1. Preface
Bluetooth wireless technology is one of the most widely used short-range wireless standards in the world. As a short-range wireless connection technology, it can realize convenient, flexible, secure, low-cost, and low-power data and voice communications between devices. It inherits the inherent advantages of Bluetooth technology in wireless connectivity, while adding the features of high-speed Bluetooth and BLE.
2. Brief introduction for CC2640
The CC2640 device is a wireless MCU targeting Bluetooth applications. The device is a member of the CC26xx family of cost-effective, ultralow power, 2.4-GHz RF devices. Very low active RF and MCU current and low-power mode current consumption provide excellent battery lifetime and allow for operation on small coin cell batteries and in energy-harvesting applications. The CC2640 device contains a 32-bit ARM Cortex-M3 processor that runs at 48 MHz as the main processor and a rich peripheral feature set that includes a unique ultralow power sensor controller. This sensor controller is ideal for interfacing external sensors and for collecting analog and digital data autonomously while the rest of the system is in sleep mode. Thus, the CC2640 device is ideal for a wide range of applications where long battery lifetime, small form factor, and ease of use is important.
The Bluetooth Low Energy controller is embedded into ROM and runs partly on an ARM Cortex-M0 processor. This architecture improves overall system performance and power consumption and frees up flash memory for the application.
Figure 1 Star network topology
Figure 2 Broadcast group topology
For star network, any slaves are connected to the master, the access control of the master to the slaves is convenient and flexible. The protocol is also relatively simple and convenient for monitoring and management. In the fault detection, the master can be used to check the slaves one by one to facilitate troubleshooting. A single connection only affects one device and does not affect all devices.
3. E74-2G4M02S
The product E74-2G4M02S of Ebyte supports both star network and broadcast group. It supports the principle of multi-subordination, multi-subordination, and master-slave integration.
Figure 4 One master for multi-salvesThe master device 1 can simultaneously connect the slave device 2, the slave device 3, and the slave device.
The data sent by the device 1 can be simultaneously received by the other three devices, and the data transmitted by the device 2, the device 3, and the device 4 can be received by the device 1.
Figure 5 Multi master for one salve
The slave device 1 can be simultaneously connected to the master device 2, the master device 3, and the master device.
Figure 6 master-slave integration
On the left side of figure 6, that is, when device 1 is a master device and is simultaneously connected to slave device 2 and slave device 3, it is still in a broadcast mode, and can be scanned by master device 4 and establish a connection. The data sent by the device 1 can be simultaneously received by the other three devices, and the data transmitted by the device 2, the device 3, and the device 4 can be received by the device 1. On the right side of figure 6, that is, after device 1 is connected as master device to slave device 2, it is still in broadcast mode, and can be scanned by master device 3 and master device 4, and a connection is established. The data sent by the device 1 can be simultaneously received by the other three devices, and the data transmitted by the device 2, the device 3, and the device 4 can be received by the device 1.
4.Conclusion
The broadcast group topology is mainly applied to the beacon scenario. The simplest understanding is that a small information base station can be used in indoor navigation, mobile payment, in-store shopping guide, flow analysis, item tracking, and all other activities related to indoor mobility. With the development of the times, modern people are increasingly relying on mobile devices, and more and more activities are being performed indoors. Outdoor navigation such as GPS has some dead angles in the interior and is susceptible to interference from buildings. And accuracy and power consumption cannot meet the needs of indoor positioning. Therefore, Beacon which based on Bluetooth has emerged as an ideal solution for indoor applications. Beacon technology is to capture and push information to mobile devices in the communication coverage through Bluetooth Smart.
In short, TI CC2640 can be used in many applications. Building automation, industrial automation, health and medical care, sports and fitness equipment, wearable devices and retail businesses are all applicable.
