LinuxCNC_ArduinoConnector/arduino.py

#!/usr/bin/python3.9
import serial, time, hal
#	LinuxCNC_ArduinoConnector
#	By Alexander Richter, info@theartoftinkering.com 2022

#	This Software is used as IO Expansion for LinuxCNC. Here i am using a Mega 2560.

#	It is NOT intended for timing and security relevant IO's. Don't use it for Emergency Stops or Endstop switches!

#	You can create as many digital & analog Inputs, Outputs and PWM Outputs as your Arduino can handle.
#	You can also generate "virtual Pins" by using latching Potentiometers, which are connected to one analog Pin, but are read in Hal as individual Pins.

#	Currently the Software provides: 
#	- analog Inputs
#	- latching Potentiometers
#	- 1 absolute encoder input
#	- digital Inputs
#	- digital Outputs

#	The Send and receive Protocol is <Signal><PinNumber>:<Pin State>
#	To begin Transmitting Ready is send out and expects to receive E: to establish connection. Afterwards Data is exchanged.
#	Data is only send everythime it changes once.

#	Inputs & Toggle Inputs  = 'I' -write only  -Pin State: 0,1
#	Outputs                 = 'O' -read only   -Pin State: 0,1
#	PWM Outputs             = 'P' -read only   -Pin State: 0-255
#   Digital LED Outputs     = 'D' -read only   -Pin State: 0,1
#	Analog Inputs           = 'A' -write only  -Pin State: 0-1024
#	Latching Potentiometers = 'L' -write only  -Pin State: 0-max Position
#	Absolute Encoder input  = 'K' -write only  -Pin State: 0-32


#	Command 'E0:0' is used for connectivity checks and is send every 5 seconds as keep alive signal

#	This program is free software; you can redistribute it and/or modify
#	it under the terms of the GNU General Public License as published by
#	the Free Software Foundation; either version 2 of the License, or
#	(at your option) any later version.
#	This program is distributed in the hope that it will be useful,
#	but WITHOUT ANY WARRANTY; without even the implied warranty of
#	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#	See the GNU General Public License for more details.
#	You should have received a copy of the GNU General Public License
#	along with this program; if not, write to the Free Software
#	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


c = hal.component("arduino") 	#name that we will cal pins from in hal
connection = '/dev/ttyACM0' 	#this is the port your Arduino is connected to. You can check with ""sudo dmesg | grep tty"" in Terminal


# Set how many Inputs you have programmed in Arduino and which pins are Inputs, Set Inputs = 0 to disable
Inputs = 5
InPinmap = [37,38,39,40,41]

# Set how many Toggled ("sticky") Inputs you have programmed in Arduino and which pins are Toggled Inputs , Set SInputs = 0 to disable
SInputs = 5
sInPinmap = [32,33,34,35,36]


# Set how many Outputs you have programmed in Arduino and which pins are Outputs, Set Outputs = 0 to disable
Outputs = 9				#9 Outputs, Set Outputs = 0 to disable
OutPinmap = [10,9,8,7,6,5,4,3,2,21]	

# Set how many PWM Outputs you have programmed in Arduino and which pins are PWM Outputs, you can set as many as your Arduino has PWM pins. List the connected pins below.
PwmOutputs = 2			#number of PwmOutputs, Set PwmOutputs = 0 to disable 
PwmOutPinmap = [11,12]	#PwmPutput connected to Pin 11 & 12

# Set how many Analog Inputs you have programmed in Arduino and which pins are Analog Inputs, you can set as many as your Arduino has Analog pins. List the connected pins below.
AInputs = 1				#number of AInputs, Set AInputs = 0 to disable 
AInPinmap = [1]			#Potentiometer connected to Pin 1 (A0)


# Set how many Latching Analog Inputs you have programmed in Arduino and how many latches there are, you can set as many as your Arduino has Analog pins. List the connected pins below.
LPoti = 2				#number of LPotis, Set LPoti = 0 to disable 
LPotiLatches = [[2,9],	#Poti is connected to Pin 2 (A1) and has 9 positions
				[3,4]]	#Poti is connected to Pin 3 (A2) and has 4 positions

# Set if you have an Absolute Encoder Knob and how many positions it has (only one supported, as i don't think they are very common and propably nobody uses these anyway)
# Set AbsKnob = 0 to disable
AbsKnob = 0 	#1 enable
AbsKnobPos = 32

# Set how many Digital LED's you have connected. 
DLEDcount = 8


Debug = 0		#only works when this script is run from halrun in Terminal. "halrun","loadusr arduino" now Debug info will be displayed.
########  End of Config!  ########
olddOutStates= [0]*Outputs
oldPwmOutStates=[0]*PwmOutputs

# Inputs and Toggled Inputs are handled the same. 
# For DAU compatiblity we set them up seperately. 
# Here we merge the arrays.

