Posts made by Jetson Nano

@Vinny My bad, I guess question 1 is moot. Just realised that MH does not accept power over VBUS.

@Vinny Thanks a lot for the detailed response. You made it very clear. However, My confusions started as I am planning on flying my system using variant "-2" on VOXL 2 only due to space constraints to use "-3", although "-3" is the ideal choice.
Hence, my last set of doubts are:

1. Can I power MH over VBUS if I am not using any other downstream peripherals? Is it reliable / advisable ?
2. Is there a difference in data transfer rates using "-2" over "-3" ?
3. Can I go ahead and use two of "-2" variants - One for air and one for ground and expect same results as using "-3" for air?

Thank you @Eric-Katzfey ,for the confirmation with respect to the approach. Can you help me the code, maybe with providing a sample code.

I wrote a code to receive the data but the code was not connecting the Flight controller. I am providing the code here, Can you verify the code.

from pymavlink import mavutil
import time
import logging

logging.basicConfig(level=logging.INFO)

# Connection string for voxl-mavlink-server
connection_string = 'udp:192.168.8.1:14558'

# Function to send a heartbeat message
def send_heartbeat(mavlink_connection):
    mavlink_connection.mav.heartbeat_send(
        mavutil.mavlink.MAV_TYPE_GCS,         # Type: Ground Control Station
        mavutil.mavlink.MAV_AUTOPILOT_INVALID,  # Autopilot: Not a specific autopilot
        0,                                   # Base mode
        0,                                   # Custom mode
        mavutil.mavlink.MAV_STATE_ACTIVE     # State: Active
    )
    logging.info("Heartbeat sent.")

def main():
    try:
        logging.info(f"Connecting to {connection_string}...")
        # Establish MAVLink connection
        mav = mavutil.mavlink_connection(connection_string)

        # Send an initial heartbeat to register as a GCS
        logging.info("Sending initial heartbeat...")
        send_heartbeat(mav)

        # Wait for heartbeat from the flight controller
        logging.info("Waiting for heartbeat from the flight controller...")
        mav.wait_heartbeat(timeout=10)
        logging.info(f"Heartbeat received! System_ID: {mav.target_system}, Component_ID: {mav.target_component}")

        # Request RC_CHANNELS data stream at 1 Hz
        mav.mav.request_data_stream_send(
            mav.target_system,
            mav.target_component,
            mavutil.mavlink.MAV_DATA_STREAM_RC_CHANNELS,
            1,  # Stream rate in Hz (1 Hz)
            1   # Enable the stream
        )

        # Periodically send heartbeats to keep the connection alive
        last_heartbeat_time = time.time()

        while True:
            # Send a heartbeat every 1 second
            current_time = time.time()
            if current_time - last_heartbeat_time > 1:
                send_heartbeat(mav)
                last_heartbeat_time = current_time

            # Listen for incoming messages
            msg = mav.recv_match(blocking=True)
            if msg:
                msg_type = msg.get_type()
                logging.info(f"Received message: {msg_type}")

                # If it's an RC_CHANNELS message, print the values
                if msg_type == 'RC_CHANNELS':
                    logging.info(f"Channel 1: {msg.chan1_raw}")
                    logging.info(f"Channel 2: {msg.chan2_raw}")
                    logging.info(f"Channel 3: {msg.chan3_raw}")
                    logging.info(f"Channel 4: {msg.chan4_raw}")

    except KeyboardInterrupt:
        logging.info("Exiting program.")
    except Exception as e:
        logging.error(f"An error occurred: {e}")

if __name__ == "__main__":
    main()

The following is the output I got and it was stuck here and not moving forward.

INFO:root:Connecting to udp:192.168.8.1:14559...
INFO:root:Sending initial heartbeat...
INFO:root:Heartbeat sent.
INFO:root:Waiting for heartbeat from the flight controller...
INFO:root:Heartbeat received! System_ID: 0, Component_ID: 0

@Vinny Thanks for reverting. I'm little confused now. So when using "-2" variant with the red connector, can the peripherals be powered?

