我一直在研究这段代码，用Python控制Arduino上的大量伺服器。 代码有效，但我看到了一些与时间有关的奇怪行为。 在每次更新伺服器之间，我需要一个睡眠命令。 如果我不插入睡眠，程序将在我第一次运行时运行，但如果Python代码被停止，那么我尝试再次通过串口连接Python，Arduino没有响应。 什么可能发生在串口上，我怎么能防止这种情况发生？
另外，我是否使用memcpy以最有效的方式解析进入Arduino的数据？或者有更好或更标准的方法吗？
我读过有关使用serialEvent的信息，在这种情况下使用该命令解析串行数据是否有好处？
//ARDUINO CODE
#include <Servo.h>
int servoPins[] = {9, 10};
//int servoPins[] = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38};
//int servoPins[] = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34};
const int numServos = sizeof(servoPins)/sizeof(int);
Servo servos[numServos];
char serialData[numServos * 3];
char tempData[3];
void setup() {
Serial.begin(9600);
Serial.println("Ready");
for (int i=0; i < numServos; i++) {
servos[i].attach(servoPins[i]);
//servos[i].write(20);
}
}
void loop() {
if (Serial.available()) {
Serial.readBytesUntil('\0', serialData, numServos * 3);
for (int i=0; i < numServos; i++) {
memmove(tempData, serialData + i * 3, 3);
servos[i].write(atoi(tempData));
}
}
}
#PYTHON CODE
""" Control n servos on n arduinos over serial
"""
import glob
import platform
import serial
from time import sleep
import sys
'''
Servo
Id number, angle for servo, Arduino port servo is on
For now the port is used as an index, so please number them going from 0-n
'''
class Servo:
id_num = 0
angle = 0
port = 0
def __init__(self, id_num, angle, port):
self.id_num = id_num
self.angle = angle
self.port = port
'''
ServoDriver
-Stores a list of servos
-Open ports to Arduinos
-Stores a list of those ports
-Creates a map of which servos are on which ports
-Provides a way to update the angle of all servos on all ports
'''
class ServoDriver:
def __init__(self, servos):
self.ports = self.open_ports()
self.servos = servos
# looks for all devices that have the same name pattern as an Arduino and opens them
def open_ports(self):
# find arduinos
# note: currently this is Mac only
devices = glob.glob('/dev/tty.usbmodem*')
print devices
if len(devices) == 0:
print "No Arduinos found"
sys.ext(1)
ports = []
for device in devices:
try:
# connect to serial port
ports.append(serial.Serial(device, 9600))
except:
print 'Failed to open port'
sys.ext(1)
# need a short delay right after serial port is started for the Arduino to initialize
sleep(2)
return ports
# update the angle of all servos on all ports
def update(self, servos):
debug = True
servo_data = []
for p in self.ports:
servo_data.append('')
for servo_update in servos:
for servo_stored in self.servos:
if servo_stored.id_num == servo_update.id_num:
this_port = servo_stored.port
break
# constrain servo angles to avoid damaging servos
if servo_update.angle > 135:
servo_update.angle = 135
else if servo_update.angle < 45:
servo_update.angle = 45
# append angle to the datum for this port
servo_data[this_port] = servo_data[this_port] + str(servo_update.angle).zfill(3)
for servo_datum in servo_data:
# append null byte for arduino to recognize end of data
servo_datum = servo_datum + "\0"
# send data to the Arduinos
for port,servo_datum in zip(self.ports,servo_data):
port.write(servo_datum)
def close_ports(self):
print 'closing ports'
for port in self.ports:
port.close()
# generates values for making a servo sweep back and forth
def servo_iter():
l = []
#for i in range(0,1):
l.append(40)
#for i in range(0,1):
l.append(80)
for pos in l:
yield pos
def servo_iter_2(total):
for i in range(0,total):
yield i
if __name__ == "__main__":
# create a list of servos with mappings to ports
# if you have the wrong number of servos it acts weird
#num_servos = 32
num_servos = 2
servos = []
servos.append(Servo(0, 40, 0))
servos.append(Servo(1, 40, 0))
'''
servos.append(Servo(2, 40, 0))
servos.append(Servo(3, 40, 0))
servos.append(Servo(4, 40, 0))
servos.append(Servo(5, 40, 0))
servos.append(Servo(6, 40, 0))
servos.append(Servo(7, 40, 0))
servos.append(Servo(8, 40, 0))
servos.append(Servo(9, 40, 0))
servos.append(Servo(10, 40, 0))
servos.append(Servo(11, 40, 0))
servos.append(Servo(12, 40, 0))
servos.append(Servo(13, 40, 0))
servos.append(Servo(14, 40, 0))
servos.append(Servo(15, 40, 0))
servos.append(Servo(16, 40, 0))
servos.append(Servo(17, 40, 0))
servos.append(Servo(18, 40, 0))
servos.append(Servo(19, 40, 0))
servos.append(Servo(20, 40, 0))
servos.append(Servo(21, 40, 0))
servos.append(Servo(22, 40, 0))
servos.append(Servo(23, 40, 0))
servos.append(Servo(24, 40, 0))
servos.append(Servo(25, 40, 0))
servos.append(Servo(26, 40, 0))
servos.append(Servo(27, 40, 0))
servos.append(Servo(28, 40, 0))
servos.append(Servo(29, 40, 0))
servos.append(Servo(30, 40, 0))
servos.append(Servo(31, 40, 0))
servos.append(Servo(32, 40, 0))
'''
#if len(servos) != num_servos:
# print 'wrong number of servos'
# sys.ext(1)
# comment out the next two lines if you only have 1 arduino
#servos.append(Servo(2, 40, 1))
#servos.append(Servo(3, 40, 1))
#servos.append(Servo(4, 40, 2))
#servos.append(Servo(5, 40, 2))
angles = []
for i in range(0,len(servos)):
angles.append(40)
try:
# instantiate a driver
# must happen inside try-finally
driver = ServoDriver(servos)
iter1 = False
if iter1:
pos = servo_iter()
else:
pos = servo_iter_2(len(servos))
while True:
try:
x = pos.next()
except StopIteration:
if iter1:
pos = servo_iter()
else:
pos = servo_iter_2(len(servos))
x = pos.next()
# create a list of servos with ids and angles to update positions of servos
if iter1:
for servo in servos:
servo.angle = x
else:
for i,servo in zip(angles,servos):
servo.angle = i
# call the driver with the list of servos
driver.update(servos)
sleep(0.5)
for i in range(0, len(servos)):
if i == x:
angles[i] = 80
else:
angles[i] = 40
# close the serial port on exit, or you will have to unplug the arduinos to connect again
finally:
driver.close_ports()
我认为这里正确的答案是给Arduino增加延迟。
答案 0 :(得分：3)
每次通过usb进行串行连接时，Arduino都会重置。如果您想暂时禁用，可以在地和复位之间插入一个10微法的电容。这将使其免于自动重置，并且可以轻松删除以进行程序上传。