BLE is a low-power Bluetooth technology that can effectively reduce the power consumption of Bluetooth devices and increase the operating time of the device. But even the same BLE device will produce different power consumption rates under different usage conditions. So what exactly affects the power consumption of BLE devices?
The BLE host device is generally in one of the standby, scanning and connected states, while the BLE slave device is in one of the standby, broadcast and connected states. When the BLE device is not connected, the device will wake up intermittently to broadcast and scan. In addition, it will enter a sleep state at other times to save power consumption. After understanding this basic knowledge, let’s look at what can affect the power consumption of BLE devices.
1.Broadcasting (scanning) distance of the device
When the device is not connected, the BLE device will continue to broadcast (scan) intermittently. The shorter the distance between each broadcast (scan), the more times the device wakes up per unit time. In this way, Come, naturally increase the power consumption of the equipment. Therefore, reasonably extending the broadcast (scanning) distance of BLE devices can effectively reduce device power consumption.
However, in addition to affecting the low-power performance of the device, the broadcast (scanning) distance can also affect the connection speed of the device. An excessively long broadcast (scanning) distance will significantly reduce the BLE connection speed and affect the use experience. Therefore, users need to make a choice between low power consumption and connection speed and choose an acceptable level.
2. The duration of the device’s broadcast (scan)
That is, in broadcast (scan) mode, the duration of each broadcast (scan) of the device. The principle is similar to the distance mentioned before. The longer the duration of broadcast (scanning), the longer the device wakes up and the shorter the sleep time per unit time, which will increase the power consumption level of the device. Similarly, the longer the duration of the broadcast (scan), the response speed of the device connection can also be effectively improved.
3. Device connection distance
After the device enters the connection mode, the BLE host device will send a connection event to the BLE host device. After the device receives this event, it will immediately reply to the event to inform the host device that the connection link is normal. The sending and replying of this data is the time when the power consumption is the highest after the entire BLE connection. Therefore, if the distance time of the connection can be increased, the average power consumption level per unit time can be effectively reduced, and the power consumption can be effectively reduced.
However, as mentioned before, reducing the power consumption of the device by increasing the connection distance will slow down the communication response speed of the device. Therefore, when adjusting this parameter, you need to consider whether the communication speed is acceptable to the user.
4. Negligence of the slave machine
That is, the number of times the device can be ignored when connected. In each connection, the BLE host device will first send data, and then the slave device will reply. If no reply is received, the host will think that the device status is abnormal. However, after setting the number of slave delay times, the device will be allowed to have a certain number of times without replying to the host. Non-reply behavior within the set number of times will not cause abnormal judgment of the host. In this way, by reducing the number of replies, the overall power consumption of the device is reduced.
The above are several ways to reduce the power consumption of Bluetooth BLE devices. By extending the scanning distance, connection distance, reducing the number of replies, and increasing the sleep time of the device, the purpose of reducing the power consumption of the device can be achieved. However, in actual use, it is also necessary to consider In terms of connection speed and user experience, after all, you can’t have your cake and eat it too. Reasonable parameter settings can save more power consumption within the range that users can bear.Keywords: 4-channel analog acquisition module