Hi @Eric-Katzfey, I was thinking another approach, where we can use pymavlink to get the RC_channel data. Any inputs to the mentioned approach, is it feasible?

@Vinny Thanks for reverting. Yes, as you mentioned there are 8 channels of PWM. Apart from using 4 channels for controlling 4 Motors on quadcopter, I would like to use rest of the available ones to control neopixel, an external led strip using one of the AUX outputs.

But as per the documentation, I'm not able to see how to access the AUX outputs. Could you please help?

@Vinny Thanks. Also I have another doubt. My main use-case for moving to a different module was considering a scenario in my custom air frame where due to space constraints I can't place the MH module on the J3 port. In this case, I'm planning to power the MH module from ModalAI seperately at the rated voltage from the main power line and for communication with VOXL2, I'm planning to rely on the USB peripherals available on the MH module through 4-pin 4-pin JST Type connector heads.

In simpler words, can I use the MH module without J3 port(i.e. the ground unit which can be connected to Laptop) as air unit on the system as well?

@modaltb, could this be done with VOXL2 directly or only using FlightCore V2 instead of relying on PX4 IO board? If yes, could you please guide me with a rough setup of this configuration?

@Vinny I have a doubt. Can I use MH module on a different light weight carrier instead of the once provided by ModalAI and have the UART line connected to VOXL2?

I also looked into this topic also for reference, link

Would this type of configuration work?

@tom @Alex-Kushleyev @Vinny Any Help would be much appreciated.

@tom yes, the message is coming from external flight controller, Flight core v2. Now can you share how to double check if the RC message is set up to forward to voxl-mavlink-server from Flight Core (if not, how to enable it) and how to actually read that message?

@tom This is the output I get,

Hey!

I have been through the Documentation of FlightCoreV2. Apart from availability of PWM Main Pins, is there availablility of PWM AUX Pins as well? If yes, how do I enable and use them?

I'm planning to intergrate Gimbal Camera with Flight CoreV2 on PX4, hence would be needing PWM AUX Pins for the same.

@tom As per your response on shifting to voxl-inspect-mavlink mavlink_offboard, I see that even in mavlink server documentation from ModalAI that service pipeline is not listed. Is it that something that has to be explicitly be enabled somewhere?
Even as per the documentation, I dont see this service pipeline listed.

@Alex-Kushleyev I currently use, VOXL2 USB 3.0 Expansion Adapter connected to VOXL2. From the UART7 port of the Expansion Adapter I have connected to 6-PIN Telemetry1 Port in Flight Core V2.

My connection is similar to this,

As you mentioned earlier, I'm establishing connection through port /dev/ttyHS1. When I run the cat command to read the messages from this port, I get garbled data as below,

.

I'm not exactly clear when you mean if I have tried connecting to VOXL2 from QGC and access the Flight Core V2. Few things I have tried is,

• Connecting to FlightCore V2 by connecting to Wifi of VOXL2. I also have a Wifi setup on VOXL2, which also acts as my Telemetry line. From QGC I connect to this local network to access FC data and PX4 parameters on Flight Core V2.

• I have tried and tested few mavlink message commads which communicate with PX4 directly for C2C.

@Alex-Kushleyev
yes the voxl-mavlink-server is running, I had checked it.

I am following this documentation for FC connections.

[link](https://docs.modalai.com/flight-core-connections/#:~:text=Using the MCBL-00010](%2F,which can lead to issues.)

@Alex-Kushleyev @tom
Guys I checked what you guys mentioned.

The en_external_uart_ap is set to True, but when I run the command voxl-inspect-mavlink mavlink_offboard , the terminal is showing waiting for pipe to connect and not showing anything else.

Adding to the previous point there is no mavlink_offboard showing up.

@tom @Alex-Kushleyev thanks guys. I will check it and get back to you with the result.

thanks @tom for reverting back. I had already tried it and I was not able to see any RC channel data. listener function was not working.
The issue is I am not able to see the RC channel changes. Can you help me out how am I supposed to get the RC changes.

@Alex-Kushleyev I am using flight core v2 as external FC. Due to which i am getting error message when i run the command px4-listener.

Can you help me out here. how to get the data when we use external FC.