FMBerry

What is this?

FMBerry is a piece of software that allows you to transmit FM radio with your Raspberry Pi.

YouTube-Video

How does it work?

It uses the Sony-Ericsson MMR-70 transmitter, which was originally intended for use with Sonys Walkman cellphones from early 2000s.

What do I need to build this?

• MMR-70 transmitter
• Raspberry Pi (compatible & tested with every Pi, Model Beta, A, B, B+, 2, Zero, 3)
• Soldering equipment (soldering iron and some solder)
• Cable for connecting to your Raspberry Pis GPIO port (old IDE cable does work fine!)

The hardware is explained here: HARDWARE.md

Installation

This software was developed under Raspbian Wheezy 2013-02-09.

Arch Linux users: AUR - fmberry-rpi-git

Step 1: Enabling I²C

Open raspi-blacklist.conf:

sudo nano /etc/modprobe.d/raspi-blacklist.conf

Comment out the Line "blacklist i2c-bcm2708" with a #. Save with Ctrl+O and close nano with Ctrl+X

To make sure I²C Support is loaded at boottime open /etc/modules.

sudo nano /etc/modules

Add the following lines:

i2c-dev

Then again, Save with Ctrl+O and then close nano with Ctrl+X.

Please reboot your Raspberry after this step.

Step 2: Installing I²C tools and dependencies for the build

First update your local package repository with sudo apt-get update

then install all needed software with the following command: sudo apt-get install i2c-tools build-essential git libconfuse-dev

Step 3: Finding out your hardware revision

Run cat /proc/cpuinfo | grep "CPU revision" in your terminal.

All Raspberry Pi's with a revision newer than rev. 2 have their i2c port connected up to /dev/i2c-1.

Older devices (beta, alpha, early 256MB Model B's) have it connected up to /dev/i2c-0.

Step 4: Checking the hardware

You can check your wiring with the following command:

i2cdetect -y 1

Please remember that you need to run the command on another port on older revisions!

i2cdetect -y 0

You should then see your transmitter at 0x66.

If you are not able to see your transmitter please double check your wiring!

If you connect you MMR-70 to I²C bus 0 on Raspberry Pi rev2 make sure that header P5 pins are configured as I²C pins!

Step 5: Building the software

To build the software execute the following commands (in your homefolder):

git clone https://github.com/Manawyrm/FMBerry/
cd FMBerry

If you have got an old revision board, please open fmberryd.c and change the RPI_REVISION definition to RPI_REV1!

make

Compiling the software will take a couple of seconds.

Step 6: Installing the software

FMBerry is essentially a daemon called fmberryd. To install it into your system path type sudo make install.

You can start it by typing sudo /etc/init.d/fmberry start.

To control the daemon you have to use ctlfmberry.

It currently allows the following commands:

• ctlfmberry set freq 99000 - Frequency in kHz (76000 - 108000)
• ctlfmberry poweron
• ctlfmberry poweroff
• ctlfmberry set rdsid DEADBEEF (8 chars! Longer strings will be truncated, shorter - padded with spaces)
• ctlfmberry set rdstext Mike Oldfield - Pictures in the Dark (max. 64 chars. Longer strings will be truncated)
• ctlfmberry set txpwr 0 - 0.5 mW Outputpower
• ctlfmberry set txpwr 1 - 0.8 mW Outputpower
• ctlfmberry set txpwr 2 - 1.0 mW Outputpower
• ctlfmberry set txpwr 3 - 2.0 mW Outputpower (Default.)
• ctlfmberry stereo on - Enables stereo signal (Default)
• ctlfmberry stereo off - Disables stereo signal
• ctlfmberry muteon - Mute audio
• ctlfmberry muteoff - Unmute audio
• ctlfmberry gainlow - Audio gain -9dB
• ctlfmberry gainoff - Audio gain 0dB"
• ctlfmberry set volume 0-6 Audio volume level 0 to 6, equal -9dB to +9db, 3dB step
• ctlfmberry status - Print current status
• ctlfmberry stop - Stop FMBerry daemon

That's it! :)

Step 7: Debugging

FMBerry writes debugging output to /var/log/syslog.

You can watch the information by running ctlfmberry log. It's essentially just a cat /var/log/syslog | grep fmberryd

It will tell you what's wrong.

Updating the software

Please check for new dependencies. You can safely just run the apt-get install command again. It will only install new dependencies if necessary.

First stop the daemon by typing /etc/init.d/fmberry stop.

Then run git pull followed by a make and a sudo make install.

You can then start FMBerry again with /etc/init.d/fmberry start.

Notes

• The Daemon itself is essentially a simple TCP server. It is listening to Port 42516. (set in fmberry.conf) You can control it by sending the exact same commands you would give to ctlfmberry.
• For information on How to control the Daemon have a look into ctlfmberry. It's a simple shell script.

Projects using FMBerry

https://github.com/Manawyrm/FMBerryRDSMPD (streaming of MPD title data via RDS) https://github.com/akkinitsch/FMBerryRemote (streaming of internet radio streams, controllable via Webinterface) http://achilikin.blogspot.de/2013/06/sony-ericsson-mmr-70-transmitter-led.html (enabling the LED on the transmitter to be software controllable)

Common problems

The daemon does not show anything.

That's normal. You have to use ./ctlfmberry to control the daemon.

I can't seem to hear music.

Turn up the volume/unmute your raspi with alsamixer.

I am getting compile errors.

Did you install all dependencies? (All lines with apt-get)

The transmission dies after a couple of minutes.

You didn't disable the internal processor of the MMR70. Do this by connecting TP18 to GND.

The power supply of the raspberry pi shorts out/there are no lights anymore_

There is a short circuit. Probably caused by a wiring fault or by using an 80pin IDE cable for connecting the FMBerry.

Alternative linux distributions don't detect the I2C bus (ArchLinux, OpenWRT, OSMC)

Linux 3.18 introduced a new feature called Device Tree support. To get the I²C Bus working, you need to put this configuration at the end of /boot/config.txt (change the first parameter according to the RPi you have):

device_tree=bcm2708-rpi-b-plus.dtb
device_tree_param=i2c1=on
device_tree_param=spi=on

Thanks to Daniel for the solution to that problem!