如何让Python（通过串口）发送的数据等待Arduino完成当前任务？
How to make data sent by Python (via serial connection) wait for Arduino to finish current task?
我尝试让我的 Arduino 微控制器和我的 Mac 一起通话，并创建了一个功能性串行连接。我的电脑正在向我的 Arduino 发送数据，当我的 Arduino 准备好接收新数据时，我的 Arduino 正在发送 '1'。
我创建了一个 if-else 语句（下面的 Python 脚本），它要么向 Arduino 发送一行新数据，要么等待 Arduino 准备好接收新行数据。
问题是 Python 脚本第一部分中的 ser.read() 总是 returns '1'，这意味着脚本正在更快地发送各个数据行比 Arduino 连接的步进电机可能做出反应。
在 Arduino 脚本中，您可以看到我在 serialEvent() 函数的第一行发送了状态状态，在我的世界中，这应该让 Arduino 在新的 "task" 来了。但是，由于某种原因它不起作用。有人可以帮我吗？
Python 脚本
import os
import time
import serial
# Name of csv file with drawing coordinates
csvFile = "scaled_coordinates.csv"
# Create serial connection
ser = serial.Serial(port='/dev/tty.usbserial-A9005bDh', baudrate=9600)
wd = os.getcwd()
myFile = open(wd + "/coordinates/" + csvFile)
state = '1'
while True: # Exits when there is no more lines to read
if state == '0': # Wait for Arduino to be ready
state = ser.read()
elif state == '1': # Send one more line to Arduino
line = myFile.readline()
if not line:
break
print line
ser.write(line)
#time.sleep(1)
state = '0' # Wait for Arduino before reading next line
myFile.close
Arduino loop 函数
void loop() {
serialEvent(); // Call the serial function
if (coord_complete) {
// Steps to move from currrent to new point
target1 = steps(x_current, y_current, x_new, y_new, 1);
target2 = steps(x_current, y_current, x_new, y_new, 2);
// Start moving
stepper1.move(target1);
stepper2.move(target2);
// Update current position
x_current = x_new;
y_current = y_new;
// Reset variables
x_complete = false;
y_complete = false;
coord_complete = false;
}
// Stay in while loop until steppermotors is done
while ((stepper1.distanceToGo() != 0) && (stepper2.distanceToGo() != 0)) {
stepper1.run();
stepper2.run();
}
}
Arduino serialEvent 函数
void serialEvent() {
Serial.write('1'); // Tell Python that Arduino is ready for one more line
while (Serial.available() && coord_complete == false) {
char ch = Serial.read(); // Get new character
Serial.print(ch);
// If digit; add it to coord_string
if (isDigit(ch)) {
coord_string[index++] = ch;
// Else if ch is ","; then rename to x_new
} else if (ch == ',') {
coord_string[index++] = NULL; // Finish coord_string
x_new = atoi(coord_string); // Convert to integer
x_complete = true; // Change x_complete to true
index = 0; // Reset index
memset(coord_string, 0, sizeof(coord_string)); // Reset coord_string
// Else if ch is a new line; then rename as y_new
} else if (ch == ';') {
//Serial.write('0');
coord_string[index++] = NULL;
y_new = atoi(coord_string);
y_complete = true;
index = 0;
memset(coord_string, 0, sizeof(coord_string));
}
// Ends while-loop when true
coord_complete = x_complete * y_complete;
}
}
编辑
当前的 Python 代码如下所示：
import os
import time
import serial
# Name of csv file with drawing coordinates
csvGraphic = "Scaled_coordinates.csv"
# Create serial connection
ser = serial.Serial(port='/dev/tty.usbserial-A9005bDh', baudrate=9600)
wd = os.getcwd()
myFile = open(wd + "/graphics/" + csvGraphic)
state = '1'
while True: # Exits when there is no more lines to read
print "state", state
if state == '0': # Wait for Arduino to be ready
state = str(ser.read())
elif state == '1': # Send one more line to Arduino
line = myFile.readline()
if not line:
ser.close()
break
print line
ser.write(line)
state = '0' # Wait for Arduino before reading next line
ser.close()
myFile.close
Python 输出如下所示。代码一次性执行，无需等待 Arduino。 state = str(ser.read()) 行似乎读取了某种串行缓冲区中的数据。我猜解决方案是清除缓冲区。我只是不知道如何。
state 1
239,275;
state 0
state 1
1100,275;
state 0
state 1
300,400;
state 0
state 1
200,400;
state 0
state 1
200,300;
state 0
state 1
[Finished in 0.1s]
我想我找到了。您的 SerialEvent() 在 loop 的开头被调用。它做的第一件事是 write('1') 意味着每次执行 loop 时它会告诉您的 python 代码它已准备好接受新指令（即使没有给出指令！）并用 lot 填充缓冲区你一个一个读的'1'
试试这个：
void SerialEvent(){
if((stepper1.distanceToGo() == 0) && (stepper2.distanceToGo() == 0)){
Serial.write('1');
}
//Rest of the function
另外我认为在你的循环结束时你想要
while((stepper1.distanceToGo() != 0) || (stepper2.distanceToGo() != 0))
