The previous Sharp GP2Y1010 dust sensor was already a successful optoelectronic product due to its small factor, simplicity and low cost. The 1051 update comes with some important improvements to make this an even better product, while using the exact same enclosure shape and size.

The connector

It’s the same 6 pin connector, but the pins are reassigned due to the new functionality:

This new model makes using the sensor much easier. To access the readings only 3 wires are needed, two for power and one for UART serial communication (GND, VCC and TX). The previous electrolytic capacitor needed for the pulsing IR led is now built in. There is also a microcontroller to handle the detection algorithm and the serial interface.

Reading the output

To check the output I connected the sensor to my computer, with an USB to UART adapter based on a CH340 chip. The sensor’s baudrate is 2400bps.

This concluded all required setup and we immediately got the dust measurements over the serial connection:

According to the datasheet, the sensor outputs sequences of 7 bytes, starting with 0xAA and ending in 0xFF. I saved the data to a local file, so my code uses that via fread, but the calculations are the same:

uint8_t buf[7];
fread(buf, 1, 7, f);
if (buf[6] == 0xFF && (buf[5] = (buf[4] + buf[3] + buf[2] + buf[1]))) {
	float vo = (buf[1] * 256.0 + buf[2]) / 1024.0 * 5.00;
	printf("vo:%2.2f pm2.5:%3.2f ug/m^3\n", vo, vo * 700.0);
}

We use the first two bytes to compute the voltage level returned by the photocell. Notice that the 5.00 constant should match your Vcc level. The dust quantity expressed in micrograms per cubic meter of air, is obtained multiplying the vo with 700. Byte number 5 is a checksum, merely the sum of the first 4 bytes, and byte 6 is always 0xFF. Use this to make sure the data received from the sensor is correct.
Here’s an output example:
vo:0.02 pm2.5:13.67 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
vo:0.00 pm2.5:3.42 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
vo:0.01 pm2.5:10.25 ug/m^3
vo:0.01 pm2.5:10.25 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
vo:0.01 pm2.5:10.25 ug/m^3
vo:0.01 pm2.5:10.25 ug/m^3
vo:0.00 pm2.5:3.42 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
vo:2.06 pm2.5:1442.38 ug/m^3
vo:2.06 pm2.5:1442.38 ug/m^3
vo:2.06 pm2.5:1442.38 ug/m^3
vo:3.39 pm2.5:2375.49 ug/m^3
vo:3.39 pm2.5:2375.49 ug/m^3
vo:3.39 pm2.5:2375.49 ug/m^3
vo:3.39 pm2.5:2375.49 ug/m^3
vo:0.17 pm2.5:116.21 ug/m^3
vo:0.17 pm2.5:116.21 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
vo:0.01 pm2.5:10.25 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
vo:0.00 pm2.5:3.42 ug/m^3
vo:0.01 pm2.5:6.84 ug/m^3
The high figures (2375.49 ug/m^3) were produced by inserting an opaque object via the air channel. The low values were recorded in normal conditions.

Datasheet details

VCC: 4.8 – 5.2V
Standby supply current: 20mA
Detectable dust concentration: 30 – 1500ug/m3
Operating Temperature Range: -10 to +65°C
Output Method: UART
Minimum particle diameter: 0.3 um
Dimensions: 48(W) × 32(H) × 7.6(D) [mm]
Humidity Range: 95%rh or less