[arm-allstar] DTMF tones not decoded properly

Don Backstrom - AA7AU z-armallstar at deliberate.net
Fri Mar 29 13:29:58 EDT 2019

On Fri 29-Mar-19 09:19, "B Harvey via ARM-allstar" wrote:
> I don't remember if I confirmed wideband operation.

	Best double-check that. Narrowband can give you real hard-to-diagnose 
DTMF issues. We've had DTMF problems with our "Chili" units based on the 
SA818 chips:

	"One other serious issue we discovered during our design and testing 
was that all of the SA-818/DR-818 Modules we tested have their 
Wide/Narrow Band command locked in the Narrow Band mode from the factory 
and will not actually program to wideband. No error is returned when 
programming, the module just stays in narrow-band! So after literally 
months of discussion with the manufacturer, we finally were able to 
acquire a programmer and the appropriate firmware for the modules to 
make them perform as expected."

	Apparently no one else had reported this difficult-to-discover issue to 
the manufacturer. We definitely spent some time chasing our tails on 
this one. Bottom line: never assume! As a great man once said: Trust, 
but verify.


	- Don - AA7AU

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