stm32f407 iic 9685驱动16通道PWM

要实现16通道PWM输出，可以使用STM32F407的定时器和GPIO模块，以及I2C模块驱动PCA9685芯片实现。具体步骤如下：

1. 配置STM32F407的GPIO模块，将16个PWM输出引脚配置为输出模式。

2. 配置STM32F407的定时器模块，选择合适的定时器，将其配置为PWM模式，设置PWM频率和占空比。

3. 使用STM32F407的I2C模块与PCA9685芯片进行通信，写入相应的寄存器配置信息，使其工作在PWM模式下。

4. 将16个PWM输出引脚分别连接到外部设备，实现PWM输出。

需要注意的是，在使用PCA9685芯片时，需要先对其进行初始化配置，设置PWM频率和PWM分辨率等参数，然后才能进行PWM输出。具体的代码实现可以参考PCA9685的数据手册和STM32F407的开发文档。

相关问题

stm32f407 iic 9685驱动16通道PWM的代码

以下是使用STM32F407和I2C驱动PCA9685的16通道PWM的基本代码：

#include "stm32f4xx.h"
#include "i2c.h"

#define PCA9685_ADDRESS 0x40

#define MODE1          0x00
#define MODE2          0x01
#define PRESCALE       0xFE
#define LED0_ON_L      0x06

#define ENABLE_AUTO_INC 0x20
#define SLEEP           0x10
#define ALLCALL         0x01

#define PWM_FREQ 50

#define MIN_PULSE_WIDTH 64
#define MAX_PULSE_WIDTH 4096

void PCA9685_init(void);
void PCA9685_setPWM(uint8_t num, uint16_t on, uint16_t off);
void PCA9685_setServoPulse(uint8_t num, double pulse);

int main(void)
{
    SystemInit();
    I2C_init();
    PCA9685_init();

    while(1)
    {
        // set servo position to 0 degrees
        PCA9685_setServoPulse(0, 500);
        // wait for 1 second
        for(uint32_t i = 0; i < 10000000; i++);
        // set servo position to 90 degrees
        PCA9685_setServoPulse(0, 1500);
        // wait for 1 second
        for(uint32_t i = 0; i < 10000000; i++);
        // set servo position to 180 degrees
        PCA9685_setServoPulse(0, 2500);
        // wait for 1 second
        for(uint32_t i = 0; i < 10000000; i++);
    }
}

void PCA9685_init(void)
{
    I2C_start();
    I2C_write(PCA9685_ADDRESS << 1);
    I2C_write(MODE1);
    I2C_write(ENABLE_AUTO_INC | ALLCALL);
    I2C_stop();

    I2C_start();
    I2C_write(PCA9685_ADDRESS << 1);
    I2C_write(MODE2);
    I2C_write(SLEEP);
    I2C_stop();

    uint8_t prescale = (uint8_t)((25000000 / (4096 * PWM_FREQ)) - 1);

    I2C_start();
    I2C_write(PCA9685_ADDRESS << 1);
    I2C_write(PRESCALE);
    I2C_write(prescale);
    I2C_stop();

    I2C_start();
    I2C_write(PCA9685_ADDRESS << 1);
    I2C_write(MODE1);
    I2C_write(ALLCALL);
    I2C_stop();

    for(uint8_t i = 0; i < 16; i++)
    {
        PCA9685_setPWM(i, 0, 0);
    }
}

void PCA9685_setPWM(uint8_t num, uint16_t on, uint16_t off)
{
    I2C_start();
    I2C_write(PCA9685_ADDRESS << 1);
    I2C_write(LED0_ON_L + (4 * num));
    I2C_write(on & 0xFF);
    I2C_write(on >> 8);
    I2C_write(off & 0xFF);
    I2C_write(off >> 8);
    I2C_stop();
}

void PCA9685_setServoPulse(uint8_t num, double pulse)
{
    pulse = (pulse < MIN_PULSE_WIDTH) ? MIN_PULSE_WIDTH : pulse;
    pulse = (pulse > MAX_PULSE_WIDTH) ? MAX_PULSE_WIDTH : pulse;

    uint16_t value = (uint16_t)(pulse * 4096 / 20000);

