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-   -   [WIP] FM Receiver/Transmitter TOH (https://talk.maemo.org/showthread.php?t=93583)

kimmoli 2014-08-15 18:30

[WIP] FM Receiver/Transmitter TOH
 
This is thread for FM Receiver/Transmitter TOH (about 87.5 .. 108 MHz)

FAQ:
Q: Are you going to make this TOH for sale also or just to make a tutorial?
A: No decision made yet.

kimmoli 2014-08-15 18:31

Re: [WIP] FM Receiver/Transmitter TOH
 
Those who follow me on twitter may have seen this short video;

https://www.youtube.com/watch?v=xTO2Q3jX8Z8

It is simply RRD-102 V2.0 board attached to MyHalf breakout board. The board contains RDA5807M chip and 32.768kHz crystal and passives for bypass and antenna.

https://lh6.googleusercontent.com/-J...dio-module.jpghttps://lh5.googleusercontent.com/-a...Xq6xXFXXXG.jpghttps://lh4.googleusercontent.com/-p...fmtunerpcb.jpg

MyHalf bare PCB's available through OSHPark https://oshpark.com/shared_projects/6TWMNB35

RRD-102 Boards are available from ebay, aliexpress e.g.
http://www.aliexpress.com/item/Free-...988842002.html

Datasheet can be found here http://www.seeedstudio.com/wiki/imag...sheet_v1.1.pdf

Topview of breakout board
https://lh3.googleusercontent.com/-t...n_RDA5807M.jpg

Simply connect the SDA(=DATA) and SCL(=CLOCK) to I2C bus which is converted to 3.3V levels.
3.5mm audiojack to L/R out and GND
3.3V from phone to VDD
Antenna (piece of wire) goes to FM pin
Leave N.C. and RCK pins not connected.

For reference 3.5mm plug contacts:
https://lh3.googleusercontent.com/-2...out-audio1.png

Sourcecode in my github https://github.com/kimmoli/fmreceiver

This contains minimalist UI with tuning and RDS station name and radio-text display:
https://lh6.googleusercontent.com/-I...0815214355.jpg

For the transmitter side, i did order some KT0803L chips - currently waiting them to arrive:
https://lh3.googleusercontent.com/QY...=w1035-h827-no

datasheet http://radio-z.ucoz.lv/kt_0803/KT0803L_V1.3.pdf

To get the audio from FM receiver (and to FM transmitter) to jolla audio-system is under planning. More about that when it is time for that.

meemorph 2014-08-15 18:42

Subscribed to this thread. Nice idea, be successful. ;-)

243kof 2014-08-15 19:03

Re: [WIP] FM Receiver/Transmitter TOH
 
I'm interested too! Thank you for your effort :cool:

Brudhu 2014-08-15 20:24

Re: [WIP] FM Receiver/Transmitter TOH
 
Nice, Kimmoli!

Estel 2014-08-15 20:28

Re: [WIP] FM Receiver/Transmitter TOH
 
It's a pity that you don't do things for (far superior) N900. You got clever ideas :)

carmenluci 2014-08-15 21:19

Re: [WIP] FM Receiver/Transmitter TOH
 
Great!! Good work!! I'm very interesting on this TOH.

Kabouik 2014-08-16 03:06

Re: [WIP] FM Receiver/Transmitter TOH
 
I'm in.

(And about what Estel said, I do hope you'll do things for the Neo900! N900 is indeed the King, but it's becoming a bit slowish for nowaday's standards. :()

jalyst 2014-08-16 08:01

Re: [WIP] FM Receiver/Transmitter TOH
 
I'd like to see a bunch of these TOH's merged into one uber "kitchen-sink/swiss-army-knife" TOH ;-P
No easy task; I imagine it'd take many iterations of miniaturisation, plus the I2C BUS may start to get saturated.

kimmoli 2014-08-16 16:37

Re: [WIP] FM Receiver/Transmitter TOH
 
Quote:

Originally Posted by Estel (Post 1435947)
It's a pity that you don't do things for (far superior) N900. You got clever ideas :)

It might be due that fact i have had no pleasure to own a N900.

Quote:

Originally Posted by jalyst (Post 1435973)
... "kitchen-sink/swiss-army-knife" TOH ...

Yep. Getting started with one feature/TOH, maybe next will already combine few things.


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