Complete source code download: https://github.com/simonliu009/STM32CubeMX-hardware-I2C-AT24C02
There is a saying that has been circulating on the Internet for a long time, that is, the I2C of STM has bugs and is not easy to use. Indeed, many people have encountered various problems in practical applications, so most of them are using software to simulate IIC.
With STM32CubeMX, we can try to use hardware I2C. There can be no mistake in the official optimization, right? (In fact, there is still a small bug, but it can be corrected). The goal of this article is to use the hardware I2C of STM32CubeMX to perform complete read and write operations on the AT24C02 EEPROM on the Kylin base.
Software version:
STM32CubeMX V4.25.0
System Workbench V2.4
Firmware library version:
STM32Cube FW_F1 V1.6.1
STM32Cube FW_F1 V1.6.1
Hardware: OneNet Unicorn V2.3
Create a new project in STM32CubeMX and select the correct MCU model (or save the old project as well).
First set RCC and SYS, as shown below
Then set the clock according to the actual situation of the board (the external crystal oscillator of Kirin is 12M, and the highest frequency of STM32F103x is 72M), as shown below
To set I2C2, the AT24C02 of Unicorn V2.3 is connected to I2C2, the setting of I2C does not need to be changed, just use the default value.
Open the serial port USART1, and the serial port settings do not need to be modified. The default baud rate is 115200.
The pin settings are as follows:
Project - setting, ToolChain/IDE select SW4STM32, note that there can be no spaces in the project name, it is best not to use Chinese.
check here
After saving, click the Generate Code icon on the taskbar
After the generation is completed, click "Open Project" in the pop-up dialog box, System Workbench automatically opens Eclipse, imports and opens the project, and then expands the project tree,
Double-click i2c.c in the Src folder to advance the I2C clock initialization to the front of the GPIO (this is the bug we need to modify):
void HAL_I2C_MspInit(I2C_HandleTypeDef* i2cHandle)
{
GPIO_InitTypeDef GPIO_InitStruct;
if(i2cHandle->Instance==I2C2)
{
/* USER CODE BEGIN I2C2_MspInit 0 */
__HAL_RCC_I2C2_CLK_ENABLE(); //By default, this clock initialization code is placed after GPIO initialization and needs to be adjusted here, that is, before GPIO initialization
/* USER CODE END I2C2_MspInit 0 */
/**I2C2 GPIO Configuration
PB10 ------> I2C2_SCL
PB11 ------> I2C2_SDA
*/
GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_11;
GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
HAL_GPIO_Init (GPIOB, & GPIO_InitStruct);
/* I2C2 clock enable */
// __HAL_RCC_I2C2_CLK_ENABLE();//By default this clock initialization code is placed here, it needs to be commented out here
/* USER CODE BEGIN I2C2_MspInit 1 */
/* USER CODE END I2C2_MspInit 1 */
}
}
Then edit main.c. First, we need to use printf to output some information and redirect it to the serial port. Referring to the previous tutorial, we make the following modifications:
Also don't forget to copy the STM32Cube_FW_F1_V1.6.0\Projects\STM3210C_EVAL\Examples\UART\UART_Printf\syscalls.c file to the src directory
/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*/
#ifdef __GNUC__
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif
/* USER CODE END PFP */
/* USER CODE BEGIN 0 */
PUTCHAR_PROTOTYPE
{
HAL_UART_Transmit(&huart1 , (uint8_t *)&ch, 1, 0xFFFF);
return ch;
}
/* USER CODE END 0 */
AT24C02 is an EEPROM with 256 Byte (ie 2Kbit). First define the device address and read and write variables
/* USER CODE BEGIN PV */ /* Private variables ---------------------------------------------------------*/ #define ADDR_AT24C02_Write 0xA0 #define ADDR_AT24C02_Read 0xA1 uint8_t I2C_Buffer_Write[256]; uint8_t I2C_Buffer_Read[256]; uint16_t i; /* USER CODE END PV */
256 bytes we fill 0x00 to 0xFF in order, we use the following function to write
HAL_I2C_Mem_Write(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint16_t MemAddress, uint16_t MemAddSize, uint8_t *pData, uint16_t Size, uint32_t Timeout), the meanings are as follows:
I2C_HandleTypeDef *hi2c -- handle of IIC mA uint16_t DevAddress
-- external address of IIC device
The internal address of the IIC device
uint16_t MemAddSize -- the way to read and write the internal address, generally use the I2C_MEMADD_SIZE_8BIT method,
note that there are only two options: I2C_MEMADD_SIZE_8BIT or I2C_MEMADD_SIZE_16BIT
uint8_t *pData -- written array or pointer
uint16_t Size -- written bytes number!
