I've a RaspberryPi 3 B running with Raspian on buster (10).
- Power: Official 5.1 V - 2.5 A Power Supply (https://www.raspberrypi.com/products/raspberry-pi-universal-power-supply/)
- Wired Ethernet Connection
- No WiFi, no Bluetooth in use
- USB FlashDrive
- USB ConBee II Zigbee Adapter
- Headless setup with node-red, ziigbee2mqtt, pi-hole and some other services
With that configuration, the system has worked well for several years (!) without any issues apart from 2 SD-card errors.
Some weeks ago, I've added an adaptor with realtek rtl2832u to fetch 433 MHz data. Therefore, I've installed rtl_sdr which pushes 433-Mhz weather-station data to zigbee. In general, this works well, but now, I'm facing sudden crashes of the Raspi.
- Device can be ping'ed
- no ssh connection (timeout)
- no other server connection
- no zigbee communicaton
- a connection via hdmi doesn't show anything
Only solution is to unplugg power supply.
Without finding anything. Additionally I can't find any sign of undervoltage, in particular:
pi@raspberrypi:~ $ vcgencmd get_throttled throttled=0x0
The crash happens after some hours or a week. When unplugging the rtl2832u, everything runs smoothly again.
How shall I investigate this further?
- Powered USB-hub? (Which devices to be connected to this, which directly to the Raspi?, USB 3.0 recommended?)
- other power supply?
- moving zigbee stick and rtl-stick further away (~10 cm)
- anything else?
With open housing systems runs now for 26 h without any issue. Temperature is mostly between 50 and 60 deg celcius with rare spikes up to 62 deg.
pi@raspberrypi:~ $ free -m total used free shared buff/cache available Mem: 923 387 71 3 463 479 Swap: 59330 335 58995
Is there anything bad with theses numbers?
I've added an active usb hub to power the sdr-device. Unfortunately, the crash happend again after 3 days. :-(
Now, I'm wondering whether the issue has actually no causality with adding the stick but with re-arranging my devices (power adaptors, network switch, raspi) within a cable box. Therefore, I've removed the switch from the box (which was the case before adding the sdr-stick) as well as the sdr-stick and the active usb hub. In other words, it's almost the same setup as before.
Now, I'll see if it crashes again. If not, I'll add the sdr stick once again.
Update 2022-04-07 After 5 days of operation I see this memory usage
pi@raspberrypi:~ $ free -m total used free shared buff/cache available Mem: 923 460 115 38 347 376 Swap: 99 99 0
I don't get why total swap changes from last check. available mem slightly decreased.
Now, I've plugged the sdr-stick into the pi, without starting any further software and will monitor this for several days.
I didn't change anything on swap.
pi@raspberrypi:~ $ cat /proc/swaps Filename Type Size Used Priority /var/swap file 102396 102296 -2
This matches to the configuration in
/etc/dphys-swapfile which contains