Things to Note on Hardware Design

Battery

• If a battery is pre-installed, we recommend that you add a battery separator to avoid continuous power consumption by the device during storage or transportation.
• Make sure that the positive and negative electrodes of the battery are in good contact with the device shrapnel. Otherwise, the service life of the device might be shortened.
• If a rechargeable battery is used, the charging current of the battery cannot exceed the upper limit.
• The power consumption of end products must meet the requirements of different protocols. Button batteries must be avoided for Wi-Fi and NB-IoT products.

PCB

• The printed circuit board assembly (PCBA) must match the device structure. Otherwise, the PCB might be deformed under external forces and thus the components become faulty, causing the service life of the device to be decreased.
• In the PCB design, place the power filter capacitor as close as possible to the VDD pin.
• In the PCB design, all PCB antenna projections of the wireless module are hollowed out to ensure antenna performance.

Sensor

• A smart temperature and humidity sensor is sensitive to heat sources. It must be placed at a certain distance from heating elements. If the PCB is placed vertically, try to turn the sensor to the bottom of the PCB.
• The sensor is isolated from other elements on the PCB to prevent excessive measurement deviation caused by heat conduction. Maximize the size of air vents reserved on the structure to ensure excellent ventilation.
• The sensor cannot be placed together with plastic bags, boxes with glue or paint, or other chemical substances during storage, shipment, or packaging. Otherwise, its measurement result will be inaccurate or faulty.
• In terms of the working environment of the sensor, the working temperature range of the sensor chip does not mean the working temperature range of the end product. The latter temperature range also depends on the working temperature range of other components, such as the battery, network module, sensor chip, peripheral components, and structural materials.