[single chip microcomputer project training] multipoint temperature wireless acquisition system based on nRF905

The single-chip project training —— be based on nRF905 The multi-point temperature wireless acquisition system is shared , If there is any deficiency , Please point out .

【 Experimental picture 】

 

【 Experiment video 】

be based on nRF905 Design of multi-point temperature wireless acquisition system based on

Catalog

One 、 The design requirements

Two 、 The project design

3、 ... and 、 Hardware circuit design

Four 、 software design

5、 ... and 、 Other pictures

6、 ... and 、 The data link

7、 ... and 、 About author

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One 、 The design requirements

        System USES NRF905 As a wireless transceiver , The temperature information collected by the four slave computers is sent to the host computer , The host displays the temperature information at four points , And the upper and lower limit alarm values of the temperature can be set by pressing the key , Audible and visual alarm can be given when the limit is exceeded .

 

Two 、 The project design

        With the development of technology , Wireless information transmission is becoming more and more mature , Compared with wired information transmission , The wireless mode is easy to install and maintain .NRF905 The monolithic wireless receiver is Norwegian Nordic The company has launched a single RF transmitter chip , The working voltage is 1.9V~3.6V, Work in 433、868、915MHZ  3 individual ISM channel , adopt SPI Interface and MCU Connect . because 51 Single chip microcomputer doesn't have SPI Interface , It can be simulated by software SPI Communication protocol for communication . The system scheme block diagram is shown in the figure below .

3、 ... and 、 Hardware circuit design

        Slave use DS18B20 The temperature sensor collects the temperature ,DS18B20 Is the U.S. Dallas Semiconductor's digital temperature sensor , Its single bus control mode can save the limited resources of single chip microcomputer to the greatest extent IO Oral resources , Its I/O Port and single chip microcomputer 8 foot P17 Connected to a . The circuit schematic diagram of the slave is shown in the figure below .

        Host use LCD1602 LCD display ,LCD1602 The LCD screen is equipped with commonly used ASCII code , There are two driving modes , This design takes into account the refresh speed of display data , Decide to adopt parallel port drive mode ; The keys are controlled by independent keys ; The audible and visual alarm part adopts buzzer plus LED instructions . The circuit schematic diagram of the host is shown in the figure below .

        All wireless transceivers are Norwegian Nordic company-launched NRF905 Monolithic wireless transceiver .

        reflection ： By comparing the slave 、 Schematic diagram of main engine , It is found that some of the circuits are the same , There are also some differences , If you draw PCB Proofing , Two types of design are required PCB circuit , Considering the cost and actual design needs , The author designed “ Master slave integrated machine ”, That is, slave 、 The host is the same circuit , Only some components do not need to be welded during specific welding .

  The principle diagram of master-slave integrated machine is as follows ：

remarks ：D1~D8 Meaning of indicator light ：

D1:1 The ambient temperature measured by slave No. 1 is lower than the lower temperature limit ;
D2:1 The ambient temperature measured by slave No. 1 is higher than the upper temperature limit ;
D3:2 The ambient temperature measured by slave No. 1 is lower than the lower temperature limit ;
D4:2 The ambient temperature measured by slave No. 1 is higher than the upper temperature limit ;
D5:3 The ambient temperature measured by slave No. 1 is lower than the lower temperature limit ;
D6:3 The ambient temperature measured by slave No. 1 is higher than the upper temperature limit ;
D7:4 The ambient temperature measured by slave No. 1 is lower than the lower temperature limit ;
D8:4 The ambient temperature measured by slave No. 1 is higher than the upper temperature limit ;

Four 、 software design

        The master first assigns different addresses to the slave , Then the address is used to distinguish which data is sent from the machine .4 A slave will send a temperature sensor DS18B20 The measured temperature value passes NRF905 The wireless module transmits data to the host .

