These are chat archives for PX4/Hardware

5th
Jul 2016
Lucas Åström
@Jinxit
Jul 05 2016 08:19
if I have a pixhawk and an offboard computer (tegra x1 to be specific) that I want to power with the same battery, how should the wiring be set up?
can I just connect them in parallel? do I need to connect common ground?
can I communicate over USB?
Andrej Pangercic
@andrejpan
Jul 05 2016 14:00
@Jinxit not sure for powering, because I am using a Pixracer, but usb communication is not advised. At QGC control you have you have parameter CBRK_USB_CHK(PX4 stack) which will enable usb communication, but it is on your own risk. You should rather have UART-UART communication.
And some basics on the overall TX1, which you should be familiar with before attempting any of this: http://elinux.org/Jetson_TX1
Sander Smeets
@sanderux
Jul 05 2016 15:23
Does anyone know if http://store.jdrones.com/digital_airspeed_sensor_with_compass_p/senairmag03kit.htm suffers from the same voltage problem as the regular digital airspeed sensor?
Sander Smeets
@sanderux
Jul 05 2016 15:29
Also, i'm currently testing the Eagle Tree Airspeed MicroSensor V3, after calibration it calculates a SENS_DPRES_OFF of around 1500. From other logs i have seen the regular airspeed sensors range between 20-100 on this. The registered airspeed is MUCH lower then the actual speed (it registers 15m/s when it's actually flying around 22m/s). Anyone have any experience with that?
Nathaniel Noussias
@cosmonate
Jul 05 2016 15:30
I think the AUAV sensor is suppose to have the logic level fix, not sure about the others. http://www.auav.co/product-p/i2c-as.htm
Sander Smeets
@sanderux
Jul 05 2016 15:30
@cosmonate yes, i have one of those too, i just like the elimination of the i2c splitter on that jdrones one.
Karanvir Panesar
@kPanesar
Jul 05 2016 19:46
@dogmaphobic @DavidIngraham I'm using 12 gauge wire on the batteries and 13 gauge wire on the power module (just the standard that it comes with). The total wire length from the start of the battery to the power module sensor is about 7 inches. The wires don't get warm either. I also swapped the cable going from the power module to the Pixhawk and noticed no change in behavior. I changed the scale so that it reads the proper voltage at hover throttle but that just reverses the problem (I get higher voltage at idle). What do you think it might be?
MrPeppow
@MrPeppow
Jul 05 2016 22:23
Hi
i just got my px4flow and im not getting any Sonar output
im connected via i2c and both the distance and the integrated distance keep beeing zero.
the sonar is active, i can hear a silent buzzing from it.
i got a chinese one since the usual one is nowhere in stock
groundcontrol shows the same thing, firmware is the newest stable one
solderbridge is connected to 5V