The evaluation has finally come to an end. In order to achieve the goal of uploading indoor temperature, humidity and atmospheric pressure data to the cloud based on the Essence NB-IoT development board EC-01F-Kit, a baseboard based on the GD32F350 microcontroller was made.
Some necessary modules are added according to the device properties. The baseboard resources include:
GD32F350 MCU minimum system (using 16M external crystal oscillator);
Powered by a single lithium battery;
Two DCDC channels, one for NB module power supply and one for baseboard power supply;
One button;
A tri-color LED;
a buzzer;
A temperature, humidity and atmospheric pressure acquisition module;
A NB development board base.
The baseboard does not have a power on/off circuit, but interested friends can add it later. The microcontroller has sufficient resources to expand the design.
The program design is not perfect yet. At present, it is only implemented according to the successful process of the previous article. Data can be uploaded once by pressing a button and transmitted once every 5 minutes. The sending and parsing of AT commands are realized through the sending process status. The sending is carried out through fixed commands. Only AT+ECMTPUB needs to be modified by the measured environmental data. For the received information, there is only successful parsing at present. After parsing, the next AT command operation is carried out. Other states need to be continuously improved. The buzzer and LED can indicate different states according to needs.
Discussion: During the test, it was found that the status of the first attached network needs to be monitored through real-time query, and the command to subscribe to the message also requires a certain amount of time to wait for a response. Everyone is welcome to discuss the method of building a state machine response mechanism for the microcontroller.
Actual picture:
提升卡
变色卡
千斤顶