mp3 player + toggle


I have a project where I need the mp3 player bit to start playing a track once power is supplied.
I have used the mp3 player bit before with a button bit. However, I need the track to play automatically without pressing a button.

Would the toggle bit in the “on” state work to accomplish this?

Thank you for any help.

Hi @FramerX. The toggle Bit is considered a latching input, because it will hold it’s state… Below is a spreadsheet that shows how the mp3 player will work in different scenarios. I am also happy to make little video demonstration. Reply here with an exact circuit + scenario, and I’ll test your ideas. :slight_smile:

Momentary vs. Latching Inputs:
Momentary inputs are quick ON or OFF signals sent into your MP3 player. A great example would be adding a button before your MP3 module. If you briefly press the button, a quick 5 volt signal goes to the MP3 module triggering it to start or stop (depending on the mode you are in). Latching inputs stay ON or OFF for a longer period of time. For example, a toggle switch sends out a 5 volt signal for as long as it is in the ON position. For the MP3 module, any incoming signal that is longer than 3 seconds is considered a latched input, so pressing and holding the button for more than 3 seconds would be the same as leaving a toggle switch on for that same amount of time.

Read full article:

Hi @FramerX,

To start the MP3 player once power is supplied you will definetly need one single pulse on the SIG line.
I tried a lof of bits but there seems to be no bit doing that…
But I think the Arduino bit could be programmed to send one pulse when the power is supplied.
Let me know if this is the way you want to go, I could test it for you if you want… :slight_smile:

Thanks for your help

1 Like

The link to the full article doesn’t work, do you know where I could read it?

Hi @thisjustin,
Littlebits has been taken over by sphero and the exisiting data has been reorganized. Much of this is gone…
But if you search the forum using “mp3” or “mp3 player” you will find much information. In the past I have posted a lot of info about the mp3 player, you will find it…

Thanks. I know about the purchase, but was thinking that they didn’t lose all that data, but it was just under a different domain and path.

Thanks for the hint though, I’ll look. My goal is to try to figure out how to trigger the MP3 player to play specific tracks. It looks like it may be a challenge, but I think it may be possible with the Arduino, but I haven’t tried yet. I already see at least one post on the topic.

1 Like to the rescue!

Not a ton of new info there, but at least it’s not gone.

1 Like

hi @thisjustin,

I looked into this also a few years ago.
It is not possible to trigger the player to play a specific song, only by sending multiple forward or backward triggers in a row… Then you must calculate the number of triggers you need starting from where you are and take care of the trigger duration and the pause between triggers. I did not succeed to get this working…
Maybe an Arduino could do the job…

1 Like

Hi @thisjustin, I figured I could weigh in on this since I’ve previously posted a project using the Arduino to control the MP3 player, as part of a robot. You can see my complete code in this post:

The lines you are looking for invoke the variable musicPin.

With the Arduino, you can toggle the bit to play a track, and it will continue even if the toggle voltage is removed (assuming the track is long enough). However, you can only control the MP3 player’s track order through the combination of numbering the filenames and the switches on the bit. There is no way to trigger a specific track from a collection to play through either code or hardware.


Thanks to both of you. Really helpful. I’ll post what I put together if I succeed :wink:

1 Like

Hi @thisjustin. Find tips & tricks for individual Bits here:

or maybe use the way back machine. Cheers! - Jude