Request for DFPlayer Mini Driver/Library for ESP8266 with Moddable SDK

[akbaraditamasp]

Hi, Moddable SDK community!

I’m working on a project with ESP8266 and the DFPlayer Mini module, aiming to play MP3 files stored on an SD card. I’ve tried implementing communication using bit-banged serial, but it’s been quite challenging and not reliable.

Before investing more time in a custom solution, I wanted to ask:

Is there an existing driver or library for DFPlayer Mini that works with the Moddable SDK?
If not, has anyone successfully interfaced with DFPlayer Mini and could share a working example?
A prebuilt driver or guidance on how to efficiently handle communication with this module in JavaScript (via Moddable SDK) would be immensely helpful.

Thank you for any pointers or support!

[phoddie]

Welcome!

I'm not familiar with the DFPlayer Mini module. You mention "bit-banged serial." Is there a reason that you are not just using the serial driver? The ECMA-419 Serial IO module is available for ESP8266. The standard itself is a little challenging to read, but there are a couple of examples in this repository that should get you started: continuouswrite and echo. I'm happy to try to answer any questions you may have about that.

[akbaraditamasp]

I finally decided to move the pins for the DFPlayer. Can I change the Serial to use specific pins? I didn't see any examples of this at all.

[phoddie]

ESP8266 has two fixed serial ports, as noted above:

There are two serial ports on an ESP8266. The first is GPIO 1 & 3.... The second serial port is transmit only, on GPIO 2.

The pins cannot be changed: they are fixed in hardware. Here's the pinout diagram that shows them.

You select the transmit and receive pins in the constructor options object as documented in the link to ECMA-419 above:

let serial = new device.io.Serial({
	...device.Serial.default,
	transmit: 1,
	receive: 3,
	baud: 115200,
	format: "buffer",
	// etc...
});

[akbaraditamasp]

Is there no library to perform something like SoftwareSerial in Arduino?

[akbaraditamasp]

Finally, it works! It turns out that I needed to include onReadable. It seems to be required to forward commands sent to the Serial. Perhaps I wasn't careful enough when reading the documentation.

const serial = new device.io.Serial({
  ...device.Serial.default,
  baud: 9600,
  format: "number",
  // This part solved my problem
  onReadable: function (count) {
    while (count--) this.write(this.read());
  },
});

I might release the DFPlayer library soon after this. Thank you!