux Mint 21.x or similar Debian-based Linux
like Ubuntu. You can run Linux Mint directly from a Live USB stick without
installing it on your computer.
Install the **ESP-IDF 5.0.4** build tools (**only needed once!**):
```shell
sudo apt update
sudo apt install git wget flex bison gperf python3 python3-venv cmake ninja-build ccache libffi-dev libssl-dev dfu-util libusb-1.0-0
sudo apt remove brltty # stop brltty from stealing /dev/ttyUSBx
mkdir -p ~/esp && cd ~/esp
git clone -b v5.0.4 --recursive https://github.com/espressif/esp-idf.git
cd esp-idf
./install.sh esp32
sudo adduser $USER dialout # allow access to USB serial devices
# ... and then logout and login again!
```
Download this project and prepare MicroPython for ESP32 (**only needed once!**):
```shell
mkdir -p ~/git && cd ~/git
git clone https://github.com/oliver-joos/wlan-relays.git
cd wlan-relays
git submodule update --init micropython/
make -C micropython/mpy-cross/
make -C micropython/ports/esp32/ submodules
```
Setup your terminal (**needed once per session!**):
```shell
source ~/esp/esp-idf/export.sh
export ESPPORT=/dev/ttyUSB0 # or /dev/ttyACM0 for CH9102X USB ICs
export ESPBAUD=921600
```
Build and deploy the MicroPython firmware image:
```shell
make -C micropython/ports/esp32/ clean # only after changes in micropython/
make -C micropython/ports/esp32/ -j all
make -C micropython/ports/esp32/ PORT=$ESPPORT erase # only for empty boards
make -C micropython/ports/esp32/ PORT=$ESPPORT deploy
```
Copy Python files to your board (**overwrites existing files!**):
```shell
./micropython/tools/mpremote/mpremote.py fs cp *.py :/
```
Now press the reset button on your board!
To see log messages or soft-reset the board you can use the MicroPython REPL interface:
```shell
./micropython/tools/mpremote/mpremote.py # connect to REPL
# press Ctrl+C to abort the application
# press Ctrl+D to soft-reset the system
# press Ctrl+X to exit the mpremote tool
```