uint32_t Timeout -- timeout
Reading the specification of AT24C02, we can see that the 2Kbit of AT24C02 is divided into 32 pages, each page is 8 bytes. And EEPROM has a way to write by page, not by byte. So our example uses the page-by-page write method, which is divided into 32 writes. Note that it needs a delay of 5ms after each write, which is the requirement of AT24C02.
So the parameters should be chosen as follows:
I2C_HandleTypeDef *hi2c -- &hi2c2 // I2C2
uint16_t DevAddress --ADDR_AT24C02_Write //That is 0xA0, this is the write address, the read address is the write address + 1
uint16_t MemAddress --i //Write 8 bytes each time, so increase 8 from 0
uint16_t MemAddSize --I2C_MEMADD_SIZE_8BIT / / The way to read and write the internal address, the screenshot of the specification above also shows that it is the 8BIT method
uint8_t *pData --I2C_Buffer_Write+i , because the array is a pointer, so you can also use (uint8_t*)(&(I2C_Buffer_Write[i]))
or &(I2C_Buffer_Write[i])
uint16_t Size -- 8//Write one page at a time, as mentioned above, it is 8 bytes
uint32_t Timeout -- 1000//1000 or above, some people also use 0xFFFF.
After each page is written, the serial port prints the success message.
/* USER CODE BEGIN 3 */
/* USER CODE BEGIN 2 */
printf("\r\n \r\n*********STM32CubeMX I2C AT24C02 Example*********\r\n");
printf("\r\n I2C Write Buffer:\r\n");
for(i=0; i<256; i++)
{
I2C_Buffer_Write[i]=i; /* WriteBuffer Initialization */
printf("%02X ", I2C_Buffer_Write[i]);
}
/* write data to AT24C02 */
for(i=0; i<256; i=i+8)
// for(i=0; i<256; i++)
{
/*
*
/* The following three statements can be written correctly
*Write 8 bytes each time
*/
// if (HAL_I2C_Mem_Write(&hi2c2, ADDR_AT24C02_Write, i, I2C_MEMADD_SIZE_8BIT,I2C_Buffer_Write+i,8, 10000) == HAL_OK)
// if (HAL_I2C_Mem_Write(&hi2c2, ADDR_AT24C02_Write, i, I2C_MEMADD_SIZE_8BIT,(uint8_t*)(&(I2C_Buffer_Write[i])),8, 10000) == HAL_OK)
if (HAL_I2C_Mem_Write(&hi2c2, ADDR_AT24C02_Write, i, I2C_MEMADD_SIZE_8BIT,&(I2C_Buffer_Write[i]),8, 1000) == HAL_OK)
{
printf("\r\n Byte %02d to Byte %02d Write OK",i,i+8);
HAL_Delay(5);//After writing, it needs to delay 5ms, this can not be less
}
else
printf("\r\n Byte %02d to Byte %02d Write Failed",i,i+8);
}
After writing, we read the EEPROM value and print it to the serial port. There is no page limit for reading, and we can read all 256 bytes at a time. Read using the following command:
HAL_I2C_Mem_Read(&hi2c2, ADDR_AT24C02_Read, 0, I2C_MEMADD_SIZE_8BIT,I2C_Buffer_Read,256, 1000);
/* read data from EEPROM */
printf("\r\n Reading from AT24C02:\r\n");
HAL_I2C_Mem_Read(&hi2c2, ADDR_AT24C02_Read, 0, I2C_MEMADD_SIZE_8BIT,I2C_Buffer_Read,256, 1000);
for(i=0; i<256; i++)
{
printf("0x%02X ",I2C_Buffer_Read[i]);
}
It is also possible to do a direct memory comparison to see if the read and write are the same. :
if(memcmp(I2C_Buffer_Read,I2C_Buffer_Write,256) == 0 ) /* check data */
printf("\r\n AT24C02 Read Test OK\r\n");
else
printf("\r\n AT24C02 Read Test Failed\r\n");
Then right-click the project, select Properties, Run-Debug Settings, click New on the right, and select Ac6 STM32 Debugging in the pop-up dialog box.