而不是while((stepper1.distanceToGo() != 0) && (stepper2.distanceToGo() != 0))
感谢 E 先生，我找到了解决方案。基本上我需要在读取或写入之前清除串行缓冲区（flushInput() 和 flushOutput() in Python 和 flush() in Arduino）Python 和 Arduino 之间的新数据.此外，Python 和 Arduino 代码中的一个小延迟是必要的，以使其工作。
Pyhton
import os
import time
import serial
# Name of csv file with drawing coordinates
fileName = "coordinates.csv"
# Create serial connection
ser = serial.Serial(port='/dev/tty.usbserial-A9005bDh', baudrate=9600)
wd = os.getcwd()
myFile = open(wd + "/graphics/" + fileName)
#num_lines = sum(1 for line in myFile)
state = '0'
idx = 0
while True: # Exits when there is no more lines to read
#print "state", state
while state == '0': # Wait for Arduino to be ready
ser.flushInput() # Clear input buffer
state = str(ser.read())
if state == '1': # Send one more line to Arduino
line = myFile.readline()
if not line:
break
print "Coordinate", idx
print line
ser.flushOutput() # Clear output buffer
ser.write(line)
time.sleep(0.1)
idx = idx + 1
state = '0' # Set waiting flag – make Arduino wait for next line
ser.close()
myFile.close
Arduino serialEvent 函数
void serialEvent() {
if ((stepper1.distanceToGo() == 0) && (stepper2.distanceToGo() == 0)) {
Serial.write('1'); // Tell Python that Arduino is ready for one more line
delay(10);
Serial.flush(); // clear buffer
}
while (Serial.available() && coord_complete == false) {
char ch = Serial.read(); // Get new character
Serial.flush();
// If digit; add it to coord_string
if (isDigit(ch)) {
coord_string[index++] = ch;
// Else if ch is ","; then rename to x_new
} else if (ch == ',') {
coord_string[index++] = NULL; // Finish coord_string
x_new = atoi(coord_string); // Convert to integer
x_complete = true; // Change x_complete to true
index = 0; // Reset index
memset(coord_string, 0, sizeof(coord_string)); // Reset coord_string
// Else if ch is a new line; then rename as y_new
} else if (ch == ';') {
//Serial.write('0');
coord_string[index++] = NULL;
y_new = atoi(coord_string);
y_complete = true;
index = 0;
memset(coord_string, 0, sizeof(coord_string));
}
// Ends while-loop when true
coord_complete = x_complete * y_complete;
}
}
我尝试让我的 Arduino 微控制器和我的 Mac 一起通话，并创建了一个功能性串行连接。我的电脑正在向我的 Arduino 发送数据，当我的 Arduino 准备好接收新数据时，我的 Arduino 正在发送 '1'。
我创建了一个 if-else 语句（下面的 Python 脚本），它要么向 Arduino 发送一行新数据，要么等待 Arduino 准备好接收新行数据。
问题是 Python 脚本第一部分中的 ser.read() 总是 returns '1'，这意味着脚本正在更快地发送各个数据行比 Arduino 连接的步进电机可能做出反应。
在 Arduino 脚本中，您可以看到我在 serialEvent() 函数的第一行发送了状态状态，在我的世界中，这应该让 Arduino 在新的 "task" 来了。但是，由于某种原因它不起作用。有人可以帮我吗？
Python 脚本
import os
import time
import serial
# Name of csv file with drawing coordinates
csvFile = "scaled_coordinates.csv"
# Create serial connection
ser = serial.Serial(port='/dev/tty.usbserial-A9005bDh', baudrate=9600)
wd = os.getcwd()
myFile = open(wd + "/coordinates/" + csvFile)
state = '1'
while True: # Exits when there is no more lines to read
if state == '0': # Wait for Arduino to be ready
state = ser.read()
elif state == '1': # Send one more line to Arduino
line = myFile.readline()
if not line:
break
print line
ser.write(line)
#time.sleep(1)
state = '0' # Wait for Arduino before reading next line
myFile.close
Arduino loop 函数
void loop() {
serialEvent(); // Call the serial function
if (coord_complete) {
// Steps to move from currrent to new point
target1 = steps(x_current, y_current, x_new, y_new, 1);
target2 = steps(x_current, y_current, x_new, y_new, 2);
// Start moving
stepper1.move(target1);
stepper2.move(target2);
// Update current position
x_current = x_new;
y_current = y_new;
// Reset variables
x_complete = false;
y_complete = false;
coord_complete = false;
}
// Stay in while loop until steppermotors is done
while ((stepper1.distanceToGo() != 0) && (stepper2.distanceToGo() != 0)) {
stepper1.run();
stepper2.run();
}
}
Arduino serialEvent 函数
void serialEvent() {
Serial.write('1'); // Tell Python that Arduino is ready for one more line
while (Serial.available() && coord_complete == false) {
char ch = Serial.read(); // Get new character
Serial.print(ch);
// If digit; add it to coord_string
if (isDigit(ch)) {
coord_string[index++] = ch;
