[Solved] Zero sensor values

All seems good! At least the sensors demo now works for me.

Sorry for the delay. I physically broke (in two) the uSD card in my Pi3 when I accidentally pushed down on it while trying to remove the Matrix. Naturally, I had no backup and no spare uSD cards. Had to go shopping then reimage, reinstall and recreate everything.

We all know the moral to this story… Keep live backups! I now keep a thumbdrive in my Pi3, and run the following after any significant system change.

$ sudo mount /dev/sda1 /mnt && sudo dd if=/dev/mmcblk0 bs=1M | gzip /mnt/${HOSTNAME}.$(date +%s).img.gz && sudo umount /mnt

Hi @BobC, great to hear that !

Hope @rkeithbeal, @analog71 and others users could test this too.

@BobC @yoelrc88 sorry guys I’ve had no time to look at this for a while. Day job is keeping me too busy. Will try give it some time over the holidays.

@yoelrc88 @BobC @rkeithbeal Got some time to play with this today. All working now or at least I can run the HAL demos provided. The “mic_demo” still returns “0” for me but the “mic_energy” demo seems to work fine in that the LEDs light up RED in response to sound. The “sensor_status” program returns the following:

IMUY:-1.6e+02° IMUR:-3.4° IMUP:-0.93°
HUMI:29% HTMP:34°C UVID:33
PRSS:1.0243e+05 PrAL:-91.75 PrTP:32.375
MCU :0x10 VER :0x161026

And the “sensor_demo” program:

yaw = -161.916° roll = -0.856716° pitch = -0.83855°

humidity = 28.3058 %
temperature (from humidity sensor) = 35.0635 °C

pressure = 102412 kPa
altitude = -90.25 meters
temperature (from altimeter) = 33.25 °C

UV = 22.0187

MCU ID = 0x10
MCU version = 0x161026

Leave it there for today. HW seems to be functioning. Now I need to figure out how to access the sensors from a Python program say on the RPI in order to use the HW for something :slight_smile:

@BobC @yoelrc88 @rkeithbeal I guess I had to check the mics some more. I followed the instructions outlined here and it seems to work.

I converted one of the files to .WAV and played back. The recording is audible but I needed to max the ALSA PCM gain to 4dB. Also a fair amount of noise in the recording when I played back.

sorry seems to be known issue with noise

Hi @analog71,

Did you find how to get clear audio? In the post you mentioned the final conclusion is here : Noise in sound recording - #3 by ricardog

The problem was malos running at the same time that the user app :

Let us know your progress con this !


Hi @yoelrc88
I haven’t tried yet. How do you kill this Malos process?
Can I remove this Malos and just use the low level drivers to directly access the HW via HAL?

There is a description here (Overview diagram seems to have been deleted?)


Yes @analog71, one valid option is just use HAL as a lower layer to access the data from the MATRIX Creator. As you said in that case you dont need MALOS or MOS. I recommend you to do a clean install from scratch just using HAL.

to kill malos you can try:
sudo pkill malos

Let us know is you have any problem with HAL


I received my matrix voice two weeks ago and am a little stuck now…
I know this thread is already solved, but I think I have the described problem also and already tried everything that was suggested here.
What works:

  • LEDs
  • MIC Demos (HAL)


  • All sensor (temperatur, humidity, …) values 0
  • MCU ID = 0x0
  • MCU version = 0x0

I’ve already tried different power supplies, but with no success.
Is anyone facing the same problem?

The Matrix Voice has no sensors, only the Creator…

@loom aaah, thanks a lot for your instant reply!
Seems like I was a little confused here :smiley:, :see_no_evil:
So the positive thing is: everything works as expected then :wink: