Continue to Site

Welcome to

Welcome to our site! is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

MIDI Note Trigger Circuit - Help

Not open for further replies.


Newbie level 5
Sep 8, 2004
Reaction score
Trophy points
Houston, TX, USA
Activity points
midi to trigger

A while back, using some schematics and info I found on the net, I was able to make me a MIDI controlled switch. When it received a certain midi signal it activated a relay to close a connection on a 1/4" input, thus controlling a remote pedal for my guitar.

Now, I have advance my setup a bit and am faced with a new challenge. I want to make a pedal that sends a MIDI note. I envision the pedal having 4 buttons (UP, PLAY, STOP, DOWN) and a 3 digit LED display to display what note number is currently being sent. I am going to use this to trigger some sound effects on a computer based sampler.

I have come up with a quick schematic (no it isn't 100% correct nor complete), but not 100% knowing what I am doing, I need some guidance on corrections or ways to make this do what I want, but simpler.

**broken link removed**

I will write a C program for the 16F628 to increment/decrement the current MIDI note number, send the current note number out via the MIDI port when PLAY is pressed, and send a stop note when STOP is pressed, and send the current MIDI note number to the display set (IC1). IC1 will be programmed to display the current note number on the LED Display (1-128).

So, can someone give me some assistance and see what my schematic needs in way of correction to make this work?


midi trigger

OK, I did a bit more research on the internet. I think I am going to go with a PIC Basic program for the 16F628 to control the operation and MIDI Data that is sent.

For the display, I came across a chip to use, which is the MAX7219 tp contorl the 3 digit LED Display.

I have attached my sketch of a circuit using this setup. If you could be so kind to glance over it and see if you see any glaring mistakes or think there is any reason this won't work. I'd appreciate it! :D

midi trigger circuit

is this working ...

Not open for further replies.

Part and Inventory Search

Welcome to