I tested the AudioCapture Service. The first time I made a recording it worked fine, but the second time it failed. I found that the microphone was not released when stopping the recording, so the second attempt failed to connect to the microphone.

So I downloaded the source for MRL and found the problem in AudioCapture.java



just before the line


solves the problem :-)
Best regards




8 years 11 months ago

Hello and Welcome Mats !

What a pleasure it is to see your first post with a problem & solution in the same blog.

I've added your fix to API2 branch on github - the one we are currently working on.


We would love to hear more about you, your background and your current projects !




A few weeks ago i found the InMoov project.i just couldn't resist it. So I purchased a 3d printer, a Vertex K8400 from Velleman, and started to print. First some parts to improve the printer. Then the fingerstarter. it was really easy to get stated since i already had an Arduino Uno and several servos from a previous robot build. So that is how i found out about Myrobotlab. 

But i want my InMoov robot to be autonomous. So i want to have everything in the robot. A PC is a little to big for the body, so i use a Raspberry PI to run the MRL and to communicate with the Arduinos. Actually, I'm writing this text on the Raspberry that I also use for the MRL.

Using MRL on Raspbrerry is a bit challenging, since it doesn't have a microphone or any speakers. I will use a USB soundcard in one of the USB ports to handle that. I will also use the Raspberry camera, not a USB camera. And since i won't have a screen on InMoov, the GUI service will run on an ordinary PC and the rest on the Raspberry. So I think I have some challenges to work on. 

i'm not sure if it will work, but that really doesn't matter so much. i always learn more from faillures than from success.

Best regards











8 years 11 months ago

hi there

I try also to run my Marvin with a Raspi 2 and 2 arduino maga.

Alessandro helped me to make opencv work on the raspi but with the webcam i am using the frame rate is only around 5 fps which forces me to be in slow motion - nontheless it IS working

I have addedd a daffodil usb sound card to the raspi. Mic works but so far sound only over the raspi audio jack and not over the usb speakers.

As you I sit at my PC and use Windows Remote Desktop to control MRL - by opening port 3389 on my router also Ale was able to connect and with teamviever sessions he showed me how to use opencv and how to look at MRL source code.

good luck and if you find a way to have MRL sound over usb make sure you let us know!



8 years 11 months ago

In reply to by juerg


Great to know that more people are working with MRL on Raspberry PI.  

I have a Raspberry Pi Camera Board but it's not installed on the PI yet. Had isses with my USB soundcard to solve first ;-)

I tested the Speech service on my Raspery Pi using a USB soundcard with both a microphone and a speaker. 

I first had some problems with configuring the soundcard, 

This is the line I use in /etc/modprobe.d/alsa-base.conf

options snd-usb-audio index=0
Two days ago, I tested the AudioCapture service and it worked fine with both the microphone and speakers connected to the USB soundcard..
Today I tested with Speech. It also works fine.
But today I can't get the microphone to work.
'So I think have verified that the problem is with the soundcard configuration, not the MRL. 
I will continue testing different configurations and I hope that I can get everything to work at the same time.