Inputs = Inputs+ SInputs
InPinmap += sInPinmap
######## SetUp of HalPins ########

# setup Input halpins
for port in range(Inputs):
    c.newpin("dIn.{}".format(InPinmap[port]), hal.HAL_BIT, hal.HAL_OUT)
    c.newparam("dIn.{}-invert".format(InPinmap[port]), hal.HAL_BIT, hal.HAL_RW)

# setup Output halpins
for port in range(Outputs):
    c.newpin("dOut.{}".format(OutPinmap[port]), hal.HAL_BIT, hal.HAL_IN)
    olddOutStates[port] = 0

# setup Pwm Output halpins
for port in range(PwmOutputs):
    c.newpin("PwmOut.{}".format(PwmOutPinmap[port]), hal.HAL_FLOAT, hal.HAL_IN)
    oldPwmOutStates[port] = 255
# setup Analog Input halpins
for port in range(AInputs):
    c.newpin("aIn.{}".format(AInPinmap[port]), hal.HAL_FLOAT, hal.HAL_OUT)

# setup Latching Poti halpins
for Poti in range(LPoti):
	for Pin in range(LPotiLatches[Poti][1]):
		c.newpin("LPoti.{}.{}" .format(LPotiLatches[Poti][0],Pin), hal.HAL_BIT, hal.HAL_OUT)

# setup Absolute Encoder Knob halpins
if AbsKnob:
	for port in range(AbsKnobPos):
		c.newpin("AbsKnob.{}".format(port), hal.HAL_BIT, hal.HAL_OUT)

# setup Digital LED halpins
if DLEDcount > 0:
	for port in range(DLEDcount):
		c.newpin("DLED.{}".format(port), hal.HAL_BIT, hal.HAL_IN)

c.ready()

#setup Serial connection
arduino = serial.Serial(connection, 115200, timeout=1, xonxoff=False, rtscts=False, dsrdtr=True)
######## GlobalVariables ########
firstcom = 0
event = time.time()
timeout = 9 #send something after max 9 seconds


######## Functions ########

def keepAlive(event):
    return event + timeout < time.time()

def readinput(input_str):
	for i in range(50):

		if input_str:
			string = input_str.decode()  # convert the byte string to a unicode string
			print (string)
			num = int(string) # convert the unicode string to an int
	return num


def extract_nbr(input_str):
    if input_str is None or input_str == '':
        return 0

    out_number = ''
    for ele in input_str:
        if ele.isdigit():
            out_number += ele
    return int(out_number) 

def managageOutputs():
	for port in range(PwmOutputs):
		State = int(c["PwmOut.{}".format(PwmOutPinmap[port])])
		if oldPwmOutStates[port] != State: 	#check if states have changed
			Sig = 'P'
			Pin = int(PwmOutPinmap[port])
			command = "{}{}:{}\n".format(Sig,Pin,State)
			arduino.write(command.encode())
			if (Debug):print ("Sending:{}".format(command.encode()))
			oldPwmOutStates[port]= State

	for port in range(Outputs):
		State = int(c["dOut.{}".format(OutPinmap[port])])
		if olddOutStates[port] != State:	#check if states have changed
			Sig = 'O'
			Pin = int(OutPinmap[port])
			command = "{}{}:{}\n".format(Sig,Pin,State)
			arduino.write(command.encode())
			if (Debug):print ("Sending:{}".format(command.encode()))
			olddOutStates[port]= State
		
	for port in range(DLEDcount):
		State = int(c["DLED.{}".format(port)])
		Sig = 'D'
		Pin = int(port)
		command = "{}{}:{}\n".format(Sig,Pin,State)
		arduino.write(command.encode())
		if (Debug):print ("Sending:{}".format(command.encode()))


while True:
	
	try:
		data = arduino.readline().decode('utf-8')					#read Data received from Arduino and decode it
		if (Debug):print ("I received:{}".format(data))
		data = data.split(":",1)

		try:
			cmd = data[0][0]
			if cmd == "":
				if (Debug):print ("No Command!:{}.".format(cmd))
			
			else:
				if not data[0][1]:
					io = 0
				else:
					io = extract_nbr(data[0])
				value = extract_nbr(data[1])
				if value<0: value = 0
				

				if cmd == "I":
					firstcom = 1
					if value == 1:
						c["dIn.{}".format(io)] = 1
						c["dIn.{}-invert".format(io)] = 0
						if(Debug):print("dIn{}:{}".format(io,1))
						
					if value == 0:
						c["dIn.{}".format(io)] = 0
						c["dIn.{}-invert".format(io)] = 1
						if(Debug):print("dIn{}:{}".format(io,0))
					else:pass

				elif cmd == "A":
					firstcom = 1
					c["aIn.{}".format(io)] = value
					if (Debug):print("aIn.{}:{}".format(io,value))

				elif cmd == "L":
					firstcom = 1

					for Poti in range(LPoti):
						if LPotiLatches[Poti][0] == io:
							for Pin in range(LPotiLatches[Poti][1]):
								if Pin == value:
									c["LPoti.{}.{}" .format(io,Pin)] = 1
									if(Debug):print("LPoti.{}.{} =1".format(io,Pin))
								else:
									c["LPoti.{}.{}" .format(io,Pin)] = 0
									if(Debug):print("LPoti.{}.{} =0".format(io,Pin))	

				elif cmd == "K":
					firstcom = 1
					for port in range(AbsKnobPos):
						if port == value:
							c["AbsKnob.{}".format(port)] = 1
							if(Debug):print("AbsKnob.{}:{}".format(port,1))
						else:
							c["AbsKnob.{}".format(port)] = 0
							if(Debug):print("AbsKnob.{}:{}".format(port,0))
					
				elif cmd == 'E':
					arduino.write(b"E0:0\n")
					if (Debug):print("Sending E0:0 to establish contact")
				else: pass
	

		except: pass
	

	except KeyboardInterrupt:
		if (Debug):print ("Keyboard Interrupted.. BYE")
		exit()
	except: 
		if (Debug):print ("I received garbage")
		arduino.flush()
	
	if firstcom == 1: managageOutputs()		#if ==1: E0:0 has been exchanged, which means Arduino knows that LinuxCNC is running and starts sending and receiving Data

	if keepAlive(event):	#keep com alive. This is send to help Arduino detect connection loss.
		arduino.write(b"E:\n")
		if (Debug):print("keepAlive")
		event = time.time()