Stm32h750vbt6 drives programmable gain amplifier module pga113 -- Hal Library Based on cubemx

Preface

Gao Qing has chased xiaoyunkong , Don't dream with pear flowers .

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lately , Because of the need to prepare for the video game , A programmable gain amplifier module is needed （PGA113）, That is, the protagonist of this blog ： Brother Po （ Homophonic address ）, We need to get through this big brother , Today, I finally finished the driver code . Speaking of tune PGA113 The process of this big brother , It's really a little emotional .

Originally, this module was a gain amplification module that another team needed to do the first game preparation project , They bought chips （ Why buy chips ？ Because the module is too expensive , Can't afford to buy . Here is the purchase link of Taobao module ：https://item.taobao.com/item.htm?id=673514214019, I recommend buying a module first , After you understand it, buy a chip and make it yourself , Don't be like us , Directly bought sixorseven chips , As a result, almost no one can adjust it , The boss can do it according to his own ideas ）, And then weld the circuit by yourself , Make modules , As a result, the students in charge of software in their team couldn't be transferred , Then we started “ Politely refuse ” link , Final adjustment PGA113 The task falls on me .

Fortunately, it was finally adjusted , Because there are not many materials that can be found on the Internet , Just watch it slowly according to a chip manual , It's still in English , A hundred words of roast are omitted here , I don't say much nonsense , Let's share .

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One 、 Introduce

• Introduction to chip manual ：pga113 Chip manual .pdf

brief introduction

PGA yes Pmgrammable Gain Amplifier The English name of , Chinese meaning Programmable gain amplifier .PGA It is a very versatile amplifier , Its magnification can be controlled by program according to needs . Use this amplifier , The magnification can be adjusted by program , send A/D The full-scale signal of the converter is homogenized , Therefore, the measurement accuracy is greatly improved .

Applications ：

• Remote electrometer reading
• Automatic gain control
• Portable data acquisition

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Manual catalog ：

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SPI Sequence diagram

Gain control range selection ：

The most important part ：SPI command

• All we need to do here is SPI Configure to ：Transmit Only Master Mode is enough , We don't need to PGA113 Data transmission to single chip microcomputer ;
• Remember to write instructions Hexadecimal Express ：0x2a00（0x0010 1010 0000 0000）,
  0010 1010： Express Write （write） Pattern ;
  first 0000： Indicates gain magnification ;
  the second 0000： Indicates the number of channels selected ,（ The passage used here 0, The module we designed does not use channels 1, Because the first version uses channels 0, Useless channel 1, The second version is changed , The fact proved that ： Use channel 0 It's still more effective , There is an initial effect that will double the magnification （Bug））

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Let's introduce our protagonist （PGA113）：

• Wiring diagram ：（ So here I'm going to use theta SPI1, Software selection ：CS, use DAC Output 1.5 V The reference voltage of ）

STM32H750VBT6 Single chip microcomputer	PGA113 modular
PA4（DAC1_OUT ）	VREF
GND	GND
PA5（SPI1_SCK）	SCLK
PA7（SPI1_MOSI）	DIO
PC4(SPI1_CS)	CS

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Two 、 New project

1、 Conduct CubeMX To configure

• Turn on the clock ：
  

• Configure clock tree ：
  

• Turn on DAC：
  

• SPI To configure ：
  

• The generated code ：

• The above is done CubeMX The process of generating code .

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3、 ... and 、 Code writing

• stay main.c Add the following code to the file ：

/* USER CODE BEGIN PTD */
// Define the gain array 
uint16_t gainBuffer[8]={
     0x2a00,0x2a10,0x2a20,0x2a30,
						 0x2a40,0x2a50,0x2a60,0x2a70 };
// Corresponding to system amplification :
// Corresponding array subscript ：0, 1, 2, 3, 4, 5, 6, 7
//  Binary gain ：1, 2, 4, 8,16,32, 64,128
//  Gain range ：1, 2, 5,10,20,50,100,200

//CS Chip selection low level is effective enable , CS Chip selection high level is not enabled 
#define SPI_CS_Enable() HAL_GPIO_WritePin(GPIOC,SPI1_CS_Pin,GPIO_PIN_RESET)
#define SPI_CS_Disable() HAL_GPIO_WritePin(GPIOC,SPI1_CS_Pin,GPIO_PIN_SET)

/* USER CODE END PTD */

// Define function control gain magnification 
void SetGain(int gain)
{
    
	uint8_t gtemp=0;
 
	switch(gain)
	{
    
		case 1:
			gtemp=0;
			break;
		case 2:
			gtemp=1;
			break;
		case 5:
			gtemp=2;
			break;
		case 10:
			gtemp=3;
			break;
		case 20:
			gtemp=4;
			break;
		case 50:
			gtemp=5;
			break;
		case 100:
			gtemp=6;
			break;
		case 200:
			gtemp=7;
			break;
	}
	
	SPI_CS_Enable();
	HAL_SPI_Transmit(&hspi1, (uint8_t *)gainBuffer+gtemp*2, 1, 0xffff);
	SPI_CS_Disable();
}

  /* USER CODE BEGIN 2 */
	
	PrintfUart("wang_test\r\n");
	
	// start-up DAC converter 
	HAL_DAC_Start(&hdac1,DAC1_CHANNEL_1);															
	
	// Voltage conversion : utilize DAC Output 1.5V The voltage of , As a reference voltage (VREF)
	HAL_DAC_SetValue(&hdac1, DAC1_CHANNEL_1, DAC_ALIGN_8B_R, 116);	  

	SetGain(50);
	
	PrintfUart("Over\r\n");
	
  /* USER CODE END 2 */

Four 、 experimental result

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End of sharing , In fact, it's not particularly difficult to finish writing , Just pay attention to some details , for example ： Don't write the hexadecimal format of the command incorrectly （8+2=a, No 6）、 And convert hexadecimal to octal , These two parts are what hurt me when I wrote the driver , Remind people of .

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The above is the sharing content of this blog , If it helps you , Please give me a little praise , thank you ！！！