Product description: TOF laser distance sensor - 15 m - UART / I2C - Waveshare 21221
A laser distance sensor that uses ToF (Time of Flight) measurement technology. The measuring range of the sensor is from 0.01 m to 15 m with an accuracy of ± 1% to ± 2%. The measurement resolution is 1 mm. The sensor communicates with the microcontroller via the UART or I2C interface. It is powered with a voltage in the range from 3.7 V to 5.2 V. The angle of view (FoV) of the sensor can be adjusted in the range from 15° to 27°. The user has two communication interfaces to choose from: UART and I2C. These types of sensors are used in robots and drones.
TOF laser distance sensor - 15 m - UART / I2C - Waveshare 21221.
How ToF works.What is TOF?
ToF (Time-of-Flight) is one of the absolute distance measurement technologies. The sensor emits near-infrared light that is reflected when it encounters an object. The sensor calculates the distance to the encountered object, through the time difference or the phase difference for light emission and reflection, to obtain depth information. Compared with the binocular plan and the 3D structured lighting plan, the advantages of ToF are large measuring range, multiple application scenarios and high precision. This type of sensors is used for human distance detection, robot obstacle avoidance, camera auto focus, etc. The near-infrared light from sunlight in the outdoor environment affects the distance measurement.
Leads of the laser distance sensor
The ToF distance sensor is supplied with a voltage of 3.7 V to 5.2 V and communicates with the microcontroller via the UART or I2C interface using a 4-pin connector.
- TX/SCL - serial interface transmission line / I2C bus clock line
- RX/SDA - serial interface receiving line / I2C bus data line
- GND - system ground
- VCC - system power line
The product is compatible with Arduino and Raspberry Pi
The manufacturer has prepared a user guide with sample program codes for Arduino and Raspberry Pi users.
An example of connecting the sensor with Arduino. 
Kit contents.
Distance Sensor Specifications
- Measuring range: 0.10 m to 15 m
- Typical Measurement Accuracy:
- from 0.10 m to 2 m: ± 2 cm
- from 2 m to 15 m: ± 2%
- Resolution: 1mm
- Power: 3.7V to 5.2V
- Communication:
- UART (3.3V TTL signal)
- I2C (cascading possible, slave address is 0x08 + module ID)
- Viewing angle (FoV): 1° to 2°
- Transmission speed:
- UART: from 115200 bps to 3000000 bps (default 921600 bps)
- I2C: up to 400kbps
- Cascading:
- I2C: up to 8 sensors can be connected
- Resistance to ambient light: about 100 k lux, can be used indoors and outdoors
- Power consumption: 610mW (active UART output, 5V power supply, 122mA current)
- Operating temperature: -10°C to 60°C
- Dimensions: 22.7 x 28 x 13.6mm
- Weight: 7.7g
Kit contents
- TOF laser distance sensor - 15 m - UART / I2C - Waveshare 21221
- Cable with two plugs 4-pin GH1.25
- 4-pin GH1.25 cable - female wires
