PiFmRds on Raspberry Pi 4

[Salisito]

Hi
I've buyed a Raspberry Pi 4, 2gb RAM. Before I've had the Raspberry Pi 3 with PiFmRds working. Now I've installed PiFmRds on the raspi 4 and when I run the command, the console says me that it's working in X frequency but in really not, when I tune the frequency that I've set, there's white noise.
Has the new raspberry the gpio4 FM disabled or something like this?

Thanks

[ChristopheJacquet]

Did you use the latest version of the code? Support for the Raspberry Pi 4 was contributed by @markondej a few days ago. I personally don't have a RPi 4 to test.

[Salisito]

I've installed PiFmRds just yesterday using git clone https://github.com/ChristopheJacquet/PiFmRds.git

[markondej]

I've just double checked it on RPi4 2GB and on July's Raspbian lite distro it works like a charm (I do always use lite distros). Maybe there's a problem with used DMA channel, try changing definition of DMA_BASE_OFFSET from 0x00007000 to 0x00007500, 0x00007900 etc. (there are 15 DMA channels available).
https://github.com/ChristopheJacquet/PiFmRds/blob/master/src/pi_fm_rds.c#L151
I'll try to test it on newest Raspbian (released week ago) and will let you know if any issues occur.

[Salisito]

I'm going to install lite distro and I'll try again. At the moment I've changed DMA channels and it stills not work.

[Salisito]

I've installed Raspi Lite and PiFmRds and still don't work. When I play something, there are like some interferences. I've also triied in other frequencies. I attach video.

https://drive.google.com/open?id=1CMSGVK1XaeZNwmoAK21N4mxBpRP288cy

Also, when I've wrote "make clean" I've got this:

pi@raspberrypi:~ /PiFmRds/src $ make clean
rm -f *.o
pi@raspberrypi:~ /PiFmRds/src $ make
gcc -Wall -std=gnu99 -c -g -march=armv7-a -O3 -mtune=arm1176jzf-s -mfloat-abi=ha rd -mfpu=vfp -ffast-math -DRASPI=4 rds.c
rds.c: In function ‘set_rds_rt’:
rds.c:240:5: warning: ‘strncpy’ specified bound 64 equals destination size [-Wst ringop-truncation]
strncpy(rds_params.rt, rt, 64);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rds.c: In function ‘set_rds_ps’:
rds.c:247:5: warning: ‘strncpy’ specified bound 8 equals destination size [-Wstr ingop-truncation]
strncpy(rds_params.ps, ps, 8);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
gcc -Wall -std=gnu99 -c -g -march=armv7-a -O3 -mtune=arm1176jzf-s -mfloat-abi=ha rd -mfpu=vfp -ffast-math -DRASPI=4 waveforms.c
gcc -Wall -std=gnu99 -c -g -march=armv7-a -O3 -mtune=arm1176jzf-s -mfloat-abi=ha rd -mfpu=vfp -ffast-math -DRASPI=4 pi_fm_rds.c
gcc -Wall -std=gnu99 -c -g -march=armv7-a -O3 -mtune=arm1176jzf-s -mfloat-abi=ha rd -mfpu=vfp -ffast-math -DRASPI=4 fm_mpx.c
gcc -Wall -std=gnu99 -c -g -march=armv7-a -O3 -mtune=arm1176jzf-s -mfloat-abi=ha rd -mfpu=vfp -ffast-math -DRASPI=4 control_pipe.c
gcc -Wall -std=gnu99 -c -g -march=armv7-a -O3 -mtune=arm1176jzf-s -mfloat-abi=ha rd -mfpu=vfp -ffast-math -DRASPI=4 mailbox.c
gcc -o pi_fm_rds rds.o waveforms.o mailbox.o pi_fm_rds.o fm_mpx.o control_pipe.o -lm -lsndfile

[Salisito]

@markondej I've also tryied to install your repository and it doesn't work (https://github.com/markondej/fm_transmitter)

[markondej]

Checked newest Raspbian release and yes, it doesn't work (26 sep 2019). When simply simulating carrier via clock output (on GPIO4) the generated signal is noisy. I have no idea if this is problem with output itself or with clock source (PLLD). Like I wrote earlier everything seemed to work on July's release. I guess they messed something up with firmware (were there any GPU performance releated changes etc?). I will try to change clock source to any other and find out if this would work.