Then click on the Run diagram on the taskbar, of course, an error will be reported. Please see another blog of mine (https://blog.csdn.net/toopoo/article/details/79680323), so you need to right-click the project name Run. cfg , rename it,
Then right-click the project name in the project tree, select "Propeties", then click "Search Project" in Run/Debug Settings-select the project name-Edit-Main-C/C++Application, and then select the default elf that appears document:
Then select the configuration file you renamed in Debugger-User Defined-Browse:
Then right-click on that new cfg file, select "Open With - Text Editor", and make the following changes:
source [find interface/stlink.cfg] 更改为 source [find interface/stlink-v2.cfg]
reset_config srst_only srst_nogate connect_assert_srst This line is changed to reset_config none
Then run it again and you're done.
You can see the following information from the serial port program:
*********STM32CubeMX I2C AT24C02 Example********* I2C Write Buffer: 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F 60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F 80 81 82 83 84 85 86 87 88 89 8A 8B 8C 8D 8E 8F 90 91 92 93 94 95 96 97 98 99 9A 9B 9C 9D 9E 9F A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 AA AB AC AD AE AF B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 BA BB BC BD BE BF C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 CA CB CC CD CE CF D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 DA DB DC DD DE DF E0 E1 E2 E3 E4 E5 E6 E7 E8 E9 EA EB EC ED EE EF F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE FF Byte 00 to Byte 07 Write OK Byte 08 to Byte 15 Write OK Byte 16 to Byte 23 Write OK Byte 24 to Byte 31 Write OK Byte 32 to Byte 39 Write OK Byte 40 to Byte 47 Write OK Byte 48 to Byte 55 Write OK Byte 56 to Byte 63 Write OK Byte 64 to Byte 71 Write OK Byte 72 to Byte 79 Write OK Byte 80 to Byte 87 Write OK Byte 88 to Byte 95 Write OK Byte 96 to Byte 103 Write OK Byte 104 to Byte 111 Write OK Byte 112 to Byte 119 Write OK Byte 120 to Byte 127 Write OK Byte 128 to Byte 135 Write OK Byte 136 to Byte 143 Write OK Byte 144 to Byte 151 Write OK Byte 152 to Byte 159 Write OK Byte 160 to Byte 167 Write OK Byte 168 to Byte 175 Write OK Byte 176 to Byte 183 Write OK Byte 184 to Byte 191 Write OK Byte 192 to Byte 199 Write OK Byte 200 to Byte 207 Write OK Byte 208 to Byte 215 Write OK Byte 216 to Byte 223 Write OK Byte 224 to Byte 231 Write OK Byte 232 to