        （ One ） Slave sender

        1. The main program ：

void main()
{
    
	system_init();
	while(1)
	{	
		DS18B20_ReadTemperature(&temp);
		display();
		send();     
	}
}

2. Program analysis

        （ Two ） Host receiving end （ The download link is in part 6 of this article ）

        1. The main program

void main(void)
{
	System_Init();
	while(1)
	{
		Receive_Data();
		Display();
		Limit_Set();
		Alarm();
	}
}            

        2. Program analysis

5、 ... and 、 Other pictures

（ One ）PCB -3D View

1. host -PCB-3D    Opposite side

2. Slave -PCB-3D    Opposite side

（ Two ） Physical drawing of the system

1. Overall renderings

2.1 No. 1 slave drawing

3.2 No. 1 slave drawing

4.3 No. 1 slave drawing

5.4 No. 1 slave drawing

6. Main engine diagram  

7.PCB Blank plate drawing - positive

 7.PCB Blank plate drawing - Back

 9.PCB- Main engine parts

10.PCB- Slave parts

11.PCB- Master slave parts

  6、 ... and 、 The data link

（1） Work demonstration video chain ：

link 1： Bili, Bili be based on nRF905 Design of multi-point temperature wireless acquisition system based on _ Bili, Bili _bilibili System USES NRF905 As a wireless transceiver , The temperature information collected by the four slave computers is sent to the host computer , The host displays the temperature information at four points , And the upper and lower limit alarm values of the temperature can be set by pressing the key , Audible and visual alarm can be given when the limit is exceeded .https://www.bilibili.com/video/BV1Dm4y1Z7Fv?spm_id_from=333.999.0.0

  link 2： Youku Video https://v.youku.com/v_show/id_XNTgzNjM0MDA0NA==.htmlhttps://v.youku.com/v_show/id_XNTgzNjM0MDA0NA==.html

（2） Hardware circuit analysis video ：

link 1： Bili, Bili

【 project training 】 be based on NRF905 Multi point temperature acquisition wireless system · Hardware circuit analysis _ Bili, Bili _bilibili System USES NRF905 As a wireless transceiver , The temperature information collected by the four slave computers is sent to the host computer , The host displays the temperature information at four points , And the upper and lower limit alarm values of the temperature can be set by pressing the key , Audible and visual alarm can be given when the limit is exceeded . Please refer to blog for details ：https://blog.csdn.net/yagnruinihao/article/details/118342915?spm=1001.2014.3001.5501https://www.bilibili.com/video/BV1aT4y1X7HT?share_source=copy_web link 2： Youku Video

https://v.youku.com/v_show/id_XNTg0MTk3ODYxNg==.htmlhttps://v.youku.com/v_show/id_XNTg0MTk3ODYxNg==.html（3） Software program analysis video ：

link 1： Bili, Bili

【 project training 】 be based on NRF905 Multi point temperature acquisition wireless system · Software program analysis _ Bili, Bili _bilibili System USES NRF905 As a wireless transceiver , The temperature information collected by the four slave computers is sent to the host computer , The host displays the temperature information at four points , And the upper and lower limit alarm values of the temperature can be set by pressing the key , Audible and visual alarm can be given when the limit is exceeded . Please refer to blog for details ：https://blog.csdn.net/yagnruinihao/article/details/118342915?spm=1001.2014.3001.5501https://www.bilibili.com/video/BV1X5411o7sW?share_source=copy_web link 2： Youku Video https://v.youku.com/v_show/id_XNTg0MTUxMzk2OA==.htmlhttps://v.youku.com/v_show/id_XNTg0MTUxMzk2OA==.html

（3） Schematic link

Scheme 1 ： host 、 The slave machine is separated

https://download.csdn.net/download/yagnruinihao/80606461https://download.csdn.net/download/yagnruinihao/80606461 Option two ： Master slave integrated machine

https://download.csdn.net/download/yagnruinihao/80606742https://download.csdn.net/download/yagnruinihao/80606742（4） Source program link ：https://download.csdn.net/download/yagnruinihao/80608034https://download.csdn.net/download/yagnruinihao/80608034

7、 ... and 、 About author