Operate a Coin Acceptor

The initialization sequence as defined per the MDB Specification is as follows:

M,1 R,08 R,09 R,0F,00 R,0F,0100000000 R,0A R,0C,000F0000 (Poll, in loop)

Now, below, there is a python program that does this sequence programatically.

Some remarks:

This program follows the advised sequence described in Section 5 of the MDB Specification to Initialize a Coin Acceptor.
The Tube status is always empty
The program is doing nothing with Coin Inserted events
The VMC is not enabling any of the Expansion Features that are allowed for level 3 Coin Acceptors.
If the coin acceptor sends an incorrect message, the sequence is not reinitialized (this is something that must be done if the program is to be used in a real VMC)
Code is not optimized (e.g. Readline must be called after write2Serial, so this could be put in a function)
The goal of this example is to demonstrate and keep it simple, this is not suitable for "Real" VMCs. However, it can serve as a starting point.

from os import read, write import serial,sys,time #Commands that need to be sent to the interface # M,1 -> Activate Master # R,08 -> Reset Coin Changer # R,0B -> Obtain Just Reset from Changer~ # R,09 # R,0F,00 -> Request additional Features (LVL 3+ Only) # R,0F,01ZZZZZZZZ -> To enable desired features (depends on the changer's reply to previous command) (LVL 3+ Only) # R,0A -> Tube Status # R,0C,000F0000 # No manual Dispense (Last 2 Bytes), Coin Types 1,2,3 and 4 are accepted (000F , on first 2 bytes) # R,0B -> Poll (In Loop) # COMMAND DEFINITION ENABLE_MASTER="M,1" RESET_COIN_ACCEPTOR="R,08" REQUEST_SETUP_INFO="R,09" EXPANSION_REQUEST="R,0F,00" EXPANSION_FEATURE_ENABLE="R,0F,0100000000" TUBE_STATUS_REQUEST="R,0A" COIN_TYPE="R,0C,000F0000" POLL="R,0B" ########################################### #CHANGER RESPONSE TABLE def initSerialPort(portName): global ser ser = serial.Serial() #Create Serial Object ser.baudrate = 115200 #Set the appropriate BaudRate ser.timeout = 1 #The maximum timeout that the program waits for a reply. If 0 is used, the pot is blocked until readline returns ser.port = portName # Specify the device file descriptor ser.open() #Open the serial connection def readSerial(): global ser s = ser.readline().decode('ascii') # Read the response # DEBUG : print("Read from Serial port: " + s) return s def write2Serial(message): global ser buff = message + "\n" ser.write(bytes(buff,'ascii')) #Write the version command "V\n" encoded in Binary def initCoinAcceptor(): write2Serial(ENABLE_MASTER) readSerial() write2Serial(RESET_COIN_ACCEPTOR) readSerial() write2Serial(REQUEST_SETUP_INFO) setupInfo = readSerial() print("Changer Setup Info:" + setupInfo) write2Serial(EXPANSION_REQUEST) expansion = readSerial() print("Changer Expansion Response:" + expansion) write2Serial(TUBE_STATUS_REQUEST) readSerial() write2Serial(COIN_TYPE) readSerial() def startPollLoop(): while True: write2Serial(POLL) # Poll Coin Changer print("Changer Response:" + readSerial()) time.sleep(0.5) if __name__ == "__main__": print("Qiba Simple python example to operate a coin acceptor\n\n") if len(sys.argv) != 2: print("Usage: python VMCCoinAcceptor.py <port_name>") exit(1) portName = sys.argv[1] initSerialPort(portName) write2Serial("V") print("Device Firmware version:" + readSerial() + "\n") initCoinAcceptor() startPollLoop()

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