本文整理汇总了Python中spidev.SpiDev.writebytes方法的典型用法代码示例。如果您正苦于以下问题：Python SpiDev.writebytes方法的具体用法？Python SpiDev.writebytes怎么用？Python SpiDev.writebytes使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类spidev.SpiDev的用法示例。
在下文中一共展示了SpiDev.writebytes方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: dac8568
# 需要导入模块: from spidev import SpiDev [as 别名]
# 或者: from spidev.SpiDev import writebytes [as 别名]
class dac8568():
def __init__(self, dev):
self.dev = SpiDev()
try:
self.dev.open(4,dev)
except IOError as e:
print("Error opening /dev/spidev4.%d: %s" % (dev, e))
raise
def build_command(self, control, addr, data):
prefix = 0
features = 0
cmd = [0,0,0,0]
cmd[3] = (0xf & features) << 0 | (0xf & data) << 4
cmd[2] = (0x0ff0 & data) >> 4
cmd[1] = (0xf000 & data) >> 12 | (0xf & addr) << 4
cmd[0] = (0xf & control) << 0 | (0xf & prefix) << 4
return cmd
# indexed by label number, mapping to DAC channel number
channel_map = (0,2,4,6,7,5,3,1)
write_mode = { 'WRITE': 0x0,
'UPDATE': 0x1,
'WRITE_UPDATE_ALL': 0x2,
'WRITE_UPDATE': 0x3 }
def write(self, addr, data, mode = write_mode['WRITE_UPDATE']):
addr = self.channel_map[addr]
cmd = self.build_command(mode, addr, data)
self.dev.writebytes(cmd)示例2: CpPhy
# 需要导入模块: from spidev import SpiDev [as 别名]
# 或者: from spidev.SpiDev import writebytes [as 别名]
#.........这里部分代码省略.........
self.spi.open(device, chipselect)
except IOError as e:
raise PhyError("Failed to open SPI device %d.%d: %s" %\
(device, chipselect, str(e)))
try:
self.spi.mode = 0;
self.spi.bits_per_word = 8;
self.spi.cshigh = False
self.spi.lsbfirst = False
self.spi.max_speed_hz = 200000;
except IOError as e:
try:
self.spi.close()
self.spi = None
except:
pass
raise PhyError("Failed to configure SPI device %d.%d: %s" %\
(device, chipselect, str(e)))
# Get the controller out of hardware reset
GPIO.output(self.GPIO_RESET, GPIO.HIGH)
time.sleep(0.2)
# Send a software reset
self.sendReset()
# Upload default config
self.profibusSetPhyConfig()
except:
GPIO.cleanup()
raise
def cleanup(self):
self.spi.close()
self.spi = None
GPIO.cleanup()
# Poll for received packet.
# timeout => In seconds. 0 = none, Negative = unlimited.
def poll(self, timeout=0):
limit = TimeLimited(timeout)
while GPIO.event_detected(self.GPIO_IRQ):
if limit.exceed():
return None
limit.sleep(0.001)
limit.add(0.5)
while not limit.exceed():
fc = self.spi.readbytes(1)[0]
if fc != CpPhyMessage.RPI_PACK_NOP:
break
else:
return None
reply = [ fc ]
reply.extend(self.spi.readbytes(CpPhyMessage.RASPI_PACK_HDR_LEN - 1))
payloadLen = reply[1] & 0xFF
if payloadLen:
reply.extend(self.spi.readbytes(payloadLen))
message = CpPhyMessage(0)
message.setRawData(reply)
if self.debug:
print("[PHY] recv msg:", message)
return message
def __sendMessage(self, message):
if self.debug:
print("[PHY] send msg:", message)
self.spi.writebytes(message.getRawData())
def sendReset(self):
self.__sendMessage(CpPhyMessage(CpPhyMessage.RPI_PACK_RESET))
reply = self.poll(timeout=-1)
if reply.fc != CpPhyMessage.RPI_PACK_ACK:
raise PhyError("Failed to reset PHY")
def profibusSetPhyConfig(self, baudrate=19200,
rxTimeoutMs=100,
bitErrorChecks=True,
rtsMode=PB_PHY_RTS_SENDING_HI):
try:
baudID = self.baud2id[baudrate]
except KeyError:
raise PhyError("Invalid baud-rate")
if rxTimeoutMs < 1 or rxTimeoutMs > 255:
raise PhyError("Invalid RX timeout")
payload = [ baudID,
rxTimeoutMs,
1 if bitErrorChecks else 0,
rtsMode & 0xFF ]
message = CpPhyMessage(CpPhyMessage.RPI_PACK_SETCFG, payload)
self.__sendMessage(message)
reply = self.poll(timeout=-1)
if reply.fc != CpPhyMessage.RPI_PACK_ACK:
raise PhyError("Failed to upload config")
def profibusSend_SDN(self, telegramData):
self.__sendMessage(CpPhyMessage(CpPhyMessage.RPI_PACK_PB_SDN,
telegramData))
def profibusSend_SRD(self, telegramData):
self.__sendMessage(CpPhyMessage(CpPhyMessage.RPI_PACK_PB_SRD,
telegramData))