如何使用pyfirmata、python和Arduino同时移动两个伺服

Question

我正在尝试对机械臂进行编程，我需要两个伺服机构同时运行，并且能够在不同的方向上运行，例如在90°到180°以及另一个伺服机构90°到0°时，我正在使用Arduino、python和pyfirmata。任何帮助都将非常感谢！

import pyfirmata
import time
board = pyfirmata.Arduino('/dev/cu.usbmodem14201')
armlower2 = board.get_pin('d:6:s')
armlower1 = board.get_pin('d:10:s')
for angle in range(90, 180, 1):
armlower2.write(angle)
time.sleep(0.015)
for angle in range(180, 90, -1):
armlower2.write(angle)
time.sleep(0.015)
for angle in range(90, 0, -1):
armlower1.write(angle)
time.sleep(0.015)
for angle in range(0, 90, 1):
armlower1.write(angle)
time.sleep(0.015)

这会移动伺服系统，但一次只能移动一个？

Answer 1

最简单的方法是使用threading，这里有一个非常简单的例子：

import threading
def move_armlower2(): 
for angle in range(90, 180, 1):
armlower2.write(angle)
time.sleep(0.015)
for angle in range(180, 90, -1):
armlower2.write(angle)
time.sleep(0.015)
def move_armlower1():
for angle in range(90, 0, -1):
armlower1.write(angle)
time.sleep(0.015)
for angle in range(0, 90, 1):
armlower1.write(angle)
time.sleep(0.015)
threads = [
threading.Thread(target=move_armlower2), # Creating threads
threading.Thread(target=move_armlower1) 
]
for th in threads:
th.start() # Starts the thread
for th in threads:
th.join() # Waits for the thread to terminate

参考文献：

• threading.Thread
• Thread.start
• Thread.join

Answer 2

您应该围绕"；当前值"；以及"；期望值"；，即，你想要的值与你当前所处的值(角度(。这可以扩展到任何数量的电机，使用电机阵列，并在循环中遍历它们的值。但对于两个，您可以简单地执行以下操作。

// The angle values you want to achieve, and what they currently are
GLOBAL want1, want2
GLOBAL current1, current2
LOOP {
LOCAL updelta = 1
LOCAL downdelta = -1
if want1 > current1
movearm1(updelta)
current1 = current1 + updelta
else if want1 < current1
movearm1(downdelta)
current1 = current1 + downdelta
if want2 > current2
movearm2(updelta)
current2 = current2 + updelta
else if want2 < current2
movearm2(downdelta)
current2 = current2 + downdelta
sleep(0.015)
}