Mavros: Official method to configure message rate

You can’t configure message rates from QGC.

On Jun 6, 2015, at 7:38 PM, y22ma [email protected] wrote:

Hey guys,

Just wondering what is currently the offical method to configure message rate? I was hoping to configure IMU message rate to around 200Hz on the Telem port 2 on the Pixhawk.

I did see this ticket https://github.com/mavlink/mavros/issues/178, but I could not find the documentation on QGC for rate configuration as mentioned by @LorenzMeier https://github.com/LorenzMeier.

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Reply to this email directly or view it on GitHub https://github.com/mavlink/mavros/issues/305.

@DonLakeFlyer thanks for the response. So currently the only way to do it is to modify the rc.usb and reflash? I'm assuming that the stream API is still deprecated.

Cheers,

Yan

I don’ t know the answer as to how to do it from the firmware side.

On Jun 6, 2015, at 8:40 PM, y22ma [email protected] wrote:

@DonLakeFlyer https://github.com/DonLakeFlyer thanks for the response. So currently the only way to do it is to modify the rc.usb and reflash? I'm assuming that the stream API is still deprecated.

Cheers,

Yan

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Reply to this email directly or view it on GitHub https://github.com/mavlink/mavros/issues/305#issuecomment-109680623.

@y22ma you don't need reflash, use extras.txt on SD card.

Got it. I just need to add, for example:

mavlink stream -d /dev/ttyACM0 -s HIGHRES_IMU -r 100

to increase the rate for IMU messages to 100Hz?

So I added a extras.txt on /etc/ on the SD card, and here's what I have:

#!nsh
#
# USB MAVLink start
#

mavlink start -d /dev/ttyS6 -b 921600
# Enable a number of interesting streams we want via USB
mavlink stream -d /dev/ttyS6 -s PARAM_VALUE -r 300
mavlink stream -d /dev/ttyS6 -s MISSION_ITEM -r 50
mavlink stream -d /dev/ttyS6 -s NAMED_VALUE_FLOAT -r 10
mavlink stream -d /dev/ttyS6 -s OPTICAL_FLOW_RAD -r 10
mavlink stream -d /dev/ttyS6 -s VFR_HUD -r 20
mavlink stream -d /dev/ttyS6 -s ATTITUDE -r 20
mavlink stream -d /dev/ttyS6 -s ACTUATOR_CONTROL_TARGET0 -r 30
mavlink stream -d /dev/ttyS6 -s RC_CHANNELS_RAW -r 5
mavlink stream -d /dev/ttyS6 -s SERVO_OUTPUT_RAW_0 -r 20
mavlink stream -d /dev/ttyS6 -s POSITION_TARGET_GLOBAL_INT -r 10
mavlink stream -d /dev/ttyS6 -s LOCAL_POSITION_NED -r 30
mavlink stream -d /dev/ttyS6 -s MANUAL_CONTROL -r 5
mavlink stream -d /dev/ttyS6 -s HIGHRES_IMU -r 100
mavlink stream -d /dev/ttyS6 -s GPS_RAW_INT -r 20

# Exit shell to make it available to MAVLink
exit

I changed the HIGHRES_IMU rate to 150, and changed the port to ttyS6 to publish data through the SERIAL4 port. I also connected the RTS and CTS lines, and the data is coming through faster, but only at around 124hz. Would that be the upper bound of what the device is write?

Anyways, the original question has been resolved. Recommend closure to this issue.

@y22ma
I want to change the message rate with PX4 firmware. Does it mean we have to add the extras.txt on /etc/? The PX4 firmware will read the extras.txt on the /etc/ getting configuration parameters? Anything else we need to do except adding the extras.txt?
Thanks!