[Salisito]

Okey, I hope you can fix it!!

Thaanks

[Salisito]

@markondej have you been able to solve the problem?

[markondej]

Nope, but I've managed to bypass it a little bit. You can switch to GPIO21 instead of GPIO4. I made branch with this "feature".

https://github.com/markondej/PiFmRds

It seemed to work, but there is still a lot of noise...

[Salisito]

It doesn't work for me...

[captroy]

I am also having an issue transmitting with the PI 4. I pulled the branch using GPIO21, and also had could not get this working properly.

I can see the change in GQRX when I start he fm_rds command, but, nothing is distinguishable.

[GithubKillsMyOpsec]

I seem to be having the same issue =/

[waterwin]

Maybe this is a pointer to the right solution

Richard G Hirst added RPi4B support to his ServoBlaster and comments on DMA as follows:

The DMA channel used depends on the SOC type. If the Pi has a BCM2711
(Pi4B only, at present) then it uses channel 7; otherwise it uses channel 14.

Source = https://github.com/richardghirst/PiBits/tree/master/ServoBlaster

[henry-shadowjet]

Hi all,
Thanks for the very useful and neat program.

I have the Raspberry Pi4 with 4GB RAM, running the latest Raspbian Buster distro. Downloaded and compiled the source with no issues (thank you!).

However the problem is I can't seem to get the signal to output an audible signal. The progeam does not generate any error, but when I tune my car radio to the signal it's supposedly outputting signal to, the only thing I can hear is pulses. Something is there though because it is clearly different when the program is running vs not running. But yeah, all I can hear is small pulses, no matter which .wav I used on the -audio tag (I tried all the different supplied samples).

Any pointer in the right direction would be much appreciated! I know a problem is already recognised in the above convo, just in case this is a bit different.

Thanks in advance, and keep up the great work!

[JokrCode]

Hi all,
Thanks for the very useful and neat program.

I have the Raspberry Pi4 with 4GB RAM, running the latest Raspbian Buster distro. Downloaded and compiled the source with no issues (thank you!).

However the problem is I can't seem to get the signal to output an audible signal. The progeam does not generate any error, but when I tune my car radio to the signal it's supposedly outputting signal to, the only thing I can hear is pulses. Something is there though because it is clearly different when the program is running vs not running. But yeah, all I can hear is small pulses, no matter which .wav I used on the -audio tag (I tried all the different supplied samples).

Any pointer in the right direction would be much appreciated! I know a problem is already recognised in the above convo, just in case this is a bit different.

Thanks in advance, and keep up the great work!

I'm in the same boat. I have rasberry pi 4 2gigs. I'm running kali and ssh into it I feel like everything's install commands run but nothing happens. Just s tiny bit of static? I'm not sure if it's running properly. Maybe my signal isnt strong enough but the cord is right next to my antenna. I think this is updated to work for pi 4 but idk if the make clean and make command is working? Let me know if you get it to work.

[henry-shadowjet]

There was just a kernel update today to 4.19.97-v7l+, so I tried it again with much anticipation, but unfortunately yielded the same result. Still the same static and pulses.

I do have a short wire same as you do, but the radio antenna and the wire is pretty much touching each other so I assume that's not an issue, but thought I should mention it just in case.

Thanks everyone. Any info would be appreciated.

