def test_gpio_values(self):
"""Simple test to demonstrate bit-banging.
"""
if self.skip_loopback:
raise SkipTest('Skip loopback test on multiport device')
direction = 0xFF & ~((1 << 4) - 1) # 4 Out, 4 In
gpio = GpioSyncController()
gpio.configure(self.url, direction=direction, initial=0xee)
outs = bytes([(out & 0xf) << 4 for out in range(1000)])
ins = gpio.exchange(outs)
exp_in_count = min(len(outs), gpio.ftdi.fifo_sizes[0])
self.assertEqual(len(ins), exp_in_count)
last = None
for sout, sin in zip(outs, ins):
if last is not None:
# output nibble
sin_out = sin >> 4
# input nibble
sin_in = sin & 0xF
# check inputs match last output
self.assertEqual(sin_out, last)
# check level of output match the last written
self.assertEqual(sin_in, last)
# an IN sample if captured on the next clock of the OUT sample
# keep the MSB nibble, i.e. the nibble configured as output
last = sout >> 4
gpio.close()
def transmitSync(self): gpio = GpioSyncController() gpio.configure(self.device, direction=self.direction, frequency=self.frequency) # txBytes = bytearray() # for byte in self.txList: # txBytes.append(byte) # print(txBytes) rxBytes = gpio.exchange( self.txList ); # print(rxBytes) gpio.close() self.rxList = [] for byte in rxBytes: self.rxList.append(byte)
def test_gpio_baudate(self):
# this test requires an external device (logic analyser or scope) to
# check the bitbang read and bitbang write signal (BB_RD, BB_WR) and
# mesure their frequency. The EEPROM should be configured to enable
# those signal on some of the CBUS pins, for example.
gpio = GpioSyncController()
direction = 0xFF & ~((1 << 4) - 1) # 4 Out, 4 In
gpio.configure(self.url, direction=direction)
buf = bytes([0xf0, 0x00] * 64)
freqs = [50e3, 200e3, 1e6, 3e6]
if gpio.ftdi.is_H_series:
freqs.extend([6e6, 10e6, 12e6])
for freq in freqs:
# set the bitbang refresh rate
gpio.set_frequency(freq)
self.assertEqual(gpio.frequency, freq)
# be sure to leave enough time to purge buffers (HW FIFO) or
# the frequency changes occur on the current buffer...
gpio.exchange(buf)
sleep(0.01)
gpio.close()
def transmitSync(self, frequency): gpio = GpioSyncController() gpio.configure(self.device, self.directionArray[0], frequency=frequency) self.rxArray = gpio.exchange( self.txArray ); gpio.close()
args = parser.parse_args()
url = "ftdi://ftdi:{}:{}/{}".format(args.type, args.serial[0], args.instance)
gpio = GpioSyncController()
gpio.configure(url, direction=0b1111_1111)
gpio.set_frequency(200)
def signal_handler(sig, frame):
print('You pressed Ctrl+C!')
disable(gpio)
sys.exit(0)
signal.signal(signal.SIGINT, signal_handler)
enable(gpio)
if "load" in args:
with open(args.load[0], "rb") as fh:
data = fh.read(1)
while data:
data_value = int.from_bytes(data, byteorder='big', signed=False)
write_byte(gpio, data_value)
data = fh.read(1)
disable(gpio)
gpio.close()