def sendpacket( data ):
pkt = mkpkt( data )
while True:
com.write( pkt )
if waitack():
break
else:
print "CRC NACK. RESENDING."
def upload( data ):
data = hpstr.toarr( data )
resp = com.read( 1 )[0]
if resp != ord( 'D' ):
cancel()
print "Device didn't accept file:", hex( resp )
return False
pos = 0
pktnr = 1
while pos < len( data ):
sleep(0.1)
size = len( data ) # len data may change due to padding
if size-pos >= 1024:
ptype = 2
plen = 1024
if size-pos >= 128:
ptype = 1
plen = 128
else:
while size-pos < 128:
data.append( 0x1a )
size += 1
ptype = 1
plen = 128
chunk = data[pos:pos+plen]
if ptype == 1: #SOH
com.write( [1] )
#print "SOH",
sleep( 0.1 )
com.write( [pktnr, 255-pktnr] )
#print hpstr.tohexstr( [pktnr, 255-pktnr] ),
com.write( chunk )
#print hpstr.tohexstr( chunk ),
crc = hpcrc( chunk )
com.write( [crc>>8, crc & 0xff ] )
if waitack() == True:
#print "CHKSUM ACK"
pos += plen
else:
print "CHKSUM NACK"
# TODO: retry counter
# TODO: cancel checking
com.write( [4] ) #EOT
#print "EOT"
#waitack()
#sendack()
return waitack()
def cmd( cmd, args=None ):
if args:
s = cmd + mkpacket( args )
#print "CMD:", hpstr.tohexstr( s )
# TODO: can we send as one chunk?
com.write( s[0] )
sleep( 0.1 )
com.write( s[1:] )
else:
s = cmd
#print "CMD:", hpstr.tohexstr( s )
com.write( s )
def cancel():
com.write( '\x18' )
com.write( '\x18' )
com.write( '\x18' )
def sendnack():
com.write( '\x15' )
def sendack():
com.write( '\x06' )
def write(data, timeout=1000):
"""Writes data to USB.
Returns number of bytes written.
"""
return com.write(data, timeout=timeout)