Make a Bluetooth foot pedal

If you fancy having a go at making a Bluetooth foot pedal, you can do this without spending too much money. It's also a relatively straightforward project if you know how to use a soldering iron!

My footpedal and contributions from others are shown below. Unfortunately the Bluetooth board I used is not currently available, but thanks to our amazing community, Leo has kindly come up with an alternative and a quick guide of how to do this yourself!

If you want to modify an old footswitch, this is free, otherwise you can purchase a blank Hammond project enclosure box and separate SPST switches. Thin metal enclosures are fine, but they can interfere with Bluetooth range.

Equipment you will need:

  • ESP32 WiFi/Bluetooth development board (approx £6/€8)

  • DC Power Jack fitting your power supply (German shop MusikDing or UK alternative from CPC (approx £0.80 or €0.55). Alternatively you can use a battery or USB input on the ESP32 board for power.

  • Female-Female Dupont Wires / Jumper Wires from CPC (approx £1.80 / €2.00)

  • LED & resistor & mount from CPC in UK: LED, resistor, and mount or German LED, resistor, mount (about £1/€1) total . Use this website to help you calculate the best resistor size to use depending on your input voltage and led voltage, however, most LEDs will cope with a resistor between 200 Ohms and 1k Ohms.

  • Computer with USB to program the ESP32 board running the free Arduino IDE software.

  • Heat shrink tube or electrical tape, solder iron + solder

The ESP32 is programmed with the Arduino IDE using two special libraries - the keypad library and the bluetooth keyboard library.

Useful links:

Arduino IDE: https://www.arduino.cc/en/Main/Software

Installing the ESP32 in Arduino: https://randomnerdtutorials.com/installing-the-esp32-board-in-arduino-ide-windows-instructions/

Keypad Library: https://playground.arduino.cc/Code/Keypad/

Bluetooth Keyboard library: https://github.com/T-vK/ESP32-BLE-Keyboard/releases


Leo's downloadable code is available here:

A simple circuit diagram is shown below.

If you can't afford to buy a Bluetooth foot pedal to use with OpenSongApp, here's another option - make your own! I did this by modifying a foot pedal I rarely used for my Behringer Bass V-Amp effect pedal.

My old pedal
My old pedal rear

The good thing about this pedal was that it was virtually empty inside (two small micro switches and a cable). The downside, was that it was made from a really tough metal (either hardened steel or a strong alloy) making drilling and cutting a very laborious task! If I made another pedal, I would buy a Hammond enclosure and two foot switches. This would cost about £15 if you shop around (about £10 for the enclosure and about £5 for 2x SPST momentary foot switches). Whatever route you choose - modify existing pedal or build from scratch, the process is pretty much the same.

enclosure
Switch

Tools you will need -

  • Solder iron (preferably with a small, fine tip), solder, crocodile clips to hold stuff while it solders!

  • Electrical wire (usually described as equipment wire). I used single core, 0.7mm diameter.

  • Drill with metal drill bits

  • Metal file

  • Metal hacksaw

  • Glue gun (or as a second choice - duct tape) to attach the LEDs and Bluetooth circuit board to a foam pad and the foot pedal case.

Stuff you will need to make or convert your pedal (I assume you have a two button pedal like mine or have an enclosure with two switches as above).

  • Adafruit's Bluefruit EZ-Key Controller (http://www.adafruit.com/products/1535) - costs about £20 including delivery

  • Extra mono jack sockets if you want to add extra pedal inputs to your pedal (you can have up to 12 buttons). I added two extra, although I've never used them, These cost about £2 for two, but completely optional

  • Stereo jack socket if you are replacing a wired pedal like mine to allow you to plug a cable back in if you want to still use it for its original purpose. These cost about £2 for two, but completely optional.

  • Small push to make momentary button switch to allow for pairing to new devices. Costs around £1

  • LEDs x2 and 1kOhm resistors x2. These are to show the status of the pairing and button presses. These are optional, but only cost about £1 total. They also make it look cool!

  • Battery compartment (9V tray type). You could just put the battery inside the enclosure/pedal, but this method saves you having to open up the pedal to replace the battery. Costs around £2

  • On/off power toggle switch to save your battery. Costs around £0.50

  • Scrap bit of foam (I cut a bit off a car sponge) to attach the Bluetooth controller to before glueing it to the metal case - this is to avoid electrical shorting. Should be free if you know someone with a car!

Total cost of modifying a pedal with minimum options = £21.50

Total cost of full bells and whistles pedal modification (what I've done below) = £28.50

Total cost of building a basic pedal with minimum options from scratch = £36.50

Total cost of building a full bells and whistles pedal from scratch = £43.50

You can also buy commercial options from PageFlip or AirTurn, but I found these difficult to source in the UK.

Here's how my pedal looks now (you can see the cool blue LED light indicating pairing status!)......

adafruits
Pedal inside
pedal on
Pedal rear

The round button on the top underneath the LEDs is the pair button that allows me to pair new devices with the pedal.

The jack on the back allows me to use a TRS/stereo jack cable to reattach my pedal to my Behringer Bass V-Amp again should I need to. It is also hard-wired across the Previous and Next jacks.

The jacks on the left side are to allow optional scroll up/scroll down pedals, but I don't think I'll ever use them!

I used the following tutorial from the Adafruit website as a basis for my pedal, but I wanted something more robust and completely enclosed.

https://learn.adafruit.com/bluefruit-bluetooth-wireless-foot-pedal-switch

Below is a schematic circuit diagram for my pedal - it really isn't that difficult if you're happy with basic High School electrical circuits and simple DIY. For interest I wired the 'Previous/Down' pedal to the left arrow key and the 'Next/Up' pedal to the right arrow key. This also makes the pedal compatible with most eReader apps. Make sure your enclosure is big enough to hold everything and make sure you avoid short circuits!

Circuit diagram

Check out this awesome Instructable.

http://www.instructables.com/id/Bluetooth-page-turner-pedal-for-sheet-music-apps

Some user submitted pedals.........

Another, slightly cheaper option is to hack a mini Bluetooth keyboard (available on eBay for about £10). You can solder across the keyboard contacts to give a huge number of potential key presses. Either hard wire the cable into a pedal, or add a jack that connects to an existing pedal.

Keyboard

Here is another 'from scratch' pedal created by Alistair. A very nice looking pedal it is too!

Alistair has included a spreadsheet with the component list, links and prices. Make sure you secure the Adafruit board avoiding shorting and secure the battery. This can be found at the bottom of the page.

Together
components
Alistairs pedal