求教：用ArduinoMega2560完成11路PWM采集和4路PWM输出
尊敬的各位大侠、专家、高手：我打算采用ArduinoMega2560板子采集11路PWM输入，然后用USB口通过串口协议发送给手机解算后，再发回Arduino，由arduino生成4路PWM波，驱动小车的四个轮子旋转。
现在已经搞了一个初步的代码，其中有5路采用查询方式采集，6路采用外部中断采集。然而，问题是当手机从串口发回数据时会影响Arduino的PWM波采集值，大约有10%的概率采集到的PWM波会突然变小一些，导致采集的误差发生，波动较大。
请问各位尊敬的大侠、专家、高手改如何解决？不胜感激。
int ppm1 = 2;
int ppm2 = 3;
int ppm3 = 18;
int ppm4 = 19;
int ppm5 = 20;
int ppm6 = 21;
int pwmInput1 = 0;
int pwmInput2 = 0;
int pwmInput3 = 0;
int pwmInput4 = 0;
int pwmInput5 = 0;
unsigned long rc1_PulseStartTicks,rc2_PulseStartTicks,rc3_PulseStartTicks,rc4_PulseStartTicks,rc5_PulseStartTicks,rc6_PulseStartTicks;
volatile int rc1_val, rc2_val,rc3_val, rc4_val,rc5_val,rc6_val;
float startTime = 0;
void setup() {
Serial.begin(115200);
////PPM inputs from RC receiver
pinMode(ppm1, INPUT);
pinMode(ppm2, INPUT);
pinMode(ppm3, INPUT);
pinMode(ppm4, INPUT);
pinMode(ppm5, INPUT);
// 电平变化即触发中断
attachInterrupt(0, rc1, CHANGE);
attachInterrupt(1, rc2, CHANGE);
attachInterrupt(5, rc3, CHANGE);
attachInterrupt(4, rc4, CHANGE);
attachInterrupt(3, rc5, CHANGE);
attachInterrupt(2, rc6, CHANGE);
pinMode(31,INPUT);
pinMode(33,INPUT);
pinMode(35,INPUT);
pinMode(37,INPUT);
pinMode(39,INPUT);
startTime = millis();
}
void rc1()
{
// did the pin change to high or low?
if (digitalRead(ppm1 ) == HIGH)
rc1_PulseStartTicks = micros(); // store the current micros() value
else
rc1_val = micros() - rc1_PulseStartTicks;
map(rc1_val,900,2100,0,255);
}
void rc2()
{
// did the pin change to high or low?
if (digitalRead( ppm2 ) == HIGH)
rc2_PulseStartTicks = micros();
else
rc2_val = micros() - rc2_PulseStartTicks;
map(rc2_val,900,2100,0,255);
}
void rc3()
{
// did the pin change to high or low?
if (digitalRead( ppm3 ) == HIGH)
rc3_PulseStartTicks = micros();
else
rc3_val = micros() - rc3_PulseStartTicks;
map(rc3_val,900,2100,0,255);
}
void rc4()
{
// did the pin change to high or low?
if (digitalRead( ppm4 ) == HIGH)
rc4_PulseStartTicks = micros();
else
rc4_val = micros() - rc4_PulseStartTicks;
map(rc4_val,900,2100,0,255);
}
void rc5()
{
// did the pin change to high or low?
if (digitalRead( ppm5 ) == HIGH)
rc5_PulseStartTicks = micros();
else
rc5_val = micros() - rc5_PulseStartTicks;
map(rc5_val,900,2100,0,255);
}
void rc6()
{
// did the pin change to high or low?
