RPLidar A2 not initiate....some times

alberto.munizaga · February 4, 2022, 12:33pm

Hi I have a RPLIdar A2M8, and im having problems with it, may be some one face the same. I have setup the A2M8 on the cube as is described on the wiki. The issue is some times works, some times dont… Always spining, but some times on the MP radar I see nothing and Proximity Sensor warning on the mesage window, then reboot and I get data…, other times reboot and no data again… I thought the Lidar was damage, so to give it a try I have connected to the PC with the USB interface it come (no cube), and always get data with the PC software, works perfect. I have set up a delay boot for the cube thinking maybe the lidar boot too fast, but the result is the same. I have try it on a black and orange cube.

Any idea why my rplidar do that? Thanks!

ppoirier · February 4, 2022, 2:12pm

Hello,

How is the Lidar powered ?
We generally recommend a dedicated Ubec with common ground with FC

alberto.munizaga · February 4, 2022, 2:24pm

Thanks, yes all of that are done, external UBEC and common GND

ppoirier · February 4, 2022, 2:47pm

When its not responding,
If you do a Warm Boot : Mission Planner - Actions - Preflight_Reboot - Yes
Does it reappears ?

alberto.munizaga · February 4, 2022, 2:50pm

I havent try that, but we do the reboot from this screen, i dont know if its the same you describe.

ppoirier · February 4, 2022, 3:04pm

Yes it works but I prefer that ons as iI can switch to Message reading and then connect

alberto.munizaga · February 4, 2022, 3:06pm

thanks!, ok I will try and let you know.

ppoirier · February 4, 2022, 3:09pm

And if you want to push investigation, there is a debug switch on code… but this requires building code with WAF

github.com

ArduPilot/ardupilot/blob/master/libraries/AP_Proximity/AP_Proximity_RPLidarA2.cpp#L36

    
      
          *
          */
          
          
#include "AP_Proximity_RPLidarA2.h"
          
          
#if HAL_PROXIMITY_ENABLED
          #include <AP_HAL/AP_HAL.h>
          #include <ctype.h>
          #include <stdio.h>
          
          
#define RP_DEBUG_LEVEL 0
          
          
#if RP_DEBUG_LEVEL
           #include <GCS_MAVLink/GCS.h>
           #define Debug(level, fmt, args ...)  do { if (level <= RP_DEBUG_LEVEL) { gcs().send_text(MAV_SEVERITY_INFO, fmt, ## args); } } while (0)
          #else
           #define Debug(level, fmt, args ...)
          #endif
          
          
#define COMM_ACTIVITY_TIMEOUT_MS        200
          #define RESET_RPA2_WAIT_MS              8

alberto.munizaga · February 7, 2022, 2:25am

Hi, just an update.

I dont know why, but the sensor WONT WORK or be realiable on Serial 1 or 2.

I put it on Serial4 and works at the first try, and no more problems. Didnt try serial3 becauase I have the GPS there.

Tested on Black and orange cube, 4.1.3 FW

Hope this can be useful for future users.

Thanks for your help!