Close
0%
0%

Portami

Battery-powered polyphonic synth designed to be a companion to small Midi keyboards.

turiTuri
Following
Liked Like project

Just one more thing

To make the experience fit your profile, pick a username and tell us what interests you.

Pick an awesome username
hackaday.io/
Your profile's URL: hackaday.io/username. Max 25 alphanumeric characters.
Pick a few interests
Projects that share your interests
People that share your interests

We found and based on your interests.

Choose more interests.

OK, I'm done! Skip
Similar projects worth following
719 views
2 comments
2 followers
View Gallery
Portami is a portable, battery-powered polyphonic synth built around a SAMD21 microcontroller. It's designed to be a companion to small Midi keyboards.

The software is a fork of Marcel Licence's excellent code: https://github.com/marcel-licence/samd21_mini_synth

My implementation focuses on USB Midi communication (Midi-in through the onboard USB-C port) and features a push button to cycle between wave types (sine, saw, square, pulse, triangle, and noise). An RGB led inside the button changes color according to the current wave type.

Other than the onboard speaker driven by an LM386 amplifier, Portami has a 3.5" mini-jack port to plug a pair of headphones. The audio socket has a switching mechanism, disconnecting the speaker when in use.

The whole setup is powered by a 3.7V, 1100mAh li-ion battery, recharged and protected by a TP4056 USB-C charger module. A regulator boosts voltage to 5V, providing power to the Midi keyboard.

  • 1 × Seeed Studio XIAO SAMD21 (Seeeduino XIAO)
  • 1 × TP4056 battery charger module
  • 1 × 18650 or equivalent lithium battery
  • 1 × Voltage regulator (like boost converter MT3608)
  • 1 × LM386 audio power amplifier IC

View all 20 components

View project log

Enjoy this project?

Share

Discussions

velix wrote 01/04/2023 at 08:22 • point

Great Project, I like it!
Just seen, that the potentiometer can pull the output of the SAMD21 to ground, when on zero position, so it shorts the output pin. I suggest feeding the signal output to one end of the potentiometer and the other end to ground, while picking up the signal from the slider pin and feeding it to the LM386.

  Are you sure? yes | no

Turi wrote 01/04/2023 at 12:46 • point

That's a mistake in the schematic, thank you for spotting it!
I'll update it shortly.

  Are you sure? yes | no

Similar Projects

USB MIDI chord strummer kit for Teensy 3.2 (MIDI and built in audio output) or Teensy LC (MIDI only).
Project Owner Contributor

T. Chordstrum

johan-berglundJohan Berglund

The smallest USB-C LiPo charger
Project Owner Contributor

Ant USB-C LiPo Charger

beast-devicesBeast Devices

A simple setup page describing all the functions of ICStation's charger module and how to use them individually.
Project Owner Contributor

Dual USB Mobile Battery Charger Setup

electorialsElectorials

Charger system for Li batteries with fuel gauge. Works with Qi wireless or USB power source. For sale on Tindie.
Project Owner Contributor

Qi and USB Li Charger Flex Module

chris-hamiltonChris Hamilton

Does this project spark your interest?

Become a member to follow this project and never miss any updates

Going up?

About Us Contact Hackaday.io Give Feedback Terms of Use Privacy Policy Hackaday API

© 2025 Hackaday

Yes, delete it Cancel

Report project as inappropriate

You are about to report the project "Portami", please tell us the reason.

Send message

Your application has been submitted.

Remove Member

Are you sure you want to remove yourself as a member for this project?

Project owner will be notified upon removal.