[JokrCode]

Same with mine I get nothing but I do see something happening but seems not strong enough to take over. Theres another kernel update recently but I haven't done either of them. Is there a way to do it on kali I just dont wanna reinstall it all again just to update the kernel

[henry-shadowjet]

Since the new kernel update, I can't even get the pulsing sound I get before. Now it's as if nothing happens when I activate the program. Go figure. Haha

[markondej]

Lately I've had some time to play with spectrum analyzer, and this is what worked for me:
First, try switching antenna to GPIO21 (last PIN on RPi4 header) using my branch ( https://github.com/markondej/PiFmRds ). Before you start transmitting switch ARM core frequency scaling governor to "performance" settings:

echo "performance"| sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

Finally use frequencies below 93.5 MHz

sudo ./pi_fm_rds -audio pulses.wav -freq 92

[Salisito]

Wow @markondej, now it works!! But the audio quality is not like before...

[Salisito]

There's like a distorsion

[goutx2]

Hello
I am trying to get transmission above 93 mhz but no chance
My question is why we cant transmite above 93 mhz
And i want tell you they published "bcm2711 arm periferals.pdf"
take a look at
https://github.com/raspberrypi/documentation/tree/master/hardware/raspberrypi/bcm2711

[Budgiebrain994]

Hi there - same deal. I'm on a Raspberry Pi 4, with 4GB of RAM. But instead, I've installed Ubuntu 64bit. I've had no luck running the application, or any available variation. It uses a different architecture (armv8a + aarch64). Given the FPU is not available on this platform, am I right in speculating we won't be having much luck for a while? I'm not good with such low-level code myself.

[makew0rld]

The Pi 4 is known to have issues, see this repo that mentions it.

[doctorsax]

Bonjour, quand je veux compilé le programme sur ma raspberry pi 4 4g en utilisant make, il me met des message d'erreur comment les résoudre ?

[ChristopheJacquet]

@doctorsax A priori le programme ne fonctionne pas, ou pas bien, sur RPi 4. Cependant la compilation devrait réussir. Vérifiez que vous avez bien toutes les dépendances listées dans le README.

[doctorsax]

@ChristopheJacquet Bonjour j'ai regarder mais toujours le même message d'erreur

[makew0rld]

@doctorsax C'est pas une erreur, mais juste un avertissement. Tu peux l'ignorer, je pense.

[doctorsax]

@makeworld-the-better-one Justement j'ai essayer mais le programme ne veut pas se lancer

[makew0rld]

Quel est le résultat quand tu exécutes ./pi_fm_rds? Je ne suis pas le developer, mais je sais que c'est cette résultat que Christophe a besoin.

[comicsansgreenki]

Weird. I'm running the compiled binary just fine on my Raspberry Pi 400.

[captroy]

Hey all, I think I have a fix for this issue. I've successfully transmitted RDS on my pi 4, and put a pull request for the code change. Fingers crossed this works for group!

I should mention, this is thanks to @1anakin20 for his fix on the pi-rc project. @ @

[comicsansgreenki]

Hey all, I think I have a fix for this issue. I've successfully transmitted RDS on my pi 4, and put a pull request for the code change. Fingers crossed this works for group!

I should mention, this is thanks to @1anakin20 for his fix on the pi-rc project. @ @

Ooooo. Can't wait to test once I get back home.

[jurosic]

still cant get this to work on my rpi4 running raspbian lite, i have an antenna and i am standing next to mi radio but only white noise, there is a difference when i start/stop the broadcast, but no actual audio plays

[StefCoders]

This worked perfectly echo "performance"| sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

[comicsansgreenki]

@StefCoders ooh nice! did this let you use a display output with the pi4 simultaneously?

[StefCoders]

Nope, headless pi and ssh..

[Salisito]

This worked perfectly echo "performance"| sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

@StefCoders what else did you do to make work PiFmRds? Which repository did you use? Thanks in advance

[StefCoders]

I just used this one. Nothing else.

[crisdash96]

this Soultion witch not working pifmrds fm transmitter

Put the cable in pin Numbers 6

[Salisito]

Hi all,
It's been a long time since this issue was reported. Has someone achieved to make work PiFmRds in a RPI4?