DFRobot mini with pause for podcasts

For an index to all my stories click this text.

In a previous story I wrote how to use a DFRobot Mini MP3 player. The player is attached to a Raspberry Pi Pico with 5 keys. The key's functions are next song, previous song, volume up, volume down and reset. You can read that story here: 
https://lucstechblog.blogspot.com/2026/07/dfrobot-mini-mp3-with-micropython.html

There are however some more commands you can issue to the MP3 player. And while using it in real life I realized I do miss these commands. So I made some adjustments to the previous design.

Pause and Resume.

The previous design had a reset button. That reset the Pico and the program started fresh making the MP3 player start playing from the first song again.

I am however a frequent podcast listener.
And when listening something urgent happens: the phone rings, the doorbell rings etc.
Stop playing the podcast is annoying as you then have to start all over again. Not a problem for a song of a few minutes but annoying when listening to a podcast of an hour or so.

Luckily the DFRobot MP3 player has a pause function (music.pause()) and a resume function (music.resume()). Pause indeed pauses the player and resume neatly starts where the player was set at pause.
So I adapted the design an added a Pause and resume button.

I also rewired the reset button to another pin and altered the software so that it makes the player sop playing. Pressing any button (except the volume buttons) then restarts the player at the next song in line.

Breadboard.

You can find the description in the previous story. I just mention the 3 new buttons here.
The pause and resume button are wired to GPI14 and GPIO15.
The stop button is wired to GPIO11.

As mentioned in the previous story: watch out which pins you use. Pins GPIO12 and GPIO13 are wired to UART0. And UART0 communicates with the DFRobot Mini MP3 player. So pressing a button attached to one of these pins interferes with the Uart communication and makes the player behave strangely.

Please note that the USB power line is only connected to the DFRobot Mini player. It is not connected to the Pico. The GND lines are connected to the Pico and to the player.

The MicroPython program.

Because 1 button is rewired and 2 new buttons are added as wel extra functionality being added the software needs to be adapted. Here is the new program in full.

from dfplayermini import Player
from time import sleep
import machine

vol = 20

butstop   = machine.Pin(11, machine.Pin.IN)

butpause  = machine.Pin(15, machine.Pin.IN)
butresume = machine.Pin(14, machine.Pin.IN)

butnext   = machine.Pin(18, machine.Pin.IN)
butprev   = machine.Pin(19, machine.Pin.IN)
butvolup  = machine.Pin(20, machine.Pin.IN)
butvoldwn = machine.Pin(21, machine.Pin.IN)

busypin = machine.Pin(22, machine.Pin.IN)

txpin = machine.Pin(0)
rxpin = machine.Pin(1, machine.Pin.IN)
music = Player(pin_TX=txpin, pin_RX=rxpin)

stop = False
pause = False

sleep(.2)

music.stop()
sleep(.2)

music.volume(vol)
sleep(.2)
music.play(1)
sleep(2)

while True:
    if butpause.value() == 0:
        print("pause")
        pause = True
        music.pause()
        sleep(.5)
    if butresume.value() == 0:
        print("resume")
        pause = False
        music.resume()
        sleep(.5)
    if butstop.value() == 0:
        print("stop")
        music.stop()
        stop = not stop
        sleep(.5)
    if busypin.value() == 1 and stop == False and pause == False:
        music.play('next')
        sleep(.4)
    if (butnext.value()==0):
        music.stop()
        sleep(.5)
        print ("next number")
        music.play('next')
        sleep(.5)
    if (butprev.value()==0):
        music.stop()
        sleep(.5)
        print ("previous number")
        music.play('prev')
        sleep(.5)
    if (butvolup.value()==0):
        vol = vol + 1
        print ("Volume : ",vol)
        music.volume(vol)
        sleep(.2)
    if (butvoldwn.value()==0):
        vol = vol - 1
        print ("Volume : ",vol)
        music.volume(vol)
        sleep(.2)

Nothing special in this program except this part in the while loop:

    if busypin.value() == 1 and stop == False and pause == False:
        music.play('next')
        sleep(.4)

When the player has played one song it normally stops. The busy pin is LOW when the player plays and gets HIGH when the player stops. This is handled in a different part of the program and already discussed in the previous story.

