92 lines
3.2 KiB
Python
92 lines
3.2 KiB
Python
"""
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GNSS
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Micropython library for the GNSS(NMEA0183/GPS,DBS)
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=======================================================
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@dahanzimin From the Mixly Team
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"""
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from time import sleep_ms
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from ubinascii import unhexlify
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class NMEA0183:
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def __init__(self, uart, baudrate=9600, timeout=200):
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self._uart=uart
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self._uart.init(baudrate=baudrate, timeout=timeout, rxbuf=1024)
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self.time=[None, None, None, None, None, None]
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self.locate=['', None, '', None, None, None, None] #0'1经度,2'3纬度,4海拔m,5速度m/s,6航向°
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self.status=[False, ' ', 0] #有效标注,定位模式,卫星量
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if not self._chip_id():
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raise AttributeError("Cannot find a GNSS device")
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def _crc8(self, buffer):
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'''对数据进行CRC校验'''
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crc = 0x00
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for byte in buffer:
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crc ^= byte
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return crc & 0xff
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def _chip_id(self):
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for _ in range(10):
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sleep_ms(300)
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if self.any():
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self._uart.write(("$PCAS02,1000*2E\r\n").encode()) #更新频率1HZ
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self._uart.write("$PCAS03,1,0,0,0,1,0,0,0,0,0,,,0,0*02\r\n".encode()) #只加载GNGGA和GNRMC
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return True
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def _judge(self, buffer, dlen):
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try:
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data=buffer.strip().decode().split(',')
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if len(data) == dlen:
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if unhexlify(data[-1][-2:])[0] == self._crc8(buffer[1:-5]):
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return True,data
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return False,None
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except :
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return False,None
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def any(self):
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flag_rmc,flag_gga=False,False
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while self._uart.any():
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_data=self._uart.readline()
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if b'$GNGGA' in _data:
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flag_gga,data=self._judge(_data, 15)
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#print("GGA----",flag_gga)
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if flag_gga:
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self.time[3]= int(data[1][0:2]) if data[1] else None
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self.time[4]= int(data[1][2:4]) if data[1] else None
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self.time[5]= int(data[1][4:6]) if data[1] else None
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self.locate[0]= data[5]
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self.locate[1]= int(data[4][:3])+int(data[4][3:].replace('.',''))/6000000 if data[4] else None
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self.locate[2]= data[3]
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self.locate[3]= int(data[2][:2])+int(data[2][2:].replace('.',''))/6000000 if data[2] else None
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self.locate[4]= float(data[9]) if data[3] else None
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self.status[0]= False if '0' in data[6] else True
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self.status[2]= int(data[7])
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if b'$GNRMC' in _data:
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flag_rmc,data=self._judge(_data, 14)
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#print("RMC----",flag_rmc)
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if flag_rmc:
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self.time[0]= int(data[9][4:6])+2000 if data[9] else None
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self.time[1]= int(data[9][2:4]) if data[9] else None
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self.time[2]= int(data[9][0:2]) if data[9] else None
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self.time[3]= int(data[1][0:2])+8 if data[1] else None
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self.time[4]= int(data[1][2:4]) if data[1] else None
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self.time[5]= int(data[1][4:6]) if data[1] else None
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self.locate[0]= data[6]
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self.locate[1]= int(data[5][:3])+int(data[5][3:].replace('.',''))/6000000 if data[5] else None
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self.locate[2]= data[4]
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self.locate[3]= int(data[3][:2])+int(data[3][2:].replace('.',''))/6000000 if data[3] else None
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self.locate[5]= round(float(data[7])*0.514, 2) if data[7] else None
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self.locate[6]= float(data[8]) if data[8] else None
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self.status[0]= False if 'V' in data[2] else True
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self.status[1]= data[12]
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return flag_rmc | flag_gga
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def time(self):
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return tuple(self.time)
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def locate(self):
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return tuple(self.locate)
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def status(self):
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return tuple(self.status)
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