How to control motor pwm or moving of RPLIDAR A1 in matlab

[wnghdwnsrl]

Hello, I 'm using RPLIDAR A1 for project in matlab 2019b
but there are two problem using it.

1. I can't control RPLDIAR A1 pwm by using SetMotorPWMRequestRPLIDAR() or SetLidarSpinSpeedRequestRPLIDAR().
   How can i control RPLIDAR A1 pwm another way?( I couldn't understand well ismet55555's issue)
2. There was a problem using RPLDIAR with Dynamixel MX-64 motor to make 3d scan. When i make RPLIDAR scan while MX-64 tilt repeatedly, it looks odd.
   The code is when MX-64 move, next get points of PRLIDAR by using GetScanDataResponsePRLIDAR(), From the beginning it just get next data after first 360 number of data, not the data after MX-64 move.
   I just thought it could solve by making this operate like RPLIDAR scan just once 360points and MX-64 move repeatedly.
   Is there any way to control RPLIDAR stop and turn agian in matlab?

[lebarsfa]

Hello,

1. I am not sure if there is a software way to control the speed of the A1, in my comment S3 RPLIDAR Does Not Respond to Changes in Motor PWM  #5 (comment) I was not mentioning the A1 because of the comments in https://github.com/Slamtec/rplidar_sdk/blob/504a2e5dfb544124c3edbb94419f866ed274b99c/sdk/sdk/include/rplidar_driver.h#L180, you might need to ask SLAMTEC if there is an undocumented way to do that...
2. Maybe try StopMotorRPLIDAR() and StartMotorRPLIDAR() that I just added in https://github.com/ENSTABretagneRobotics/Hardware-MATLAB/releases/download/v1.5.3/hardwarex_with_3rd_support.zip (not tested), but I am not sure this would be a viable workaround...

[wnghdwnsrl]

Thank you for your comment!

StartMotorRPLIDAR() and StopMotorRPLIDAR() function in hardwarex_with_3rd_support file are working.

Thank you for your help again

[wnghdwnsrl]

Hello, I used StartMotorRPLIDAR() and StopMotorRPLIDAR() functions well
But there is another problem using two functions.
When I stopped motor and started RPLIDAR A1 again, GetScanDataResponse() didn't work and matlab had forcely ended. (exit all pages).
Is there any solutions about this problem?

[lebarsfa]

Maybe before the StopMotorRPLIDAR(), we need StopRequestRPLIDAR(), and after StartMotorRPLIDAR(), we need StartScanRequestRPLIDAR() before calling GetScanDataResponse().
If it does not work, in test_rplidar.m, check

Hardware-MATLAB/test_rplidar.m

Lines 7 to 16 in e4512bc

	% If bStartScanModeAtStartup to 0 in RPLIDAR0.txt...
	%[result] = ResetRequestRPLIDAR(pRPLIDAR)
	%pause(2)
	%[result] = GetStartupMessageRPLIDAR(pRPLIDAR)
	%[result] = StopRequestRPLIDAR(pRPLIDAR)
	%[result, ModelID, HardwareVersion, FirmwareMajor, FirmwareMinor, SerialNumber] = GetInfoRequestRPLIDAR(pRPLIDAR)
	%[result, typicalscanmodeid] = GetTypicalScanModeRPLIDAR(pRPLIDAR)
	%[result, scanmodeids, scanmodeuspersamples, scanmodemaxdistances, scanmodeanstypes, scanmodenames] = GetAllSupportedScanModesRPLIDAR(pRPLIDAR)
	%[result] = SetMotorPWMRequestRPLIDAR(pRPLIDAR, 660)
	%[result] = StartScanRequestRPLIDAR(pRPLIDAR)

where it is suggested that if you set bStartScanModeAtStartup to 0 in RPLIDAR0.txt you need to uncomment those lines. Maybe you will need to follow a similar logic after the StartMotorRPLIDAR()...

[wnghdwnsrl]

Thank you, it works well with no errors. but i have one more question.
when I stop and restart motor and move RPLIDAR A1 scan area, then it scans just before data( not new area). I think i need to clear buffer to scan new data.
If I want to clear RPLIDAR A1 buffer, Is there any solution that you can advise?

[lebarsfa]

I just added ClearCacheRPLIDAR() (which calls clearNetSerialRxCache() from the SLAMTEC C++ SDK), see v1.5.5 release : https://github.com/ENSTABretagneRobotics/Hardware-MATLAB/releases/tag/v1.5.5. Otherwise, I do not see an obvious way to solve this problem...