But we do not want the player to automatically play the next song if the stop and pause buttons have been pressed. And that is handled here.

Copy the program into Thonny's editor and save it in your Pico's memory. If you did not follow the previous story then do so now because it showed where to get the required library.

If you do not have a clue about what Thonny is, how to install MicroPython or how to install libraries please consider buying one of my books, about the Raspberry Pi Pico, listed below.

That's all for now.

Till next time
have fun

Luc Volders

DFRobot mini MP3 with MicroPython

For an index to all my stories click this text.

Portable MP3 players where once THE thing to have. Now they are getting obsolete because (almost) everyone has a handheld computer (called a smartphone) that is perfectly capable of doing the job. However, sometimes you want a simple music player that does the job. And that's exactly what we are going to build.

DFRobot DFPlayer

DFRobot is an US brand that makes some neat gadgets. And the most well-known is the DFRobot DFPlayer. It is a small MP3 player that has an amplifier on board so you can attach a loudspeker for direct results. The MP3 files are stored on a SD card and therefore there is an SD card reader on board.

The board has an original price of about 5 USD but clones (which are 100% copies) can be bought from our Chinese friends for about 1.50 USD.

In 2019 I wrote a small story on how to use this MP3 player with just two buttons. The functionality was limited. Pressing the first button took you to the next song. The other button switched to the previous song. You can find that story here:
https://lucstechblog.blogspot.com/2019/05/mp3-player-stand-alone.html

In 2022 I revisited the DFRobot MP3 player and wrote a story on how you could control it from a website. That sory attached an ESP8266 or ESP32 to the DFRobot MP3 player. It had however the same limited functionality as the story with the manual control. You can read that story here:
https://lucstechblog.blogspot.com/2019/10/web-controlled-mp3-player.html

More control.

The previous two stories used the DFRobot MP3 player's IO pins to control the player. And they only offer next song, previous song functionality. There are however a lot more possibilities.
To use these extra functions you need to send commands over a serial interface (UART). And that is a lot easier as you think.

There is a nice MicroPython library that makes it possible to control almost all functions of this player. You can find that library here:
https://github.com/lavron/micropython-dfplayermini

If you do not know how to install MicroPython libraries please consider buying one of my books describing the use of Micropython with the Raspberry Pi Pico. You can find them here:

Click here to open a link on Amazon to buy my books

This library offers the following controls:

music.play(x)                            plays track x from the SD card
music.play('next')                    play the next track. If the just played track was the last
                                                       on the SD card the player will play the first track.
music.play('prev')                    Play the previous track. If there is no previous track
                                                       then the player will play the last track on the SD card.
music.stop()                               stops playing music
music.volume(x)                       sets the volume to x where x is a value fom 0 to 40
music.pause()                            stops playing
music.resume()                         starts playing where pause left
music.loop_track(                    store a track number
music.loop()                               keeps repeating the stored track
music.loop_disable()               stops repeating the track
music.fadeout(fadeout_ms)  slowly turns the volume down and stops playing

All these commands must be given over the UART lines.

The DFRobot MP3 player's pins.

The DFRobot MP3 player is a small module with 16 pins. It is breadboard friendly. Let us have a look at the pins we are going to use in this project.

VCC
Obviously this is the power line. The module needs 3.2 till 5V. I supply the power through a separate 5V USB wall plug. The 5V is connected to the module but NOT to the Raspberry Pi Pico.

GND
This is the GND line and is connected to the wall plug and the Pico.

