Heizungssteuerung mit MicroPython auf dem ESP32 – Teil 1

What is this part about?

In this part you will learn:

How to install MicroPython on the ESP32.
How to connect to WiFi. We will revise this connection later so that we can configure it via the web interface.

Installation of MicroPython on the ESP32

How to install MicroPython and the required tools on the (Windows) PC, I have in this tutorial already described. That's why I'll only briefly summarize the steps here:

After the tools (esptool, rshell) are installed on the PC, we delete the memory of the ESP32

bash view raw

> esptool.py --port COM5 erase_flash

and then flash the current one MicroPython image on the ESP32 (use ESP-IDF v3.x, I had problems with v4.x):

bash view raw

> esptool.py --chip esp32 --port COM5 write_flash -z 0x1000 ./esp32-idf3-20210202-v1.14.bin

To test whether everything really worked, we connect with rshell on the ESP32:

bash view raw

> rshell -p COM5
Using buffer-size of 32
Connecting to COM5 (buffer-size 32)...
Trying to connect to REPL . connected
Testing if ubinascii.unhexlify exists ... Y
Retrieving root directories ... /boot.py/
Setting time ... Feb 11, 2021 22:00:58
Evaluating board_name ... pyboard
Retrieving time epoch ... Jan 01, 2000
Welcome to rshell. Use the exit command to exit rshell.

If your output looks something like this and shows no errors, everything worked.

Establish a WiFi connection

Now that MicroPython is installed, we can begin the actual programming.

First we put the file main.py with the following content:

main.py view raw

import network
import time

wlan = network.WLAN(network.STA_IF)
wlan.active(True)
# Set DHCP host name to recognize the device in your router
wlan.config(dhcp_hostname="Heater")
# Replace your SSID and password
wlan.connect("<SSID>", "<password>")

while not wlan.isconnected():
    time.sleep(1)

print("WiFi connected")

We then copy this file to the ESP32 (rshell is still running), then switch to the REPL and restart the ESP32 with CTRL + D:

bash view raw

> cp main.py /pyboard
> repl
[CTRL+D]
MPY: soft reboot
Wifi connected
MicroPython v1.13 on 2020-09-02; ESP32 module with ESP32
Type "help()" for more information.
>>>

I've written a small logger module with which I can display log outputs more comfortably and, if necessary, have them sent to a SYSLOG server later. You can get this module download here and then copy it to the ESP32 or alternatively with upip to install:

REPL view raw

import upip
upip.install("micropython-eydam-prototyping-logging")

In the main.py we then import the module, initialize the logger and replace the print output.

main.py view raw

import network
import time
import ep_logging

wlan = network.WLAN(network.STA_IF)
wlan.active(True)
# Set DHCP host name to recognize the device in your router
wlan.config(dhcp_hostname="Heater")
# Replace your SSID and password
wlan.connect("<SSID>", "<password>")

while not wlan.isconnected():
    time.sleep(1)

logger = ep_logging.colored_logger(appname="main")
logger.notice("WiFi connected")

We'll change a few things here later, but it should be enough for now. It continues with the HTTP server in the second part.

Heating control with MicroPython on the ESP32 - Part 1

Tobias Eydam

What is this part about?

Installation of MicroPython on the ESP32

Establish a WiFi connection

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Heating control with MicroPython on the ESP32 - Part 1

Tobias Eydam

What is this part about?

Installation of MicroPython on the ESP32

Establish a WiFi connection

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