CTR2-MIDI is a USB and Bluetooth-LE MIDI controller that can be used with Apple iOS and Mac devices running Marcus Roskosch’s (DL8MRE) excellent SmartSDR and SDR-Control software and with Windows apps such as Thetis for the Apache Labs ANAN and Hermes-Lite 2 SDR radios. CTR2-MIDI provides a physical tuning knob, paddle/straight key/PTT switch interface, six dual-function pushbuttons, and 8 encoder controls.

CTR2-MIDI firmware runs on both CTR2-MIDI (S3 version) and CTR2-Micro hardware (C3 version). The CTR2-Micro is implementation is limited to three dual-mode pushbuttons and one status LED.

April 24, 2024: v1.01.00 – MAJOR UPDATE!

This update adds USB MIDI functionality to CTR2-MIDI. This means it is now plug and play with most computers and devices that support USB MIDI. This update also adds additional MIDI control types. Select from MIDI Button, SliderA, SliderB, WheelA, and WheelB.

  • SliderB adds audible detents to the slider control. This is handy when controlling RIT or XIT. CTR2-MIDI will beep when the control is centered or hits an upper or lower limit.
  • WheelA adds proportional tuning to SmartSDR and SDR-Control.

Instructions for flashing firmware to CTR2-MIDI and CTR2-Micro can be found in the CTR2-MIDI Operation Manual under Appendix B.

Download the latest CTR2-MIDI firmware here. Older versions can be found below in the Revisions section.

S3 Version for CTR2-MIDI Hardware

The S3 version is for the new CTR2-MIDI controller

C3 Version for CTR2-Micro Hardware

The C3 version runs on the CTR2-Micro. If you own a CTR2-Micro you can download this version and use your CTR2-Micro as a Bluetooth-LE MIDI controller in SmartSDR or SDR-Control for iOS. The only difference is that the Micro only supports three dual-mode pushbuttons, only has one status LED, and doesn’t support USB MIDI.

NOTE: If the Download button doesn’t appear, click the hyperlinked file name to download the zip file.

If you’re a Windows user you can download the Flash Downloader program referenced in the Updating Firmware section of the CTR2-Micro Operation Manual for Windows users to update your Micro’s firmware.

If you’re a Linux or Mac user, download the following script and follow the instructions in the Updating Firmware section for Linux and Mac users. I’d like to thank Lou, KI5FTY, for creating this script.

The zip file includes a copy of the CTR2-MIDI Operation Manual and a copy of the MIDI mapping I use on my devices. You can import the CTR2-MIDI.map file into your app by using the Import Map feature in the app’s Import Mapping from iCloud Drive option in the Edit MIDI Controller Map panel. Copy the .map file to the SmartSDR folder on your device.

Change Log

March 26, 2024: v1.00.05 – Recommended update

  • Revised ADC read code to minimize false triggers when pressing multi-function buttons (MFBs)
  • Added Show/Hide MFB Counts to terminal interface to aid in troubleshooting MFB problems
  • Updated Troubleshooting section in the Operation Manual to include the No Sidetone solution

March 23, 2024: v1.00.04

  • Flash green LED on S3 firmware when unit is powered up. There is no need to update the firmware if you’re running v1.00.03 “C3” on a CTR2-Micro

March 10, 2024: v1.00.03

  • Initial release of CTR2-MIDI firmware for both ESP32-C3 (for CTR2-Micro) and ESP32-S3 (for CTR2-MIDI) processors.