RX
This is the UART receive line and will get connected to the Pico's TX line

TX
This is the UART transmit line and will get connected to the Pico's RX line

SPK_1 and SPK_2
Attach a speaker to these lines for playing the audio. The lines give a mono signal.
The DFRobot Mp3 player has a build-in amplifier and can run a speaker up to 3 Watt.

DAC_R and DAC_L
The DFRobot MP3 player has a build in DAC. We can attach these lines to the left and right entrances of an amplifier.

BUSY
The DFRobot mini MP3 player has a build-in led. That led is on while a sound track is playing. At the same time the BUSY pin gives a low signal. When the sound track finishes the player stops and the line gets high.

The importance of the BUSY line.

If you give the command to play a song (track) then the DFRobot puts the BUSY pin in a LOW state. Then the song finishes and the player stops. The BUSY line will get HIGH. And nothing happens further.

This is often not what we would like to happen. Most of the time we want the player to automatic play the next song.
So what we have to do is to test if the BUSY line gets HIGH and if so send the command music.play('next')

But beware !!!
If you add a stop button and give the command music.stop() the player will stop playing but the BUSY line will get HIGH. So if you do not take care of that the software will immediately send the command music.play("next') and the next track will start playing.
If you intentionally will skip to the next song (track) just press the music.play('next") button.

The same goes for a button that pauses the player. When at pause the Busy line will get HIGH and the software will automatically go on to play the next song. So take care of that in the software if you have a pause and resume button.

The breadboard setup.

I have used two half breadboards but things could easily be build on a full breadboard.

At the top there is a USB plug. In earlier projects I used a breadboard USB adapter to connect a USB power plug to my breadboard. Nowadays I use my own printed USB connector for this. That is not because they are a lot cheaper but because I always seem to miss the breadboard connectors when I need them. The VCC is connected to the DFRobot VCC line but NOT to the Pico. The GND line is connected to the DFRobot GND line and to the Pico's GND line. Here is the link to the story about this and the STL files if you want to print some yourself:
https://lucstechblog.blogspot.com/2025/03/print-your-own-usb-connector.html

Please make sure you do NOT connect the VSS line of the Pico to the VCC of the USB connector. If you do and you power your Pico from your computer you might damage the Pico and your computer beyond repair.

To the left at the top there is a speaker. It is just a speaker so not a computer speaker which has an amplifier in it. You can use earplugs or an headphone if you do not have a speaker at hand.
The speaker is connected to the SPK_1 and SPK_2 pins. So it is a mono signal.

The TX line of the DFRobot mini player is connected to pin GP1 of the Pico which is UART0 pin RX. The RX line of the DFRobot mini player is connected to pin GP0 of the Pico which is UART0 TX. So TX and RX are crossed.

The VCC line of the DFRobot is connected to the USB connector VCC and the GND.

Next there are 5 buttons at the bottom breadboard. Each button has a pull-up resistor of 10K and the first 4 buttons are connected to the Pico's pins 18,19,20 and 21. These are the buttons that choose next song, previous song, volume up and volume down.
The fifth button is connected to the Pico's pin 30 which is the reset button.

Beware of the pins

When I started testing I tought my Pico was broken. I had connected the next song and previous song buttons to the Pico pins 16 and 17. And the most strange things happened. The player would play random songs.

Then it occured to me that those pins are also used as UART0 pins.
So whenever I pushed a button I also gave a pulse on the UART pin of the DFRobot player !!

So when using UART0 you can not use pins GP16, GP17 but also not GP12 and GP13.

You can attach the DFRobot player to UART1 (GP4 and GP5) but then you can not use GP8 and GP9. To do so however you would need to alter the library which I do not recommend.