// Else if ch is ","; then rename to x_new
} else if (ch == ',') {
coord_string[index++] = NULL; // Finish coord_string
x_new = atoi(coord_string); // Convert to integer
x_complete = true; // Change x_complete to true
index = 0; // Reset index
memset(coord_string, 0, sizeof(coord_string)); // Reset coord_string
// Else if ch is a new line; then rename as y_new
} else if (ch == ';') {
//Serial.write('0');
coord_string[index++] = NULL;
y_new = atoi(coord_string);
y_complete = true;
index = 0;
memset(coord_string, 0, sizeof(coord_string));
}
// Ends while-loop when true
coord_complete = x_complete * y_complete;
}
}
编辑
当前的 Python 代码如下所示：
import os
import time
import serial
# Name of csv file with drawing coordinates
csvGraphic = "Scaled_coordinates.csv"
# Create serial connection
ser = serial.Serial(port='/dev/tty.usbserial-A9005bDh', baudrate=9600)
wd = os.getcwd()
myFile = open(wd + "/graphics/" + csvGraphic)
state = '1'
while True: # Exits when there is no more lines to read
print "state", state
if state == '0': # Wait for Arduino to be ready
state = str(ser.read())
elif state == '1': # Send one more line to Arduino
line = myFile.readline()
if not line:
ser.close()
break
print line
ser.write(line)
state = '0' # Wait for Arduino before reading next line
ser.close()
myFile.close
Python 输出如下所示。代码一次性执行，无需等待 Arduino。 state = str(ser.read()) 行似乎读取了某种串行缓冲区中的数据。我猜解决方案是清除缓冲区。我只是不知道如何。
state 1
239,275;
state 0
state 1
1100,275;
state 0
state 1
300,400;
state 0
state 1
200,400;
state 0
state 1
200,300;
state 0
state 1
[Finished in 0.1s]
我想我找到了。您的 SerialEvent() 在 loop 的开头被调用。它做的第一件事是 write('1') 意味着每次执行 loop 时它会告诉您的 python 代码它已准备好接受新指令（即使没有给出指令！）并用 lot 填充缓冲区你一个一个读的'1'
试试这个：
void SerialEvent(){
if((stepper1.distanceToGo() == 0) && (stepper2.distanceToGo() == 0)){
Serial.write('1');
}
//Rest of the function
另外我认为在你的循环结束时你想要
while((stepper1.distanceToGo() != 0) || (stepper2.distanceToGo() != 0))
而不是while((stepper1.distanceToGo() != 0) && (stepper2.distanceToGo() != 0))
感谢 E 先生，我找到了解决方案。基本上我需要在读取或写入之前清除串行缓冲区（flushInput() 和 flushOutput() in Python 和 flush() in Arduino）Python 和 Arduino 之间的新数据.此外，Python 和 Arduino 代码中的一个小延迟是必要的，以使其工作。
Pyhton
import os
import time
import serial
# Name of csv file with drawing coordinates
fileName = "coordinates.csv"
# Create serial connection
ser = serial.Serial(port='/dev/tty.usbserial-A9005bDh', baudrate=9600)
wd = os.getcwd()
myFile = open(wd + "/graphics/" + fileName)
#num_lines = sum(1 for line in myFile)
state = '0'
idx = 0
while True: # Exits when there is no more lines to read
#print "state", state
while state == '0': # Wait for Arduino to be ready
ser.flushInput() # Clear input buffer
state = str(ser.read())
if state == '1': # Send one more line to Arduino
line = myFile.readline()
if not line:
break
print "Coordinate", idx
print line
ser.flushOutput() # Clear output buffer
ser.write(line)
time.sleep(0.1)
idx = idx + 1
state = '0' # Set waiting flag – make Arduino wait for next line
ser.close()
myFile.close
Arduino serialEvent 函数
void serialEvent() {
if ((stepper1.distanceToGo() == 0) && (stepper2.distanceToGo() == 0)) {
Serial.write('1'); // Tell Python that Arduino is ready for one more line
delay(10);
Serial.flush(); // clear buffer
}
while (Serial.available() && coord_complete == false) {
char ch = Serial.read(); // Get new character
Serial.flush();
// If digit; add it to coord_string
if (isDigit(ch)) {
coord_string[index++] = ch;
// Else if ch is ","; then rename to x_new
} else if (ch == ',') {
coord_string[index++] = NULL; // Finish coord_string
x_new = atoi(coord_string); // Convert to integer
x_complete = true; // Change x_complete to true
index = 0; // Reset index
memset(coord_string, 0, sizeof(coord_string)); // Reset coord_string
// Else if ch is a new line; then rename as y_new
} else if (ch == ';') {
//Serial.write('0');
coord_string[index++] = NULL;
y_new = atoi(coord_string);
y_complete = true;
index = 0;
memset(coord_string, 0, sizeof(coord_string));
}
// Ends while-loop when true
coord_complete = x_complete * y_complete;
}
}