Alex,
Regarding the ring buffer issue...
We checked our code and the only two functions we use are voxl_uart_init and voxl_uart_write, which from the voxl_serial.py script, we should be find to use.
For the voxl_uart_write function, we are currently passing (SLPI_QUP2_UART, tx_buf, packet_length) where
uint8_t tx_buf[128];
int32_t packet_length = qc_esc_create_rpm_packet4_fb(rpm0, rpm1, rpm2, rpm3, led, led, led, led, cntr, tx_buf, sizeof(tx_buf));
Aside from this, we are not interacting with the ESC at all, so the error must be coming from one of these functions being called.
Do you have any ideas for us by chance?
Thank you for your insights and time!

@Alex-Kushleyev

Regarding question 2, you are right, we did not use px4 before this and ran a custom node on the CPU. But now, we need to do some outdoor flights with GPS, and therefore need the voxl-px4.
Do you think there is any other way we can do this? For us to be able to get vehicle odometry using GPS without PX4?

Regarding question 1,
I confirmed that the voxl-px4 is infact disabled and the voxl-esc scan successfully finds 4 ESC's. I wonder if this is related to the voxl_uart_write function call?

Thank you!

Hi Alex,

We are currently trying to get RPM control working along with the new SDK in ROS2 and have run into a couple issues.

1. We followed your suggestion and included the UART library onto the drone. After building successfully, we tried sending RPMs through our ROS2 rpm interface and got the error:

"ERROR:   Received error from ring_buf_push in p_slpi_receive_callback: ERR_NO_SPACE"

Do you have any suggestions on how we might fix this issue?

Additionally, we had a question regarding the UART and px4 interfaces.
2) Is it possible to run both the UART voxl esc and px4 in parallel? Our idea was to disable the px4 ESC driver manually when px4 first starts up but were not able to use the UART successfully, with the error:

ERROR:   voxl_uart_write: Bus '12' is not initialized

If you have any insights or suggestions, we would greatly appreciate it.
Thank you!

Nishanth