Precautions for using the BLE module BLE5101

BLE5101 is a BLE module based on BLE 5.1 protocol, coexistence of master and slave roles, small size, low power consumption, and the working signal frequency band is 2.4GHz.

BLE Description

Refers to the payload size of BLE air single packet data. The MTU of the BLE 4.0/4.1 protocol is 27 bytes, which can be expanded to 251 bytes from the MTU of BLE 4.2 and higher. In actual use, the single packet data is MTU-3, that is, the user can send a maximum of 24 bytes using BLE 4.0/4.1 protocol single packet, and BLE 4.2 and higher versions can be expanded to 247 bytes.

It should be noted that in actual applications, the MTU of different devices will be different.

Precautions for BLE module application

1. Judgment conditions for the role of master and slave

When the module actively scans and connects to other Bluetooth devices, the BLE module assumes the role of the master in this connection; when the module is connected by other Bluetooth devices due to broadcasting itself, the BLE module acts as the slave in this connection.

2. Response of distance to data transmission rate

The BLE module uses PCB antenna. Compared with ceramic antennas, BLE wireless signals have stronger transmitting and receiving capabilities with external antennas. Nevertheless, the data transmission speed of the module will still be attenuated due to the increase in distance.

3. BLE Module data transmission speed changes

The data transmission speed of the module will decrease as the distance increases. And because the BLE module sends data in the form of polling connections, when there are multiple connections, the total data sending time will vary due to the distance and the number of connections. In the case of multiple connections, it is recommended to add a certain delay between each packet of data.

4. BLE Module current may be too high in low power consumption mode

When the module is connected, the connection will remain undisconnected in low power consumption mode, so the current of the BLE module may be slightly higher, but it is always less than 100uA.