#!/usr/bin/env python
# coding: utf-8
# copyright Michael Weber 2008 avr at xmw.de
# released with GNU GPL
# build upon the docs at http://www.myavr.de/download/techb_mysmartusb.pdf
# tested with mySmartUSB hardware version 2 firmware 2.5

import sys, tty
import serial, os, os.path

CP2101_DEVICES = filter(lambda fn: fn.startswith('ttyUSB'),
    os.listdir('/sys/bus/usb-serial/drivers/cp210x/'))
if len(CP2101_DEVICES) > 1:
    CP2101_DEVICES.sort()
    print "interface auto detection got devices", CP2101_DEVICES
    print "using", CP2101_DEVICES[0]
LINKNAME = os.path.join('/dev', CP2101_DEVICES[0])

class mySmartUsb:
    MAGIC = ''.join(map(chr, (0xE6, 0xB5, 0xBA, 0xB9, 0xB2, 0xB3, 0xA9)))

    def __init__(self, linkname):
	self.link = serial.serial(linkname, tty.B19200)

    def write(self, cmd):
	"""write MAGIC with given cmd to the unit"""
	self.link.write(self.MAGIC + cmd)

    def read(self):
	"""read up to 100 bytes from the unit, timeout 10ms"""
	return self.link.read(100, timeout=0.01)

    def action(self, cmd):
	"""combined write and read action"""
	self.write(cmd)
	return self.read()

    def resetBoard(self):
	"""reset the board"""
	return self.action('r')

    def resetProgrammer(self):
	"""reset the programmer"""
	return self.action('R')

    def setBoardPowerOn(self):
	"""set board power to on"""
	return self.action('+')

    def setBoardPowerOff(self):
	"""set board power to off"""
	return self.action('-')

    def setModeProgram(self):
	"""set mode to program"""
	return self.action('p')

    def setModeData(self):
	"""set mode to data"""
	return self.action('d')

    def setModeQuiet(self):
	"""set mode to quiet"""
	return self.action('q')

    def getStatus(self):
	"""get the programmer status"""
	return self.action('i')

if __name__ == '__main__':
    import sys, os.path

    modes = []
    modes.append(('-mp', mySmartUsb.setModeProgram))
    modes.append(('-md', mySmartUsb.setModeData))
    modes.append(('-mq', mySmartUsb.setModeQuiet))
    modes.append(('-pon', mySmartUsb.setBoardPowerOn))
    modes.append(('-poff', mySmartUsb.setBoardPowerOff))
    modes.append(('-r', mySmartUsb.resetBoard))
    modes.append(('-R', mySmartUsb.resetProgrammer))
    modes.append(('-i', mySmartUsb.getStatus))

    def usage():
	#print 'usage:', sys.argv[0], '<serial port>', '<option>\n'
    	print 'usage:', os.path.split(sys.argv[0])[1], '<option>\n'
    	print '\twith <option> in:'
    	for (arg, func) in modes:
    	    print '\t%s\t%s' % (arg, func.__doc__)
	#print '\nexample for board reset: %s /dev/ttyUSB0 -r' % sys.argv[0]
	print '\nexample for board reset: %s -r' % sys.argv[0]

    #if len(sys.argv) != 3 or not os.path.exists(sys.argv[1]) \
    #    or len(filter(lambda s: s[0] == sys.argv[2], modes)) != 1:
    if len(sys.argv) != 2 \
	or len(filter(lambda s: s[0] == sys.argv[1], modes)) != 1:
	usage()
	sys.exit(not None)

    m = mySmartUsb(LINKNAME)
    #print filter(lambda s: s[0] == sys.argv[2], modes)[0][1](m)
    print filter(lambda s: s[0] == sys.argv[1], modes)[0][1](m)