MK194N FM radio pretty dead

Okay, I have just assembled the FM radio board. All appears to be working except no output. Here are the symptoms: RC5 on the micro is driven low by station 1 select button. If the button is pressed quickly and then released the level on the micro pin rises to about 3.3v. If the button is held down for > 1 second and then released the level on the micro pin first rises to around two volts and the steps slowly towards 3.3v over about 5 to 10 seconds.

The rest of the button signals appear to operate as you would expect, except nothing has any affect on the radio.
There is no activity on the volume control pin, GPIO3. And the I2C bus is doing continuous reads to address 21? which appears to return a huge string of data before the request is repeated.
Is there anything else I can look at?

Looks to me like there could be something wrong with the resnet??

Well very quiet.
Des anyone have a manual or other documentation on the radio IC on the module? Think I need to start from basics.

There is some example of an arduino code on the GitHub… that contains a reference to SparkFun.
It looks like the and 11083 use the same silicon, but Welleman did their own implementation.

Too bad it does not work for some of us.


The info of the Radio IC module MM100 can be found here:

Product info WSAH194 or MK194:

FM/RDS receiver (MM100) - Whadda - Manual Platform - Category

Github code:
GitHub - Velleman/VMA11: This is a library for the Velleman VMA11 fm/rds receiver arduino shield and MM100 mini-module

If it still doesn’t work, You can also to try replace the MM100 mini module or
Bring it back to your local shop for RMA request.

Best Regards,
Velleman Technical Support

Sorry I binned the unit. No technical information available on the radio chip.
This is a real shame as it was purchased for a bright young 11 year old to find out a bit about electronics. We got a crystal set to work, built from scratch and I purchased this item for him to build next.
Real shame it was a dead duck.
Geoffrey Frost
Electronics design engineer.

So no data sheet available then. Just a few flyers.

What about digital/analog interface levels?
What about serial commands and response?

Arduino library?? Do I have to sift the code??
Very poor product and support.