ArduPilot on Voxl2

[Eric Katzfey]

@TomP It's missing support for that I/O board right now. So you would either have to add that yourself or wait for support to be added.

[TomP]

@Eric-Katzfey When could the support for this be added?

[Alex Kushleyev]

@TomP , if you wanted to try this yourself, a minimal integration of the VOXL2 IO board (M0065) can be done by sending out a single UART packet which contains the PWM output values.

• the function that creates the packet can be found here and it is used in the voxl2_io px4 driver here. You simply provide an array of pwm values (in nanoseconds). This packet is variable length and supports 1,2,4,6, or 8 outputs.
• this would be a minimal implementation, which does not include querying the VOXL2 IO board, checking it's version, etc, which is normally done in our PX4 driver. However, it could unblock your work if you are looking to fly a fixed wing ASAP.
• the packet wrapping function uses the same structure as used for the ModalAI ESC, so that code should already exist in ArduPilot and can be re-used.

Just to add, make sure the latest M0065 firmware is loaded

• https://docs.modalai.com/voxl2-io-user-guide/
• https://docs.modalai.com/voxl2-io-firmware/

The VOXL2 IO board firmware currently operates in one-shot mode pwm, that is for one PWM command packet there will be one pulse generated without a delay. The communication baud rate with the VOXL2 IO firmware is 921600.

Alex

[Eric Katzfey]

@TomP said in ArduPilot on Voxl2:

When could the support for this be added?

Unfortunately, we don't have a fixed date for that support yet. We are striving to support ArduPilot on VOXL 2 by end of this year and that would include support for the IO board. Otherwise I would say keep your eye on the commits going in to AP to see if something comes in sooner.

[TomP]

@Eric-Katzfey That is a manageable period of time for me. We can use it to plan our product roadmap. Thank you very much and keep up the good work.

[TomP]

@Eric-Katzfey Is there an update on the timeline yet?

Best regards
Tom

[TomP]

@Andrew-Tridgell @Eric-Katzfey I wanted to ask again about the current roadmap regarding Arduplane and the IO board for PWM.

Best regards
Tom

[Eric Katzfey]

@TomP We are still shooting for the end of this year. I would like to know what external peripherals you would like to support though. I'm guessing GPS, magnetometer, RC, a PWM based motor ESC, and some servos for flight surface control? Also an airspeed sensor? A distance sensor? What kind of RC are you expecting to use? There are some I/O limitations with VOXL 2 so want to make sure that what you want to build can be supported by what we are putting together.

[TomP]

@Eric-Katzfey We use GPS, compass and the IO board for a PWM-controlled ESC and two servos. We also need two more PWM channels for gimbal control. That's it.

We do not use an RC. The control is purely via MAVLink. Joystick inputs are made via the MAVLink command MANUAL_CONTROL. Data is transmitted via the mobile network.

[Eric Katzfey]

@TomP I have updated the documentation at https://docs.modalai.com/voxl-ardupilot/. The VOXL 2 IO board with up to 4 PWM outputs is now supported and has been tested on a quadcopter with 4 PWM ESCs. You should be able to use this for arduplane now. We are putting together our own fixed wing test platform and hope to begin testing soon.

[Eric Katzfey]

@Eric-Katzfey I will need to add the support for up to 8 PWM outputs on VOXL 2 IO board. Right now it only supports 4. You should be able to do test flights without the gimbal with 4 PWM outputs.

[Eric Katzfey]

@TomP The update to support all 8 PWM outputs from the IO board is now in mainline. You can get it in the latest build posted here: https://firmware.ardupilot.org/Copter/latest/QURT/

[TomP]

Hi,

How can I configure the battery monitor for ArduPlane on the VOXL2-Mini?
Which value do I have to enter for BATT_MONITOR and which values for BATT_I2C_ADDR and BAT_I2C_BUS?

The "VOXL 2 Mini Power" transmits the current and voltage measurement data via I2C.

Best regards,
Tom

[Eric Katzfey]

@TomP It should just scan the available I2C ports and automatically detect the VOXL 2 mini power module if it has been connected. Is it not detecting it?

[TomP]

@Eric-Katzfey No, this is not detected. The configuration does not seem to be correct either. The parameter list mentions "Analog Voltage and Current" and corresponding pins.
Here is a screenshot:

[TomP]

Hi,

There is another problem. The PWM board does not output PWMs. I have also measured this with an oscilloscope. According to SERVO_OUTPUT_RAW, however, the FC should output PWM values.

Do I have to set another parameter in Arduplane so that the VOXL 2 I/O Expander Board is controlled correctly?

I use the VOXL2-Mini J19 connector: GND, pin 7, pin 8 and VREG_3P3V_RC for the power supply.

Here is my setup:

[Eric Katzfey]

@TomP Okay, yes, sorry, you need to set BATT_MONITOR to 21 for INA2xx and need to set BATT_I2C_BUS to 1 for that power monitor to come up. I'll investigate the PWM issue.

[TomP]

@Eric-Katzfey The battery monitor works. Thank you very much! I'm sure the PWM will also work and then it's off to the test flight.

[Eric Katzfey]

@TomP What are the settings of all the SERVO(x)_ params?

[Eric Katzfey]

@TomP If you set the SERVO(x)_FUNCTION parameters according to this: https://ardupilot.org/plane/docs/servo-functions.html#overview do you get any PWM output?