def __select_port(self, n):
""" selects a port.
Using an int in [0-7], activte the chip select for
device n.
Args:
n (int): the port corresponding to the device to activate.
"""
# convert int to its binary representation.
msb, mb, lsb = cream.num2bin(n)
# set GPIOs to output bit pattern.
GPIO.output(self._PORTS['msb'], msb)
GPIO.output(self._PORTS['mb'], mb)
GPIO.output(self._PORTS['lsb'], lsb)
#Test SPI transactions
spi = spidev.SpiDev()
spi.open(0,0)
def readADC(nADC):
if (nADC > 7) or (nADC < 0):
return -1
r = spi.xfer2([1, (8+nADC)<<4, 0])
out = ((r[1]&3) << 8) + r[2]
return out
k = 0
while True:
msb, mb, lsb = cream.num2bin(k)
GPIO.output(A, lsb)
GPIO.output(B, mb)
GPIO.output(C, msb)
D = [0, 0]
for n in xrange(0, 2):
D[n] = readADC(n)
print "\tUP: " + str(D[0]) + "\tRIGHT: " + str(D[1])
time.sleep(0.5)
print str(k)
k = k + 1
if k == 8:
k = 0