if (digitalRead( ppm6 ) == HIGH)
rc6_PulseStartTicks = micros();
else
rc6_val = micros() - rc6_PulseStartTicks;
map(rc6_val,900,2100,0,255);
}
unsigned long time = 0;
int loopCounter = 1;
void loop() {
int checkSum = 0;
delayMicroseconds(17500);
pwmInput1 = pulseIn(31, HIGH);
delayMicroseconds(500);
pwmInput2 = pulseIn(33,HIGH);
delayMicroseconds(500);
pwmInput3 = pulseIn(35,HIGH);
delayMicroseconds(500);
pwmInput4 = pulseIn(37, HIGH);
delayMicroseconds(500);
pwmInput5 = pulseIn(39, HIGH);
delayMicroseconds(500);
pwmInput1 = map(pwmInput1,900,2100,0,255);
pwmInput2 = map(pwmInput2,900,2100,0,255);
pwmInput3 = map(pwmInput3,900,2100,0,255);
pwmInput4 = map(pwmInput4,900,2100,0,255);
pwmInput5 = map(pwmInput5,900,2100,0,255);
checkSum = pwmInput1+pwmInput2+pwmInput3+pwmInput4+pwmInput5+rc1_val+rc2_val+rc3_val+rc4_val+rc5_val+rc6_val;
checkSum = checkSum%256;
// //Send to Console
// Serial.print("No.");
// Serial.print(loopCounter);
// Serial.print('\t');
// Serial.print("Time");
// Serial.print((millis()-startTime)/1000);
// Serial.print('\t');
// Serial.print(pwmInput1);
// Serial.print('\t');
// Serial.print(pwmInput2);
// Serial.print('\t');
// Serial.print(pwmInput3);
// Serial.print('\t');
// Serial.print(pwmInput4);
// Serial.print('\t');
// Serial.print(pwmInput5);
// Serial.print('\t');
// Serial.print(rc1_val);
// Serial.print('\t');
// Serial.print(rc2_val);
// Serial.print('\t');
// Serial.print(rc3_val);
// Serial.print('\t');
// Serial.print(rc4_val);
// Serial.print('\t');
// Serial.print(rc5_val);
// Serial.print('\t');
// Serial.print(rc6_val);
// Serial.print('\n');
// loopCounter ++;
//Send to Android
Serial.write(0xFE);
Serial.write(0xFE);
Serial.write(0xFE);
Serial.write((byte)loopCounter);
Serial.write((byte)pwmInput1);
Serial.write((byte)pwmInput2);
Serial.write((byte)pwmInput3);
Serial.write((byte)pwmInput4);
Serial.write((byte)pwmInput5);
Serial.write((byte)rc1_val);
Serial.write((byte)rc2_val);
Serial.write((byte)rc3_val);
Serial.write((byte)rc4_val);
Serial.write((byte)rc5_val);
Serial.write((byte)rc6_val);
Serial.write((byte)checkSum);
Serial.write(0xFE);
Serial.write(0xFE);
Serial.write(0xFE);
Serial.write((byte)loopCounter);
Serial.write((byte)pwmInput1);
Serial.write((byte)pwmInput2);
Serial.write((byte)pwmInput3);
Serial.write((byte)pwmInput4);
Serial.write((byte)pwmInput5);
Serial.write((byte)rc1_val);
Serial.write((byte)rc2_val);
Serial.write((byte)rc3_val);
Serial.write((byte)rc4_val);
Serial.write((byte)rc5_val);
Serial.write((byte)rc6_val);
Serial.write((byte)checkSum);
Serial.write(0xFE);
Serial.write(0xFE);
Serial.write(0xFE);
Serial.write((byte)loopCounter);
Serial.write((byte)pwmInput1);
Serial.write((byte)pwmInput2);
Serial.write((byte)pwmInput3);
Serial.write((byte)pwmInput4);
Serial.write((byte)pwmInput5);
Serial.write((byte)rc1_val);
Serial.write((byte)rc2_val);
Serial.write((byte)rc3_val);
Serial.write((byte)rc4_val);
Serial.write((byte)rc5_val);
Serial.write((byte)rc6_val);
Serial.write((byte)checkSum);
loopCounter++;
if (loopCounter==255)
loopCounter = 0;
}
不懂帮顶，:lol 代码好长，有点看不懂 接收 PWM 的方法有問題:
1) interrupt 之間互相影響下，時間不準確
2) isr 中不可以用時間的函數，i.e. micro()
我之前出過一個帖，研究如何讀取 pwm 值的，有興趣可看看。
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