    PCA9685_setPWM(num, 0, value);
}

需要注意的是，上述代码中的`I2C_init()`和`I2C_start()`等函数都需要根据具体的硬件平台和I2C驱动程序进行修改。此外，代码中使用的PWM频率为50Hz，可根据需要进行修改。另外，`PCA9685_setServoPulse()`函数用于设置舵机的位置，可根据具体的舵机型号进行修改。

stm32f407使用iic2驱动Pca9685的16通道Pwm代码

以下是使用I2C2驱动PCA9685的16通道PWM代码，需要先初始化I2C2和PCA9685：

#include "stm32f4xx.h"

#define PCA9685_ADDR 0x40 // PCA9685的I2C地址

void I2C2_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct;
    I2C_InitTypeDef I2C_InitStruct;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_OD;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOB, &GPIO_InitStruct);

    GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_I2C2);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_I2C2);

    I2C_DeInit(I2C2);
    I2C_InitStruct.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStruct.I2C_OwnAddress1 = 0x00;
    I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_InitStruct.I2C_ClockSpeed = 100000;
    I2C_Init(I2C2, &I2C_InitStruct);

    I2C_Cmd(I2C2, ENABLE);
}

void PCA9685_Init(void)
{
    uint8_t data[2];

    data[0] = 0x00; // MODE1寄存器地址
    data[1] = 0x01; // 设置PCA9685为普通模式
    I2C_GenerateSTART(I2C2, ENABLE);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT));
    I2C_Send7bitAddress(I2C2, PCA9685_ADDR, I2C_Direction_Transmitter);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
    I2C_SendData(I2C2, data[0]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_SendData(I2C2, data[1]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_GenerateSTOP(I2C2, ENABLE);

    data[0] = 0xFE; // PRE_SCALE寄存器地址
    data[1] = 0x03; // 设置PWM时钟频率为50Hz
    I2C_GenerateSTART(I2C2, ENABLE);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT));
    I2C_Send7bitAddress(I2C2, PCA9685_ADDR, I2C_Direction_Transmitter);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
    I2C_SendData(I2C2, data[0]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_SendData(I2C2, data[1]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_GenerateSTOP(I2C2, ENABLE);

    data[0] = 0x00; // MODE1寄存器地址
    data[1] = 0x81; // 设置PCA9685为自动增量模式
    I2C_GenerateSTART(I2C2, ENABLE);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT));
    I2C_Send7bitAddress(I2C2, PCA9685_ADDR, I2C_Direction_Transmitter);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
    I2C_SendData(I2C2, data[0]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_SendData(I2C2, data[1]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_GenerateSTOP(I2C2, ENABLE);
}

void PCA9685_SetPWM(uint8_t channel, uint16_t on, uint16_t off)
{
    uint8_t data[5];

    data[0] = 0x06 + 4 * channel; // LED0_ON_L寄存器地址
    data[1] = on & 0xFF; // LED0_ON_L
    data[2] = on >> 8; // LED0_ON_H
    data[3] = off & 0xFF; // LED0_OFF_L
    data[4] = off >> 8; // LED0_OFF_H

    I2C_GenerateSTART(I2C2, ENABLE);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT));
    I2C_Send7bitAddress(I2C2, PCA9685_ADDR, I2C_Direction_Transmitter);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
    I2C_SendData(I2C2, data[0]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_SendData(I2C2, data[1]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_SendData(I2C2, data[2]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_SendData(I2C2, data[3]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_SendData(I2C2, data[4]);
    while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    I2C_GenerateSTOP(I2C2, ENABLE);
}

int main(void)
{
    I2C2_Init();
    PCA9685_Init();

    while (1)
    {
        // 设置PWM输出
        PCA9685_SetPWM(0, 0, 2048); // 50%占空比
        PCA9685_SetPWM(1, 0, 4096); // 100%占空比
    }
}