FM Transmitter Mod

Will do. Thanks for your help. I'll post updates on this thread.

Would another possibility be, building a GPIO board that would connect to the mod, and send out audio, the same way I did on the raspberry pi?

I'm more specifically referring to the PiFM Project on the raspberry pi.

David

Raspberry Pi Radio Transmitter: 4 Steps

The MDK does generate clock and PWM outputs, so it appears it would be feasible to use the MuC in the same manner that they used the Pi.  In this case the audio would be an analog signal out of the TFA still, correct?  You would probably need to flywire a new circuit on the Perforated board, since the Audio card doesn't provide easy access to extra GPIO.

If you run into issue configuring any MuC outputs, we're here to help.  As for how the user tunes the transmitter, than can be easily done with an Android app and pass the information to your Moto Mod using the Raw protocol.

There's an interesting comment that this isn't really a good way to do FM since you "splash" out over other channels.  I thought your FM transmitter was a separate chip, controlled by i2c like the TFA is.  Pretty interesting just modulating a GPIO signal; not sure if that is easier or harder than a transmitter IC.

Great documentation so far, really interesting to see this evolving!  But you confused me when you mentioned 2 knobs next to the speaker.

So, from my understanding, the whole purpose of the stereo decoder is to receive I2S signals from the MuC. Not the other way around. For that reason, I thought those were the pins that allowed for Word Select, and the Back Clock, and The SDO to get the audio from the phone. Is it true that these pins are outputting this information for the process of decoding it into Left out and Right out for the FM Transmitter?

My goal is to take I2S to the Stereo Decoder.

This seems like the most complicated way ever to get FM transmission. You could just take an analog audio output (headphone jack?) and send it to an FM transmitter circuit. I2S may offer higher quality for a small portion of the system, but by the time it has been transmitted and received, and bear in mind most modern FM receivers are awful, the sound quality will be pretty average anyway. Analog input FM transmitters are available all over the place, unless I'm missing something..

Yes, I understand I can do that. I just wanted to build something that would work as a mod. This is just a project to get to know everything a little better.

You're very right. Just plugging into, or Bluetooth to an FM transmitter would be a lot easier. I am purposefully trying to do something more challenging.

I've decided to switch to using PC0 and PC1 for SDA and SCL. This corresponds more with the Audio Mod

This is the Audio Amplifier for the Moto Mod personality card for the audio speaker mod. I'm trying to find patterns between the inputs that are shown between the two modules.

So instead of PD7 for Data In, I will actually use the SDI pin. (PE7)

So! For the next step. I had to take a break because of courses at school. I am going to configure the board tonight. What is the best way to get the ADAfruit stuff integrated with the board. Are there makefiles that I have to edit in the nuttx stuff. How can I get this to work with the Java portion of the Android application as well? I think I might need to study it a little more. I can't wait to see the final product.

David

Major update to the project. The board is soldered. I'm not the best at soldering, so it took me a few hours to do this.

motomodsdev - Is there any specific way that I need to import the Adafruit libraries to the board or the nuttx stuff? What make files should I edit and how etc...

motomodsdev - Is there any specific way that I need to import the Adafruit libraries to the board or the nuttx stuff? What make files should I edit and how etc...

I've continued the NuttX portion in another thread. This one seems to be good.