Application Guide for Foxconn FSTOF2002C0U Time of Flight Sensor Module - sharpsensoruser/sharp-sensor-demos GitHub Wiki
Application Guide for Foxconn FSTOF2002C0U Time of Flight Sensor Module
Foxconn FSTOF2002C0U Time of Flight Sensor Module Application Guide
Overview
FSTOF2002C0U is the new module version of Sharp's GP2AP02VT00F Time-of-Flight (TOF) sensor which is designed to measure absolute distances from 10cm to 240cm (white card). Sharp GP2AP02VT00F is a very compact I2C sensor commonly used in smartphone applications such as camera auto-focus.
The TOF Module has an on-board MCU, includes a cover lens for the TOF sensor, and provides a digital UART interface. The FSTOF2002C0U module can be used in a variety of distance ranging applications such as:
- Automatic faucets and flush valves
- User detection for ATMs and kiosks
- Robotics obstacle detection
- Copier and vending machines
- Automatic control of lighting
- Factory automation
- Robotic vacuums
The TOF Module is also available in an I2C version instead of UART. The following table summarizes the different versions of the TOF module that are available.
| TOF Module | Distance Range | TOF Sensor | Connector | Interface |
|---|---|---|---|---|
| FSTOF2002C0U | 10cm to 240cm (white card) | Sharp GP2AP02VT00F | 4-pin | UART |
| FSTOF2002C0I | 10cm to 240cm (white card) | Sharp GP2AP02VT00F | 4-pin | I2C |
| FSTOF2002C0D | 10cm to 240cm (white card) | Sharp GP2AP02VT00F | 6-pin | UART / I2C |
| FSTOF2003C0U | 1cm to 30cm (white card) | Sharp GP2AP03VT00F | 4-pin | UART |
| FSTOF2003C0I | 1cm to 30cm (white card) | Sharp GP2AP03VT00F | 4-pin | I2C |
FSTOF2002C0D is a new model with mounting holes and 6-pin connector to support both UART and I2C interface.
TOF Sensor Eye Safety Considerations
The Sharp TOF sensor uses a Class 1 Laser which is safe under conditions of normal use. As per the specification for Sharp GP2AP02VT00F, the laser output from the TOF sensor is Class 1 laser safety under all reasonably foreseeable including single faults in compliance with IEC 60825-1:2014. The laser output will remain within Class 1 limits as long as the Sharp recommended device settings are used and the operating conditions specified in the Sharp GP2AP02VT00F specification are respected. The laser output power must not be increased by any means and no optics should be used with the intention of focusing the laser beam.
TOF Module Specifications
Module Appearance
The TOF Module is comprised of a PCBA board with MCU and a 4-pin connector. On the opposite side of the connector is the actual TOF sensor which is encased behind a rectangular cover and lens.
Module Connector
FSTOF2002C0U uses a 4-pin connector made by JCTC (Shenglan Technology Co. Ltd):
- Module-side connector: JCTC 11002W00-4P-S-HF
- Mating connector housing: JCTC 11002H00-4P-HF
- Mating connector terminal: JCTC 11002TOP-2E
Note that JCTC connectors may be difficult to source in North America. As an alternative, try the JST SH series 1.0mm pitch 4-pin connector which should be compatible with JCTC. JST connectors are easy to find on ebay and you can purchase a set of 10 JST cable assemblies for just a few dollars.
Field of View (FOV)
The FSTOF2002C0U cover lens gives it a standard Field-of-View (FOV) of 25 degrees, which is suitable for a wide range of applications such as user or object detection.
Serial Port Protocol Settings
The following are the serial port settings for communicating with the TOF module through its UART interface.
UART Data Packet Format
Command codes and data bytes are transmitted to (or received from) the TOF module using the following data packet format.
| Field Offset (bytes) | Field Length (bytes) | Field Type | Description |
|---|---|---|---|
| 0 | 2 | uint16_t | Packet header: 0x55 0xAA |
| 2 | 1 | uint8_t | Command Code |
| 3 | 1 | uint8_t | The length of the following parameter |
| 4 | N | Array of uint8_t | Parameter, N = Data Length, N+4 < 32, depending on the TOF Module buf size |
| L | 1 | uint8_t | End flag: 0xFA, Offset computational formula is L = Data Length + 4 |
UART Command Codes
The following table shows the available UART command codes which can be transmitted to the TOF module. For example, to request a distance measurement/reading, send the 0x81 command code. The TOF module will return a distance in units of MM = millimetres using the Data Packet Format described in the previous section.
| Command Code | Description |
|---|---|
| 0x81 | Measure distance in units of mm |
| 0x82 | Crosstalk calibration |
| 0x83 | Offset calibration |
| 0x84 | Reset TOF module |
| 0x85 | Read factory data |
| 0x86 | Read version information |
| 0x8A | Read debug parameter section 1 |
| 0x8B | Read debug parameter section 2 |
| 0x8C | Read debug parameter section 3 |
| 0x91 | Set the threshold of interrupt output |
| 0x92 | Set the ranging mode |
Here are some examples of sending various command codes, and the received data.
| Command Description | Send Data | Receive Data |
|---|---|---|
| Measure a distance of 50cm | 0x55 0xAA 0x81 0x00 0xFA | 0x55 0xAA 0x81 0x03 0x01 0xF4 0x00 0xFA |
| Read version info | 0x55 0xAA 0x86 0x00 0xFA | 0x55 0xAA 0x86 0x03 0x02 0x41 0x05 0xFA |
Using FSTOF2002C0U with Arduino
Arduino Circuit
Connect the TOF module to your Arduino board as shown in the figure below. This example uses Arduino Uno but it should work the same with Arduino Mega 2560. Note that the TOF module requires a power supply voltage between 3.0V and 3.6V. In addition, the TXD and RXD pins of the TOF module operate on 3.3V logic, so it is necessary to use a logic level converter to convert between 3.3V and the 5V that the Arduino digital pins use.
In the circuit, the hardware serial port is used only for printing output distances to the Arduino Serial Monitor. A software serial port is used for the actual communication with the TOF module (Arduino pins 10 and 11) as shown in the demo source code. If you're using Arduino Mega, you can use one of the other hardware serial ports instead such as Serial1 for communicating with the TOF module.
The demo source code shows how to request a distance measurement by sending the 0x81 command code to the TOF module, process the returned data from the module, and then display the distance in millimetre units on the Serial Monitor.
This Arduino code should also work for the Foxconn FSTOF2003C0U (short ranging) TOF module since it has the same UART interface and specification.
Example Serial Monitor Output
If you are switching between different Arduino boards, make sure you go to the Arduino IDE Tools menu and set Board and Port appropriately before compiling or uploading the code. The following screen capture shows example output from the TOF module as displayed on the Arduino Serial Monitor.
Using FSTOF2002C0U with Windows Application
There are two standalone Windows applications you can use to control FSTOF2002C0U / FSTOF2003C0U from a PC. In both cases, you will need a FT232RL serial-to-USB adapter and USB cable to connect the TOF module to your PC.
Windows application #1 - TofDemoShow
This is a vendor-provided Windows application to control FSTOF2002C0U / FSTOF2003C0U.
Windows application #2 - FoxconnTofModuleDemo with C#/.NET source code
This is a C#/.NET Windows Forms application for controlling Foxconn FSTOF2002C0U / FSTOF2003C0U time-of-flight sensor modules.
