Matrix Frequencies | Microcontroller › AVR › Matrix Frequencies This topic has 0 replies, 1 voice, and was last updated 11 years, 7 months ago by Mridul Agarwal. Viewing 1 post (of 1 total) Author Posts April 27, 2013 at 4:41 am #4815 Mridul AgarwalParticipant I have got a 4*4 matrix keypad and I have a confusion that it will produce DTMF frequencies or not. Can someone help me out in telling that will it produce DTMF frequencies or not? For convenience I have attached my keypad’s photo:- Front View Back View Side View Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In