The ultra-low power sensor acquisition star network system is mainly used for sensor data acquisition and control of the Internet of Things. The whole network system is composed of gateway IOT-G010 and node IOT-N010/ IOT-THS010, which uses a wireless star network combined with Mesh networking. A good coordination mechanism and precise scheduling algorithm are used internally between the node and the gateway to avoid collisions between data packets in the air. The communication protocol between the node and the gateway has been implemented by the system, and customers can build a reliable acquisition and control network as long as they follow a simple configuration.
■ Node ultra-low power consumption
■ Star network combined with Mesh networking
■ Multi-point data collection (Up to 255 Node for a single gateway)
■ Serial data input and output
■ Multi-level data collision avoidance mechanism
■ Serial port firmware upgrade
■ OTA firmware upgrade
■ Dynamically modify the upload interval
■ Wake up in the air and wake up the lower computer
■ OTA parameter modification
■ Industrial grade (-40～+85 ℃)
■ Multiple anti-crash mechanisms
■ Wireless data encryption
■ Reserve multiple interfaces such as SPI, I2C, GPIO, etc.,Strong scalability
■ Quickly customize various functions
■ Accurate calculation of battery life
■ RSSI signal strength indicator
■ Automatic retransmission mechanism
■ Lost Link indicator
■ Various sensor signal acquisition and control
■ Smart home
■ Security, access control
■ Remote control
■ Industrial control
■ Multi-channel switch / door magnetic signal collection summary
■ Smart manhole cover
■ Remote meter reading
■ Sensor signal acquisition and control
1. Gateway working mode
Through different commands, the gateway can enter the setting module, and set the parameters of itself and the corresponding node in the setting mode. After the command is sent, it will automatically enter the normal working module.
2. Data output method selection
The gateway has two data output methods: USB output and Ethernet output. Switch by pressing the key.
The red light flashes twice, indicating that the serial port is switched to the Ethernet module and output through the RJ45 interface.
The blue light flashes twice, indicating that the serial port is switched to the USB-to-serial chip and output through the USB interface.
3. Gateway parameter description and modification
Gateway ID (GW_ID): used for network identification, nodes with the same gateway ID belong to the same network.
Wireless channel (rf_channel): used to set the wireless frequency, which can reduce co-frequency interference when multiple networks.
Wireless rate (data_rate): used to set the wireless transmission rate.
Transmit power (tx_power): used to modify the transmit power of the module.
Polling interval (poll_interval): used to set the data upload interval of all nodes in the network.
Total number of nodes (nodes_total): The network needs to change parameters to dynamically adjust the upload interval between nodes.
Note: The range of gateway parameters and the command reference file "Gateway parameter settings and communication protocol v1.0.txt"
4. Modify node upload interval at runtime
The upload interval of all nodes in the same network must be the same. Therefore, when the gateway parameter "poll_interval" is modified, it is equivalent to changing the upload interval of all nodes. The gateway will automatically modify this parameter when the next upload time of all nodes arrives.
The polling interval (poll_interval) is in seconds and the maximum range is 65535. The minimum polling interval is related to the number of nodes in the network. In order to prevent data collision between nodes, the transmission interval between two nodes should be at least 1s. Therefore, the polling interval of a node should be the number of nodes N multiplied by 1s. For example, if the number of nodes in the network is 5, the minimum polling interval is 5 seconds, and when the number of nodes is 64, the minimum polling interval is 64 seconds.
5. About packet length
Due to the physical limitation of the wireless chip, the maximum length of a single packet of a data packet is 120 bytes. If the length of the client data is greater than 120 bytes, it needs to be sent in packets by the client.
6. About the choice of rate
The wireless rate of the system supports 1200bps~500Kbps. The choice of rate requires a trade-off between power consumption and distance according to the actual application. Choosing a low rate can achieve a longer distance, but it will increase the transmission time, which is equivalent to increased power consumption.
7. Node offline indication
The gateway can monitor the working status of the node in real time. When the gateway fails to receive node information for 3 consecutive transmission cycles, it will send a corresponding alarm message to the server.
8. Serial port firmware upgrade
The gateway can upgrade the firmware through the serial port. For the specific upgrade method, refer to the file "Gateway Serial Port Firmware Upgrade Tutorial".
9. Indicator light description
Ø Wireless sending and receiving instructions
After the gateway successfully transmits a packet of data, the red light flashes once.
After the gateway receives a packet of data, the blue light flashes once.
Ø Serial switch indication
Short press the button, the red light double flashes, indicating that the serial port is switched to the Ethernet module.
Short press the button, the blue light double flashes, indicating that the serial port is switched to USB to serial port IC.
Ø Node firmware upgrade mode indication
In normal working mode, press and hold the button for 3 seconds, the blue light will be on, indicating that it has entered the node firmware upgrade mode.
In the node firmware upgrade mode, long press the button for 3s, the blue light goes out, which means to exit the node firmware upgrade mode.