2021-02-23

Buyer beware! TEA5767 Modules Good Vs. Bad

There are two distinct versions of the TEA5767 FM Radio modules being sold by various internet vendors. One good and one bad. The good version works quite well and the bad version exhibits behaviour that renders it nearly useless.

What does the bad version do? Well, Comvette polls the TEA5767 module periodically (every 5 seconds) to retrieve the Stereo Indicator and Signal Strength data. When this polling occurs, the audio output from the module is replaced with white noise for the duration of the polling.

The video below demonstrates the white noise problem when polling a "bad" TEA5767 module.

Characteristics of a good module:

The TEA5767 module that works well is shown to the right.

It has:

• Squared PCB corners
• Larger mounting holes
• Daughter-board solder-pads that run west to east
• A crystal that is mounted in a north to south orientation
• A slightly larger PCB

Characteristics of a bad module:

The TEA5767 module that works badly is shown to the right.

It has:

• Rounded PCB corners
• Smaller mounting holes
• Daughter-board solder-pads that run north to south
• A crystal that is mounted in a east to west orientation
• A slightly smaller PCB

If your project does not require the ability to display the Stereo Indicator and Signal Strength then the "bad" module will perform acceptably.

But for projects like Comvette that require the ability to display the Stereo Indicator and Signal Strength the "good" module is your only option. You should ask your vendor to verify which TEA5767 module they are providing. It may be helpful to them with a link to this page to help them identify which module they are selling.

NOTE: Because of the uncertainty of receiving a "good" TEA5767 module when purchasing from an internet vendor and because the TEA5767 module does not support the Radio Data System (RDS) protocol employed by most modern FM radios, I am considering alternative FM radio modules to use with Comvette. I will post blog and code updates if I switch to an alternate FM module.