Based on budryerson original code I have made some changes and new sketches to change the com mode from UART to I2C and back via Arduino UNO.
The main purpose of this was to easily allow changing mode for use in Ardupilot and PX4 with out having to understand the code.
These files have been tested on Arduino UNO and do as follows.
Simply reads the TFMini Plus when in serial mode, no changes made. this uses pins 0 and 1 as per the Uno serial ports.
This will change the communicationd mode from UART to I2C on the default address of 16
This is allow you to change the I2C address then read the I2c output, this is configured for Pins A4 (SDA), A5 (SCL) as per wire.h.
This sets the port mode back from I2C to serial.
You Will need to install the TFMPLUS and TFMPI2C Librarys for use these files, these can be found in the libary manager or they are also included here too.
Verify and upload serial read sketch to arduino, reboot. Connect via correct ports for communication type (for serial to I2C connect on pins 0 & 1) Power on and open serial console from tools menu and verify connection by seeing data from sensor. Verify and upload SET I2C sketch to Arduino, reboot. Power on and open serial console from tools menue and you should see it complet to switch
These codes where quickly made and tbh are not a tidy modifications but work, I will tidy in time.
🙁Version 0.2.2 is the newest version of this library. The Arduino IDE Library Manager incorrectly lists 0.4.0 as the newest version. DO NOT INSTALL VERSION 0.4.0.
The Benewake TFMini-Plus is a unique product, and it is not an enhanced version of the Benewake TFMini. It has its own command and data structures. This library is not compatible with the TFMini product.
Since hardware version 1.3.5 and firmware version 1.9.0, the TFMini-Plus can be configured to use the I2C (two-wire) protocol for its communication interface. The command to configure the device for I2C communication must be sent using the UART interface. Therefore, configuration should be made prior to the device's service installation either by using the TFMini-Plus library or by using a serial GUI test application available from the manufacturer. Thereafter, this libarary can be used for all further communication with the device.
This library calls the Arduino standard I2C/Two-Wire Library.
The getData( dist, flux, temp, addr) function passes back three, unsigned, 16-bit data values and sends an optional, unsigned, 8-bit address. If the default device address is used, the optional addr value may be omitted. Otherwise, a correct addr value always must 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, unsigned integer variables:
● dist Distance to target in centimeters. Range: 10 - 1200
● flux Strength or quality of returned signal in arbitrary units. Range: 0 - 65535
● temp Temperature of the device in code. Range: -25°C to 125°C
For further convenience and simplicity, a getData( dist) function is included. This function passes back data only to the dist variable and requires use of the default I2C address.
The sendCommand( cmnd, param, addr) function sends an unsigned, 32-bit command, an unsigned, 32-bit parameter and an optional, unsigned, 8-bit I2C address to the device. A proper command (cmnd) must be chosen from the library's list of defined commands. A parameter (param) can be entered directly (0x10, 250, etc.), or chosen from the Library's list of defined parameters. If the default device address is used, the optional addr value may be omitted. 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.
An erroneous command or parameter can block communication, and there is no external means of resetting the device to factory defaults.
In I2C mode, the TFMini-Plus functions as an I2C slave device. The default address is 16 (0x10 Hex), but is user-programable by sending the SET_I2C_ADDRESS command and a parameter in the range of 1 to 127. The new address will take effect immediately and permanently without sending a SAVE_SETTINGS command.
If the device I2C address is any value other than the default of 16, the new, non-default address must be included with every subsequent library function as the optional addr byte.
The RESTORE_FACTORY_SETTINGS command will reset the device to the default address of 0x10. The SYSTEM_RESET command appears to have no effect on the I2C address.
Benewake is not forthcoming about the internals of the device, however they did share this:
Some commands that modify internal parameters are processed within 1ms. Some commands (that) require the MCU to communicate with other chips may take several ms. And some commands, such as saving configuration and restoring the factory (default settings) need to erase the FLASH of the MCU, which may take several hundred ms.
Also, according to Benewake:
The measuring frequency (frame-rate) of the module should be 2.5 times larger than the I2C reading frquency.
The I2C reading frequency should not exceed 100Hz.
Benewake says the data frame-rate is limited to 1KHz, which would suggest a 400Hz data sampling limit in I2C mode. But Benewake also says data sampling should not exceed 100Hz. They don't say why; but you might keep those supposed limitations in mind while you are using the I2C interface.
Frame-rate changes should be followed by a SAVE_SETTINGS command or may be lost when power is removed. There is no way to determine what the data frame-rate is actually set to.
The RESTORE_FACTORY_SETTINGS command will not restore the device to the default, UART communication interface mode. The only way to return the device to serial mode is to send the SET_SERIAL_MODE command.
Also included in the repository are:
● An Arduino sketch "TFMPI2C_example.ino" in the Example folder.
● An Arduino sketch "TFMPI2C_changeI2C.ino" in the Example folder.
● Recent copies of manufacturer's Datasheet and Product Manual in Documents.
● General information regarding Time of Flight distance sensing and the Texas Instruments OPT3101 module in Documents in the TI OPT3101 sub-folder.
All of the code for this Library is richly commented to assist with understanding and in problem solving.