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制造工程实践使用
Diff: PCA9685.cpp
- Revision:
- 2:1d858fcb3cb5
- Parent:
- 0:c7f4744deec3
--- a/PCA9685.cpp Fri Jul 24 09:03:58 2015 +0000 +++ b/PCA9685.cpp Thu Oct 24 06:30:59 2019 +0000 @@ -1,17 +1,17 @@ #include "PCA9685.h" #include "mbed.h" PCA9685::PCA9685(PinName sda, PinName scl, int addr) : i2c(sda, scl), _i2caddr(addr) {} - -void PCA9685::begin(void) +//定义引脚与地址 +void PCA9685::begin(void)//初始化 { reset(); } -void PCA9685::frequencyI2C(int freq) +void PCA9685::frequencyI2C(int freq)//初始化 { i2c.frequency(freq); } -void PCA9685::write8(uint8_t address, uint8_t data) +void PCA9685::write8(uint8_t address, uint8_t data)//写函数 { char cmd[2]; cmd[0] = address; @@ -19,7 +19,7 @@ i2c.write(_i2caddr, cmd, 2); } -char PCA9685::read8(char address) +char PCA9685::read8(char address)//读函数 { i2c.write(_i2caddr, &address, 1); char rtn; @@ -27,21 +27,21 @@ return rtn; } -void PCA9685::reset(void) +void PCA9685::reset(void)//复位 { write8(PCA9685_MODE1, 0x0); } -void PCA9685::setPrescale(uint8_t prescale) { +void PCA9685::setPrescale(uint8_t prescale) { uint8_t oldmode = read8(PCA9685_MODE1); uint8_t newmode = (oldmode&0x7F) | 0x10; // sleep write8(PCA9685_MODE1, newmode); // go to sleep wait_ms(5); - write8(PCA9685_PRESCALE, prescale); // set the prescaler + write8(PCA9685_PRESCALE, prescale); // 设置预缩放 write8(PCA9685_MODE1, oldmode); wait_ms(5); write8(PCA9685_MODE1, oldmode | 0xa1); } -void PCA9685::setPWMFreq(float freq) +void PCA9685::setPWMFreq(float freq) //设置频率 { float prescaleval = 25000000; prescaleval /= 4096;