PIR (Motion sensor)

In this page, you will learn how the PIR sensor works and what available settings you can change.

Since the device is primarily solar-powered, the PIR sensor cannot be always ON, as the device will need a lot of light on average.

Therefore, we have implemented a duty-cycle on the PIR - turning it ON for certain period of time and turning it OFF for some period. This means that the device may not always report accurate movement detection.

If you need to have the PIR constantly enabled and detecting movement, you have to insert 2 or 4 AA batteries and reconfigure the settings of the PIR sensor.

If you want to do this, we recommend sending the following downlink to the device:

Option 1 - blind period 1 minute: 3C014A00004C003C3D4B4D Option 2 - blind period 10 minutes 3C014A00004C02583D4B4D Read more about blind period below.

PIR Status

This commands allow you to set/get the PIR status - whether it's enabled or disabled at all. By default, the PIR is disabled.

SET

Byte index	Hex value – Meaning
0	3C – The command code.
1	00 – Disable the PIR sensor; Default state. 01 – Enable the PIR sensor.

Example downlink: 0x3C01 – Turn on the PIR sensor.

GET

Byte index	Sent request	Received response
0	3D – Command code	3D – Command code
1		00 - The PIR sensor is disabled. 01 - The PIR sensor is enabled

Example downlink sent by the server: 0x3D;

Example command response: 0x3D01 – The PIR sensor is on.

PIR Blind period

After detecting a movement in the room, the PIR sensor is disabled for the specified blind period to avoid too many uplinks, improving the energy usage - saving battery or requiring less light to harvest.

Example with Blind period of 1 minute:

• The moment the sensor detects movement, it sends an uplink.

• Then the PIR is powered down for 1 minute to save energy.

• After 1 minute, the PIR is powered up again and the device will send a new uplink immediately after the PIR detects movement.

The shorter the Blind period, the more time-accurate detection of movement and more uplinks, but more energy is used.

SET

Byte index	Hex value – Meaning
0	4C – The command code.
1	XX – PIR blind period data, bits 15:8;
2	XX – PIR blind period data, bits 7:0. Minimum value = 15sec. Default value 0x0258 = 600s = 10min.

GET

Byte index	Sent request	Received response
0	4D – Command code	4D – Command code
1		XX - PIR sensor blind period - bits 15:8
2		XX - PIR sensor blind period - bits 7:0

PIR Check period

This value instructs the sensor what's the period between measurements. Outside this time, the sensor is not powered.

When the value is 0, the PIR is constantly powered and checking for movements.

SET

Byte index	Hex value – Meaning
0	4A – The command code.
1	XX – PIR check period data, bits 15:8;
2	XX – PIR check period data, bits 7:0. Minimum value = 0sec. Default value = 0x36 = 54sec.

Example downlink: 0x4A0006 – Set the PIR check period to 6sec.

GET

Byte index	Sent request	Received response
0	4B – Command code	4B – Command code
1		XX - PIR sensor check period - bits 15:8
2		XX - PIR sensor Check period - bits 7:0

Example downlink sent by the server: 0x4B;

Example command response: 0x4B0006 – Measurement period of the PIR sensor = 6 sec.

PIR Measurement period

The PIR Measurement period is a value that instructs the sensor how long after turning on + initialisation period it should be checking for movements before going back to sleep.

SET

Byte index	Hex value – Meaning
0	48 – The command code.
1	XX – PIR measurement time period. Minimum value = 3sec. Default value = 3sec.

Example command: 0x4804 – Set the measurement period of the PIR sensor = 4sec

GET

Byte index	Sent request	Received response
0	49 – Command code	49 – Command code
1		XX - PIR sensor measurement period [sec]

Example downlink sent by the server: 0x49;

Example command response: 0x4904 – Measurement period of the PIR sensor = 4 sec

PIR Sensitivity

The PIR sensitivity can be set from 12 to 255. The minimum value we advise setting is 12 or 0x0C - the sensor will be super sensitive to movements.

The higher the value, the less sensitive the PIR sensor is to movement.

Minimum = 12 - very sensitive

Maximum = 255 - less sensitive

SET

Byte index	Hex value – Meaning
0	3Е – The command code.
1	XX - PIR sensor sensitivity. 0x14 is the dafault value.

Example downlink: 0x3E1E – Set PIR sensor sensitivity 0x1E = 30.

GET

Byte index	Sent request	Received response
0	3F – Command code	3F – Command code
1		XX - The sensitivity of the PIR sensor

Example downlink sent by the server: 0x3F;

Example command response: 0x3F1E – The sensitivity of the PIR sensor = 0x1E => converted to decimal = 30.

Initialisation period

Every time the sensor turns on, it needs a little time to get used to the light conditions in the room.

We do not advise changing the default initialisation period!

SET

Byte index	Hex value – Meaning
0	46 – The command code.
1	XX – PIR sensor init period in seconds. Minimum value = 3sec. Default value = 3sec.

Example downlink: 0x4603 – Set the initialisation period of the PIR sensor = 3sec.

GET

Byte index	Sent request	Received response
0	47 – Command code	47 – Command code
1		03 - PIR initialisation period.

Example downlink sent by the server: 0x47;

Example command response: 0x4703 – Initialisation period of the PIR sensor = 3 sec.