Product Introduction

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The startScan() function will start a background worker thread to receive the

measurement scan data sequence sent from RPLIDAR asynchronously. The

received data sequence is stored in the driver’s internal cache for the

grabScanData() function to fetch.

User programs can use the grabScanData() function to retrieve the scan data

sequence previously received and cached by the driver. This function always

returns a latest and complete 360-degrees’ measurement scan data sequence.

After each grabScanData() call, the internal data cache will be cleared to ensure

the grabScanData() won’t get duplicated data.

In case a complete 360-degrees’ scan sequence hasn’t been available at the

time when grabScanData() is called, the function will wait until a complete scan

data is received by the driver or the given timeout duration is expired. User

programs can tune this timeout value to meet different application requirements.

Note: the startScan() and stop() functions don’t control the scanning motor

of the RPLIDAR directly. The host system should control the scanning motor to

rotate or stop via the PWM pin.

Please refer to the comments in the header files and the implementation of SDK

demo applications for details.

Retrieving Other Information of an RPLIDAR

The user program can retrieve other information of an RPLIDAR via the following

functions. Please refer to the comments in the header files and the implementation

of SDK demo applications for details.

Figure 3-3 RPLIDAR Functions related to Retrieving Other Information Operation

Function Name

Brief description

getHealth()

Get the healthy status of an RPLIDAR

getDeviceInfo()

Retrieve the device information, e.g. serial number,

firmware version etc, from and RPLIDAR

getFrequency()

Calculate an RPLIDAR’s scanning speed from a

complete scan sequence.

checkExpressScanSupported()

Check whether the RPLIDAR supports Express Scan

mode

getSampleDuration_uS()

Get the the single measurement duration in standard

scan mode and express scan mode respectively. The

unit is micro second.