The MicroPython program

from dfplayermini import Player
from time import sleep
import machine

vol = 20

butnext   = machine.Pin(18, machine.Pin.IN)
butprev   = machine.Pin(19, machine.Pin.IN)
butvolup  = machine.Pin(20, machine.Pin.IN)
butvoldwn = machine.Pin(21, machine.Pin.IN)

busypin = machine.Pin(22, machine.Pin.IN)

txpin = machine.Pin(0)
rxpin = machine.Pin(1, machine.Pin.IN)
music = Player(pin_TX=txpin, pin_RX=rxpin)

sleep(.2)

music.stop()
sleep(.2)

music.volume(vol)
sleep(.2)
music.play(1)
sleep(2)

while True:
    if busypin.value() == 1:
        music.play('next')
        sleep(.2)
    if (butnext.value()==0):
        music.stop()
        sleep(.2)
        print ("next number")
        music.play('next')
        sleep(.2)
    if (butprev.value()==0):
        music.stop()
        sleep(.2)
        print ("previous number")
        music.play('prev')
        sleep(.2)
    if (butvolup.value()==0):
        vol = vol + 1
        print ("Volume : ",vol)
        music.volume(vol)
        sleep(.2)
    if (butvoldwn.value()==0):
        vol = vol - 1
        print ("Volume : ",vol)
        music.volume(vol)
        sleep(.2)

After all the explanation above I do not think this program needs any more explanation.

Not all commands are available. You can add buttons and alter the program to your whishes with the commands described above.

Just one thing:
At the beginning of the program the volume is set to 20. This is a moderate setting. It is set at such a volume that you will not damage your ears when using earphones or a headphone. You can always adjust the volume later with the volume buttons.

Till next time
Have fun

Luc Volders

Automatically mount USB sticks and drives on Raspberry Pi

For an index to all my stories click this text.

I am building several systems for self hosting all kinds of services. That is because I am fed up with a lot of cloud services that just suddenly stop or move away from being a free service and start charging fees. Read my rant about this here : https://lucstechblog.blogspot.com/2026/04/my-rant-against-some-cloud-services.html

The solution is to self-host services. And I am using multiple Raspberry Pi's for that.
And I must say that that feels really satisfying.

USB devices

I use usb memory sticks for storage of some of the files. There is a reason for that: It is easy and quick to remove the usb drive for updating the files on a different machine.

Now if you are running your Pi's with a Desktop mounting USB sticks and drives is painless. 
I am running these Raspberry Pi's headless. Mounting and unmounting USB sticks or drives is a tedious task and I forget it sometimes. When that happens my server obviously doesn't work.

So I was looking for an easy way to mount and unmount USB sticks/drives. And of course there is a great solution available.

pi-usb-automount

pi-usb-automount is simple to use.
Just plug the USB stick or drive in the USB port of your computer and it is automatically mounted as USB0. Add another stick or drive and that will automatically become USB1 etc. The maximum amount of usb devices you can use is 8 (USB0 - USB7).

Installing pi-usb-automount

Before using it we have to install it.

pi-usb-automount is hosted on Github and can be found (inclusive the documentation) here:
https://github.com/fasteddy516/pi-usb-automount

We can download the repositry when GIT is installed on the Raspberry PI. And that is unfortunately standard not the case. So we have to install that first:

sudo apt install git

It does not take long and takes only about 53 MB. So that is no threat for your storage capacity.

When GIT is installed we can download the repositry.

wget https://github.com/fasteddy516/pi-usb-automount/releases/latest/download/pi-usb-automount.deb

And then we can install it with:

sudo dpkg -i pi-usb-automount.deb

That is all.

The USB drives will be mounted on /media/usb0/  /media/usb1/  etc.

Success ????

Let's see if it works.

First let's see what happens if no USB drive is plugged in.

First we point to the USB0 directory with cd /media/USB0/
And then we list the content with LS

AS you can see there is nothing there.

Now plug in a USB stick or drive.

And there it is !!!!!
I used an empty USB stick with just one file on it with the name testfile.txt.

Reboot

Now what happens if we leave the USB stick in the Pi and reboot the system.

And there it already is !!!

This is really the easiest way to mount USB sticks and drives.

Till next time
have fun

Luc Volders