Nightly 2020-3-23

Note: nightly images are for testing purposes, the changes are not necessarily unstable or completely untested, but they are still changes, and they may affect the stability of the system. They have not been tested with every piece of hardware or configuration.

There are significant changes in this release, it really is a testing/experimental release, be careful

We now have images based on Raspbian Buster, which allows us to support new hardware like the Pi4B. While you can use the Buster image on any Pi model, it has not been tested as much as the old Raspbian Stretch based image.

People who should continue to use the Stretch release image for now:

• You need telemetry protocols other than Mavlink
• You want to use the old OSD
• You use a Pi Zero, Pi 3b, or Compute Module 3
• You need to use the 2nd camera switching system

People who must use the Buster release image:

• You have a Compute Module 3+, or Pi4b

Known issues

• The rtl8812 driver for 5.8ghz wifi cards was unintentionally left out of this buster image
  • The problem is fixed already, 8812 cards will be working in the next nightly image (2020-3-26)
• The total distance display in OSD may drift or accumulate more than it should
  • It is likely to be replaced with a GPS coordinate calculation instead of the current speed approximation
• When QOpenHD is running on the ground station, downlink RSSI might show -100dBm all the time
• When 3x Atheros cards are connected on the ground, the video RSSI might show -126 all the time
  • Unconfirmed, being investigated
• Video may stutter or freeze when ground recording to SD card is enabled with VIDEO_TMP=sdcard
  • This is an old problem, the settings file has had a note about it for probably a year or more
  • A temporary solution is to use VIDEO_TMP=memory instead
  • Will be resolved soon by separating the recording system from the rest of the video pipeline so it can't affect live flight
• Video may freeze on 8812 cards in certain cases
  • Unconfirmed, being investigated
• When using the buster image the old OSD is not available, QOpenHD is always enabled
  • The old OSD uses OpenVG, which is not supported on the pi4 at all
  • If someone wants to look at adding an OpenVG compatibility layer, it might be possible to get it to work, ask in telegram if you want to help
• 2nd camera might not work on the buster image
  • This is because of a bug in the version of gstreamer-omx-rpi packaged in Raspbian Buster
  • An easy workaround is available but has not been added yet
• GNUplot is not being installed on the Buster image, it pulls in 670MB worth of other packages and fills the SD card
  • This affects the telemetry charts that are saved when you plug in a USB drive after flying
  • GNUplot itself should be installable separately, so this is a temporary issue

Changes

• Add buster image for Pi4B support
  • Note that buster is not as tested as stretch, be careful with it
• Put ethernet connection messages back on OSD
• Don't cut bitrate in half for IMX290 camera anymore, not necessary
• Fix detection of HDMI-CSI board for bitrate adjustment
• Add preliminary LTE and Zerotier video support on air side (#281, from Luke/pilotnbr1)
  • Talk to Luke in Telegram if you're interested in testing this
• Fix detection of cameras on Stereo Pi
  • You still need to add the dt-blob.bin file from the Stereo Pi website and put it on the boot partition (this will be automated soon)
  • Running both cameras is not fully tested yet, there are several other fixes that will be added in the next release
• Fix telemetry transmission for Vector Open Telemetry
  • This is untested and may not be the only fix needed to make VOT work
• Put Open.HD version files in /boot partition
  • Makes it easier to check which image is burned to an SD card by connecting it to any computer with a card reader
• Update QOpenHD to nightly-2020-3-23
  • Includes a long list of fixes, see release notes
• Internal changes
  • Use BCM numbering scheme in cameracontrolUDP, needed for Compute Module 3/+

Test notes

• Report problems with 2nd cameras, camera switching, CM3+, Pi4B
• Report problems with GPIO use or Mavlink telemetry
• openhdvid has additional latency in certain situations, be careful if you are testing it (don't fly with it yet)