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                  = 'I' -write only  -Pin State: 0,1
#	Outputs                 = 'O' -read only   -Pin State: 0,1
#	PWM Outputs             = 'P' -read only   -Pin State: 0-255
#	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'


# Set how many Inputs you have programmed in Arduino and which pins are Inputs
Inputs = 17
InPinmap = [32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48]

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

# Set how many PWM Outputs you have programmed in Arduino and which pins are PWM Outputs
PwmOutputs = 2
PwmOutPinmap = [12,11]

# Set how many Analog Inputs you have programmed in Arduino and which pins are Analog Inputs
AInputs = 1
AInPinmap = [79]


# Set how many Latching Analog Inputs you have programmed in Arduino and how many latches there are
LPoti = 2
LPotiLatches = [9,4]

# 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)
AbsKnob = 1
AbsKnobPos = 30


########  End of Config!  ########

######## SetUp of HalPins ########

# setup Input halpins
for port in range(Inputs):
    c.newpin("dIn-%02d" % InPinmap[port], hal.HAL_BIT, hal.HAL_IN)
    c.newparam("dIn-%02d-invert" % InPinmap[port], hal.HAL_BIT, hal.HAL_RW)

# setup Output halpins
for port in range(Outputs):
    c.newpin("dOut-%02d" % OutPinmap[port], hal.HAL_BIT, hal.HAL_OUT)

# setup Pwm Output halpins
for port in range(PwmOutputs):
    c.newpin("PwmOut-%02d" % PwmOutPinmap[port], hal.HAL_FLOAT, hal.HAL_OUT)

# setup Analog Input halpins
for port in range(AInputs):
    c.newpin("aIn-%02d" % AInPinmap[port], hal.HAL_FLOAT, hal.HAL_IN)

# setup Latching Poti halpins
for latches in range(LPoti):
	for port in range(LPotiLatches[latches]):
		c.newpin("LPoti-%02d" % [port], hal.HAL_BIT, hal.HAL_IN)

# setup Absolute Encoder Knob halpins
if AbsKnob:
	for port in range(AbsKnobPos):
		c.newpin("AbsKnobPos-%02d" % [port], hal.HAL_BIT, hal.HAL_IN)

c.ready()

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

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) 



######## Detect Serial connection and blink Status LED if connection lost -todo ########
#try:

arduino = serial.Serial(connection, 9600, timeout=1, xonxoff=False, rtscts=False, dsrdtr=True)


while True:
	try:	
		data = arduino.readline().decode('utf-8')
		# I127:1

		data = data.split(":",1)
		#[I127]["1"]
		
		
		if len(data) == 2:
			cmd = data[0][0]
			io = extract_nbr(data[0])
			value = extract_nbr(data[1])
			data[1] = extract_nbr(data[1])
			if data[1]<0: data[1] = 0

			if data[0] == "I":
				c.dIn = data[1]
			elif data[0] == "A":
				c.aIn = data[1]
			elif data[0] == "L":
				for port in range(LPotiLatches[latches]):
					if ("LPoti-%02d %" [port]) == data[1]:
					c.LPotiKnob = data[1]

			elif data[0] == "K":
				c.AbsKnob = data[1]
			else: pass

	finally:
		pass