Byte 239 Write OK Byte 240 to Byte 247 Write OK Byte 248 to Byte 255 Write OK Reading from AT24C02: 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09 0x0A 0x0B 0x0C 0x0D 0x0E 0x0F 0x10 0x11 0x12 0x13 0x14 0x15 0x16 0x17 0x18 0x19 0x1A 0x1B 0x1C 0x1D 0x1E 0x1F 0x20 0x21 0x22 0x23 0x24 0x25 0x26 0x27 0x28 0x29 0x2A 0x2B 0x2C 0x2D 0x2E 0x2F 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x37 0x38 0x39 0x3A 0x3B 0x3C 0x3D 0x3E 0x3F 0x40 0x41 0x42 0x43 0x44 0x45 0x46 0x47 0x48 0x49 0x4A 0x4B 0x4C 0x4D 0x4E 0x4F 0x50 0x51 0x52 0x53 0x54 0x55 0x56 0x57 0x58 0x59 0x5A 0x5B 0x5C 0x5D 0x5E 0x5F 0x60 0x61 0x62 0x63 0x64 0x65 0x66 0x67 0x68 0x69 0x6A 0x6B 0x6C 0x6D 0x6E 0x6F 0x70 0x71 0x72 0x73 0x74 0x75 0x76 0x77 0x78 0x79 0x7A 0x7B 0x7C 0x7D 0x7E 0x7F 0x80 0x81 0x82 0x83 0x84 0x85 0x86 0x87 0x88 0x89 0x8A 0x8B 0x8C 0x8D 0x8E0x8F 0x90 0x91 0x92 0x93 0x94 0x95 0x96 0x97 0x98 0x99 0x9A 0x9B 0x9C 0x9D 0x9E 0x9F 0xA0 0xA1 0xA2 0xA3 0xA4 0xA5 0xA6 0xA7 0xA8 0xA9 0xAA 0xAB 0xAC 0xAD 0xAE 0xAF 0xB0 0xB1 0xB2 0xB3 0xB4 0xB5 0xB6 0xB7 0xB8 0xB9 0xBA 0xBB 0xBC 0xBD 0xBE 0xBF 0xC0 0xC1 0xC2 0xC3 0xC4 0xC5 0xC6 0xC7 0xC8 0xC9 0xCA 0xCB 0xCC 0xCD 0xCE 0xCF 0xD0 0xD1 0xD2 0xD3 0xD4 0xD5 0xD6 0xD7 0xD8 0xD9 0xDA 0xDB 0xDC 0xDD 0xDE 0xDF 0xE0 0xE1 0xE2 0xE3 0xE4 0xE5 0xE6 0xE7 0xE8 0xE9 0xEA 0xEB 0xEC 0xED 0xEE 0xEF 0xF0 0xF1 0xF2 0xF3 0xF4 0xF5 0xF6 0xF7 0xF8 0xF9 0xFA 0xFB 0xFC 0xFD 0xFE 0xFF0xAD 0xAE 0xAF 0xB0 0xB1 0xB2 0xB3 0xB4 0xB5 0xB6 0xB7 0xB8 0xB9 0xBA 0xBB 0xBC 0xBD 0xBE 0xBF 0xC0 0xC1 0xC2 0xC3 0xC4 0xC5 0xC6 0xC7 0xC8 0xC9 0xCA 0xCB 0xCC 0xCD 0xCE 0xCF 0xD0 0xD1 0xD2 0xD3 0xD4 0xD5 0xD6 0xD7 0xD8 0xD9 0xDA 0xDB 0xDC 0xDD 0xDE 0xDF 0xE0 0xE1 0xE2 0xE3 0xE4 0xE5 0xE6 0xE7 0xE8 0xE9 0xEA 0xEB 0xEC 0xED 0xEE 0xEF 0xF0 0xF1 0xF2 0xF3 0xF4 0xF5 0xF6 0xF7 0xF8 0xF9 0xFA 0xFB 0xFC 0xFD 0xFE 0xFF0xAD 0xAE 0xAF 0xB0 0xB1 0xB2 0xB3 0xB4 0xB5 0xB6 0xB7 0xB8 0xB9 0xBA 0xBB 0xBC 0xBD 0xBE 0xBF 0xC0 0xC1 0xC2 0xC3 0xC4 0xC5 0xC6 0xC7 0xC8 0xC9 0xCA 0xCB 0xCC 0xCD 0xCE 0xCF 0xD0 0xD1 0xD2 0xD3 0xD4 0xD5 0xD6 0xD7 0xD8 0xD9 0xDA 0xDB 0xDC 0xDD 0xDE 0xDF 0xE0 0xE1 0xE2 0xE3 0xE4 0xE5 0xE6 0xE7 0xE8 0xE9 0xEA 0xEB 0xEC 0xED 0xEE 0xEF 0xF0 0xF1 0xF2 0xF3 0xF4 0xF5 0xF6 0xF7 0xF8 0xF9 0xFA 0xFB 0xFC 0xFD 0xFE 0xFF0xEA 0xEB 0xEC 0xED 0xEE 0xEF 0xF0 0xF1 0xF2 0xF3 0xF4 0xF5 0xF6 0xF7 0xF8 0xF9 0xFA 0xFB 0xFC 0xFD 0xFE 0xFF0xEA 0xEB 0xEC 0xED 0xEE 0xEF 0xF0 0xF1 0xF2 0xF3 0xF4 0xF5 0xF6 0xF7 0xF8 0xF9 0xFA 0xFB 0xFC 0xFD 0xFE 0xFF AT24C02 Read Test OK