This app was mentioned in 4 comments, with an average of 1.00 upvote
So far the best solution I've been able to come up with is using this app to listen for the dtmf tones and have auto input scrape the info and parse it into a trigger.
My current concern is achieving this while the screen is off. (I have root which should help) but I dont know if i can scrape text while the display is off.
Anyone have any suggestions?
There's nothing wrong with the '"Old School" DTMF method' (As you called it) - No need for anyone to reinvent that wheel. There are Android DTMF tone generators that store macros - One example being https://play.google.com/store/apps/details?id=com.wolphi.dtmf That one even advertises to amateur radio operators in it's description ;)
Nice!!
I simply use this listening on an SDR (sperate audio feed into phone)
https://play.google.com/store/apps/details?id=com.wolphi.dtmf
they make tone boards for most old radios, there is a andriod app in the store that can do DTMF - HERES ONE https://play.google.com/store/apps/details?id=com.wolphi.dtmf