Product description: Digital distance sensor 300 cm PWM - Pololu 4079
Module equipped withdistancesensor based onLidartechnology. Module equipped with distance sensor based onLidartechnology. The sensor detects objectsup to 130 cmand is poweredfrom 3 V to 5.5 V. The board is equipped with one PWM digital output whose signal is similar to the servo control signal. The digital pin of the microcontroller can be used to measure the duration of each high pulse, which encodes the measured distance. Short range Lidar technology is used toaccurately measurethe time it takes for the emitted pulses of eye-safe infrared light to reach the nearest object and be reflected back. During sensor operation, continuous distance measurements are taken and ranges are coded as high pulse widths, which can then be synchronized by a microcontroller using a single digital input. A maximum range of 300 cm is only achievable for high reflectance targets in good environmental conditions. Targets with lower reflectivity or poor environmental conditions reduce the maximum range.
Infrared light emitted by the sensor, recorded with a camera without IR filter.
Digital distance sensor 300 cm.Using the distance sensor
The sensor is equipped with 3 leads:VIN, GND and OUT,in the form of holes with a raster of 2.54 mm, with the possibility of solderinggoldpin connectors(not included). VIN pin should be provided with voltagefrom 3V to 5.5V.GND is a ground pin (0 V). Digital pulses are sent to the OUT pin. The low level of the pulses is 0 V and the high level is the voltage value from VIN. When an object is detected,a redLEDalso lights up, which glows brighter when the object is closer to the sensor.There is also an ENABLE pin on the board that can be set low to put it into a low power state, which consumes about 0.4 mA of current. The ENABLE pin is pulled up to VIN by default.
There is a protective film on the sensor that must be removed before working with the module.
Jumper settings on the sensor module
Four surface mount configuration jumpers (4321) are included on the board to define its operating modes. Different versions of Pololu sensors have jumpers set appropriately in the form of 0 Ω resistors. The resistors can be soldered out or bridges can be added to convert one version of the sensor into another. This sensor can be converted to any other version of irs17a according to the table below.
Pin and jumper layout of the distance sensor module.
| Product | Description | Range max. | Hysteresis | Distribution | Minimum update frequency | Jumper settings (4321) |
|---|---|---|---|---|---|---|
| #4066 | Digital output, 25 cm | 25 cm | 50 mm | - | 100 Hz | 0000 |
| #4067 | Digital output, 50 cm | 50 cm | 50 mm | - | 100 Hz | 0001 |
| Digital output, 75 cm | 75 cm | 50 mm | - | 100 Hz | 0010 | |
| #4069 | Digital output, 100 cm | 100 cm | 50 mm | - | 100 Hz | 0011 |
| Digital output, any detection | ~130 cm | - | - | 100 Hz | 0010 | |
| #4071 | PWM output, max. 130 cm | ~130 cm | - | 1 mm (- 0.5 µs) | 100 Hz (max. 110 Hz) | 0101 |
| Digital output, 125 cm | 125 cm | 50 mm | - | 30 Hz | 1000 | |
| Digital output, 150 cm | 150 cm | 50 mm | - | 30 Hz | 1001 | |
| Digital output, 175 cm | 175 cm | 50 mm | - | 30 Hz | 1010 | |
| #4077 | Digital output, 200 cm | 200 cm | 50 mm | - | 30 Hz | 1011 |
| Digital output, any detection | ~300 cm | - | - | 30 Hz | 1100 | |
| #4079 | PWM output, max. 300 cm | ~300 cm | - | 2 mm (= 0.5 µs) | 30 Hz (max. 33 Hz) | 1101 |
Comparison of Pololu and Sharp sensors.Comparison with Sharp sensor
The Pololu sensor modules have the sameshape and pin-outsasthe Sharp modules. They are available with the same and larger detection ranges, which means that they can be usedinterchangeably. The sensors in the newer Pololu devices aremuch thinnerthan the Sharp modules, so the zero point is about 7mm closer to the board, and the beam angle is wider in the newer devices.
Pololu distance sensor specifications
- Supply voltage: 3 V to 5.5 V
- Current consumption: 30 mA (typical) when switched on, 0.4 mA when switched off
- Maximum range: 300 cm
- Minimum range: up to 1 mm
- Minimum update rate: 30 Hz to 33 Hz (33 ms to 30 ms period)
- Field of View (FOV): typically 15°, may vary depending on object reflection and environmental conditions
- Output Type: PWM
- Dimensions: 21.6 x 8.9 x 3.5 mm
- Weight: 0.4 g
Output signal diagram.
