The TFLuna in I2C communication mode is unique among the Benewake family of LiDAR products in at least two ways:
- The communications mode (UART/U2C) is set by the voltage level of Pin #5 rather than a command; and
- The internal device registers of the device can be addressed directly.
This library is not compatible with any other Benwake LiDAR device in I2C mode. In serial (UART) mode, the TFLuna is largely compatible with the TFMini-Plus and is therefore able to use that library.
This library calls the Arduino standard I2C/Two-Wire Library.
The getData( dist, flux, temp, addr) function passes back three, signed, 16-bit measurement data values and sends an unsigned, 8-bit I2C address in the range of 0x08 to 0x77 (8 to 119). A correct addr value must always be sent. If the function completes without error, it returns 'True' and sets the public, one-byte 'status' code to zero. Otherwise, it returns 'False' and sets the 'status' code to a library defined error code.
Measurement data values are passed-back in three, 16-bit, signed integer variables:
– dist Distance to target in centimeters. Range: 0 - 1200
– flux Strength or quality of return signal or error. Range: -1, 0 - 32767
– temp Temperature in hundreths of degrees Celsius. Range: -25.00°C to 125.00°C
For convenience and simplicity, a getData( dist, addr) function is included. This function passes back distance data only.
Other commands are explicitly defined and are broadly separated into "Set" that modify a device parameter value and and "Get" commands that examine a parameter value. All commands take the form of a function name followed by one or two parameters that are always the unsigned, 8-bit I2C address of the device and sometimes a register value before the address. If the function completes without error, it returns 'True' and sets a public, one-byte 'status' code to zero. Otherwise, it returns 'False' and sets the 'status' to a Library defined error code.
Explicit commands:
– Get_Firmware_Version - pass back array of 3 unsigned 8-bit bytes
– Get_Frame_Rate - pass back unsigned 16-bit integer of Frame-Rate in frames per second
– Get_Prod_Code - pass back 14 byte array of ASCII coded serial number
– Get_Time - pass back unsigned 16-bit integer of device clock in milliseconds
– Set_Frame_Rate - send unsigned 16-bit integer of Frame-Rate in frames per second
– Set_I2C_Addr - send unsigned 8-bit byte of the new address
– Set_Enable - turns ON device light source
– Set_Disable - turns OFF device light source
– Soft_Reset - reset, reboot and restart
– Hard_Reset - restore factory defaults
– Save_Settings - save changes
– Set_Trig_Mode - set device to sample once when triggered
– Set_Cont_Mode - set device to continmuously sample
– Sample_Trig - trigger device to sample once
In I2C mode, the TFMini-Plus functions as an I2C slave device. The default address is 0x10 (16 decimal), but is user-programable by sending the Set_I2C_Addr command and a parameter in the range of 0x07 to 0x77 (7 to 119). The new address requires a Soft_Reset command to take effect. A Hard_Reset command (Restore Factory Settings) will reset the device to the default address of 0x10.
Some commands that modify internal parameters are processed within 1 millisecond. But some commands that require the MCU to communicate with other chips may take several milliseconds. And some commands that erase the flash memory of the MCU, such as Save_Settings and Hard_Reset, may take several hundred milliseconds.
Frame-rate and most other parameter changes should be followed by a Save_Settings command or the values may be lost when power is removed. With the TFLuna, commands are available to examine the value of various device paramters such as frame rate, trigger mode, power mode, threshold values, internal timer, error and production code.
Also included in the repository are:
● An Arduino sketch "TFLuna_example.ino" is in the Example folder, as well as a simplified version of the example code, "TFLuna_simple.ino".
● Recent copies of manufacturer's Datasheet and Product Manual are in the Documents folder.
All of the code for this Library is richly commented to assist with understanding and in problem solving.