hpsaturn / m5stickc-dcf77-hat

Basic implementation of a DCF77 receiver (hat) for the M5StickCPlus ESP32 board

M5StickC DCF77 HAT

Basic hat implementation of a DCF77 receiver on a M5StickC-Plus or compatible ESP32 devices. This firmware uses an improvement of Arduino-DCF77 library, using an event callback to improve the GUI and signal representation.

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Device

The current firmware was tested on 77.5KHZ single frequency device. It is the 4 pins version and it was bought in Aliexpress.

Wiring

M5StickC pin	DCF77 pin	Description
0	P	PON: Enable/Disable
26	T	Interrupt pin or data
3.3v	VDD	Positive (3.3v)
GND	GND	Ground / unlabeled pin

(see the photos in Thingiverse)

Usage

Some tips:

• Check the right device. Some devices has different frequencies for each country.
• Try to leave the device from away any radio or wireless interference or noise. The radio is very susceptible to noise.
• In indoors it works, but is possible that in some builds doesn't. Try in outdoors first.
• The position of the device for me was important, in horizontal is possible that it works better

Buttons:

• Left button: Power ON/Off
• M5 Button: Backlight or brightness toggle
• Right button: Unimplementened

Installation

Please install first PlatformIO open source ecosystem for IoT development compatible with Arduino IDE and its command line tools (Windows, MacOs and Linux). Also, you may need to install git in your system.

For the default board, the M5StickCPlus, only clone this and upload firmware via USB cable with a simple command:

pio run --target upload

or import the project in VSCode and build and run it.

Box

Is a basic box - hat for these devices, for example M5StickC or M5StickC-Plus, also should be work in M5CoreInk device.

Files:

Also in Thingiverse.

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Thanks to

@felmue to fix a sporadical crash.
@jcomas for the help and docs on https://t.me/esp_es
The old DCF77 library
The Seiko documentation

m5stickc-dcf77-hat's Issues

frequent crashes

Hello there,

first of all, thank you very much for this repository.

I run the code on an M5StickCPlus and while it works ok the program from time to time crashes. Is that something you've encountered as well? Just curious.

I think it might have to do with the callback functions which are called from within the interrupt and on the ESP32 there are some restrictions regarding what's allowed in an interrupt and what not. I already removed all Serial.print() statements, but maybe writing to the screen is also problematic.

BTW: when I disable the callbacks I don't see any crashes anymore.

Thanks
Felix