HM-133/151 DTMF Microphone Project SW Repo Page

Updated 11/23/2019

(Back to the HM133/151 Project page...)
This page provides support information for the HM-133 DTMF Adapter Project Software Source Code

This is a small adapter that allows the HM-133 (or HM-151) to act as a general purpose, DTMF microphone.

A small microcontroller is used to capture digital information from the HM-133 and convert the keypresses into DTMF tones. In addition, function buttons are implemented to allow accessory buttons on some radios to be supported. A status LED (that can be located in the microphone, if desired) indicates when keypresses are detected and stays off while the mic audio is muted for tone generation or tone guard time. The brightness of the LED is adjustable using the HM-133 keypad to allow comfortable operation day or night. Lastly, a "macro mode" allows the up or down buttons to be pulsed up to 99 times to facilitate long frequency moves, or known steps through memories.

The source code repo is available at my HM133 Github location.

The openscad cover code repo is also available at my HM133 cover Github location.