I was thinking to build a very small USB Audio Streaming device with aux output for an amp (I know they already exist, but I like the self invention). So I bought an Arduino Nano and a USB Bluetooth device with was originally for a computer. But I thought I might use it on the Arduino. After I removed the housing and soldered four wires onto the USB plug:


I needed to know how to wire them:


So I connected:

  • "1" to 5V+ on arduino
  • "2" and "3" need to be connected to txd and rxd on the arduino (but I don't know whitch way around)... I read that I need to have 3.3v on "3" or the "+" wire but I have 5V Output on the digital Pins on the arduino (so I need some resistors, but I'm not familiar with calculating them).
  • "4" to gnd

Can someone confirm and / or provide some information for me to get this thing running (Bluetooth device enabled and functioning)?

Further steps would be:

  • coding the arduino to Use the Bluetooth module for audio streaming - preferrably three Channel.
  • configure the arduino to give the stream to an amp.

I know my knowledge of electronics is not very good and I need some education. If you can provide some good learning websites - feel free to suggest.

  • Do note that USB (universal serial bus) is not the same As the other serial bus. USB is by itself -I dont think is hard-but it does, Truly use a lot of layers In the protocol you need to get correct to get. I give a link be low. to a USB host implemented in software for ATMEGA32 I see the source code is there-which you may try and modify for your uses, Read the USB software is implemented in using the tx and rx type pins of ATMEGA 32 -(the pairs of pins corresponding to D+,D-)- as they write on the page there its easy to write a keyboard driver (though not done). Commented Nov 6, 2016 at 21:50
  • Only a few componenets are used in the solution there. courses.cit.cornell.edu/ee476/FinalProjects/s2007/… Commented Nov 6, 2016 at 21:51
  • This is a suggestionfor a starting point-note that its low speed USB so maybe its not fast enough for your device-but maybe you can find a workaround for this Commented Nov 7, 2016 at 15:17

1 Answer 1


Interfacing an Arduino with USB is already VERY hard. USB does not use the same Serial as protocol so don't connect it to Tx and Rx. The only way to interface an Arduino and an USB device is trough a USB shield, which is quite complex already.

Just for you information. USB uses 5V so no voltage divider is needed to reduce it to 3.3V. A voltage divider is pretty much 2 resistors in series where the original voltage goes in one end, the output voltages is between the 2 resistors and the other end is connected to ground. Read more about them here.

Now, communicating with Bluetooth is also complicated, but mix USB + Bluetooth and you get something ALMOST impossible (I hope the ALMOST is clear enough for any hatters). It is possible, but seeing you level of knowlage, simply don't risk having a severe depression trying to fingure it out!

In the end of the day, your plan of using that Bluetooth USB module is just going to be crazy complicated and big.

A more effective solution would be to use a module such as the HC-05 Bluetooth module. It is quite cheap if you get it from sites such as Amazon. Link here for this product on Amazon.com. It is designed with the Arduino in mind thus making programming easier. You project could also be a little smaller, because this module pretty much has the size of your Arduino Nano.

Hope it was helpful!

  • A lot you have said here is right, but there's a glaring error. While USB uses 5v power the signalling is not 5v. When a low-speed USB connection is crudely implemented in software using GPIO pins of a 5v MCU, voltage translation is required. Of course it's not going to work for the purposes of the question anyway, but the data lines are not rated for 5v. Commented Nov 7, 2016 at 6:42

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