Recently we talked about the cheapest Wi-Fi smart switch you can add to your smart home. Today, we are talking about the cheapest ZigBee motion sensor, the Tuya ZigBee 3.0 PIR Motion Sensor priced at ~$8.
This small gadget is developed by Tuya and in this review we will open it to take a peak inside, integrate it into Home Asssitant and put it through some test along with the Aqara motion sensor (~$15) to see how they compare.
- Model: ZM-35H-Q
- Connectivity: ZigBee 3.0
- Detection Angle: 120 degrees
- Detection Range: <5m
- Power: Button Battery CR2450
- Working Temperature: -10°C – 45°C
- Dimensions: 33x27mm
To open this mini PIR motion sensor, we need to remove the battery and push the inside PVC body from the top. The protective cap sits on top of the PIR sensor which fits nicely into the round frame.
Once we remove the cap, the PIR sensor is exposed and we can see it’s a PIR BS612 digital passive infrared motion sensor. This components is made by Senba Sensing Teb. in Shenzen, China. This sensor supports sensitivity adjustments, motion delay adjustments (cooldown) and light sensitivity.
On the back panel, a reset button is placed on side which is reachable from the outside with a small pin. On the sides, the battery pins are sticking out. They are a little flimsy, but considering the battery allegedly lasts 1.5 years, this should not be a problem. ZigBee communication is handled by a low powered Z2 ZHU2123 module developed by Tuya.
The Tuya ZigBee Motion Sensor is easily integrated into Home Assistant. To pair it, you stick a little pin in the small hole on the side of it’s body, which engages a reset button. Hold for 5-6 secs and the PIR sensor goes into pairing mode which is indicated by the LED flashing red.
As of this writing of this article, this PIR motion sensor is officially supported only in ZigBee2MQTT. There is ongoing feature request for the ZHA integration which we expect would bring the gadget in ZHA.
It pairs easily in ZigBee2MQTT and is discovered as model ZM-35H-Q, with ZigBee manufacturer ID being TS0202, _TYZB01_dl7cejts, _TZ3000_mcxw5ehu or _TZ3000_msl6wxk9. Once added, it exposes the following entities:
- Occupancy Binary Sensor
- Battery Low Binary Sensor
- Battery Percentage Sensor
- Tamper Binary Sensor
- Keep Time Select Sensor (cooldown)
- Sensitivity Select Sensor
- Link Quality Sensor LQI Signal Quality
Tuya Vs Aqara
Comparing this little PIR sensor to the Aqara RTCGQ11LM motion sensor, which is the most popular motion sensor on the market, gave use some interesting results.
Size wise, they are both really tiny which allows them to be placed in more concealed locations. The Aqara does come with a mouting bracket, which allows for a more versatile installation. The Tuya comes only with a back sticker, so angle fine tuning may present a problem for your use case.
They are almost identical in diameter, with the Aqara being the taller of the two. When pairing the sensor, the Aqara flashes a little LED on the top front of it’s case, while the Aubess flashes its PIR cover completely.
We mounted the two sensors closely together around shoulder height at 90 degrees and performed several range and sensitivity tests. The findings were interesting to say the least.
By brand awareness, you would automatically assume the Aqara is the far superior device. In our tests it turned out the Tuya Mini PIR Motion Sensor delivered on-par results and considering its available configuration variables in ZigBee2MQTT it is not to be discarded so fast.
Although the Aqara detects motion at above 5 meters (16.4 feet) it offers no way to set sensor sensitivity. This is a configurable parameters on the Tuya Mini PIR Sensor on which you are able to set the sensitivity to low, medium or high. This affects two things: sensitivity to movement and range of the sensor.
Scenario 1: Low sensitivity setting
- Detected Motion: 1-1.5 meters (3.28-3.94 feet)
- Sensitivity: Walk within 1 meter (3.28feet)
Scenario 2: Medium sensitivity setting
- Detected Motion: 2-2.5 meters (6.56-7.54 feet)
- Sensitivity: Move within 2 meters (6.56 feet)
Scenario 3: High sensitivity setting
- Detected Motion: 4-4.5 meters (13.12-14.76 feet)
- Sensitivity: Wave hand within 4 meters (13.12 feet)
State Keep Time (Cooldown)
Perhaps the most important parameter which can be set on the Tuya PIR Sensor and is absent on the Aqara is the cooldown time of the sensor. It offers 4 keep time settings:
- Default: 15sec
- Low: 30sec
- Medium: 60sec
- High: 120sec
The Aqara default state keep time is a whopping 120sec! To reduce this parameter to 5 sec you need to solder two points on the PCB. See more HERE.
The Aqara edges out the Tuya sensor in angle motion detection. It is advertised as covering a 170° angle while the Tuya covers only 120°. In our tests the Aqara detected motion within it’s advertised parameters, while the Tuya got triggered between 100-110°.
The Tuya PIR Motion Sensor is a fit for it’s purpose device. It pairs easily with ZigBee2MQTT and works flawlessly with Home Assistant. Because it is a battery powered end device, its performance largely depends on the quality of your ZigBee mesh network.
In our tests, it never failed to detect motion when the sensitivity was set to High. Just waving your hand from 4-4.5 meters would trigger the sensor and update the entity in HA. The lack of a mounting bracket, such as the one on the Aqara, makes it a little trickier to mount in some places and limits its potential. Whether this a breaking point, its up to you to decide. Considering the price tag, we would definitely recommend this small gadget. If you want to test it yourself, consider using one of our affiliate links bellow.
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