| from microbit import spi, sleep, pin16 | |
| import array | |
| import gc | |
| class LoRa(object): | |
| """ | |
| Radio - LoRa. Single channel. | |
| """ | |
| def __init__(self, Frequency=434.450, Mode=1): | |
| self.sending = False | |
| self.Frequency = Frequency | |
| self.currentMode = 0x81 | |
| self.Power = 0x88 | |
| pin16.write_digital(1) # Deselect CS | |
| spi.init() | |
| self.__writeRegister(0x41, 0x00) # REG_DIO_MAPPING_2 | |
| self.SetLoRaFrequency(Frequency) | |
| self.SetStandardLoRaParameters(Mode) | |
| def __readRegister(self, register): | |
| data = bytearray([register & 0x7F, 0]) | |
| pin16.write_digital(0) | |
| spi.write_readinto(data, data) | |
| pin16.write_digital(1) | |
| return data[1] | |
| def __writeRegister(self, register, value): | |
| pin16.write_digital(0) | |
| spi.write(bytearray([register | 0x80, value])) | |
| pin16.write_digital(1) | |
| def __setMode(self, newMode): | |
| if newMode != self.currentMode: | |
| if newMode == 0x83: # RF98_MODE_TX | |
| # TURN LNA OFF FOR TRANSMIT | |
| self.__writeRegister(0x0C, 0x00) # REG_LNA, LNA_OFF_GAIN | |
| # Set 10mW | |
| self.__writeRegister(0x09, self.Power) # REG_PA_CONFIG | |
| elif newMode == 0x85: # RF98_MODE_RX_CONTINUOUS | |
| # PA Off | |
| self.__writeRegister(0x09, 0x00) # REG_PA_CONFIG, PA_OFF_BOOST | |
| # Max LNA Gain | |
| self.__writeRegister(0x0C, 0x23) # REG_LNA, LNA_MAX_GAIN | |
| self.__writeRegister(0x01, newMode) # REG_OPMODE | |
| self.currentMode = newMode | |
| if newMode != 0x80: # RF98_MODE_SLEEP | |
| #while not self.DIO5.is_active: | |
| # pass | |
| # time.sleep(0.1) | |
| pass | |
| def SetLoRaFrequency(self, Frequency): | |
| self.__setMode(0x81) # RF98_MODE_STANDBY | |
| self.__setMode(0x80) # RF98_MODE_SLEEP | |
| self.__writeRegister(0x01, 0x80) # REG_OPMODE | |
| self.__setMode(0x81) # RF98_MODE_STANDBY | |
| FrequencyValue = int((Frequency * 7110656) / 434) | |
| self.__writeRegister(0x06, (FrequencyValue >> 16) & 0xFF) | |
| self.__writeRegister(0x07, (FrequencyValue >> 8) & 0xFF) | |
| self.__writeRegister(0x08, FrequencyValue & 0xFF) | |
| def SetLoRaParameters(self, ImplicitOrExplicit, ErrorCoding, Bandwidth, SpreadingFactor, LowDataRateOptimize): | |
| self.__writeRegister(0x1D, ImplicitOrExplicit | ErrorCoding | Bandwidth) | |
| self.__writeRegister(0x1E, SpreadingFactor | 0x04) | |
| self.__writeRegister(0x26, 0x04 | (0x08 if LowDataRateOptimize else 0)) | |
| self.__writeRegister(0x31, (self.__readRegister(0x31) & 0xF8) | (0x05 if (SpreadingFactor == 0x60) else 0x03)) | |
| self.__writeRegister(0x37, 0x0C if (SpreadingFactor == 0x60) else 0x0A) | |
| self.PayloadLength = 255 if ImplicitOrExplicit else 0 | |
| self.__writeRegister(0x22, self.PayloadLength) | |
| self.__writeRegister(0x1A, self.PayloadLength) | |
| def SetStandardLoRaParameters(self, Mode): | |
| if Mode == 0: | |
| self.SetLoRaParameters(0x00, 0x08, 0x30, 0xB0, True) | |
| elif Mode == 1: | |
| self.SetLoRaParameters(0x01, 0x02, 0x30, 0x60, False) | |
| elif Mode == 2: | |
| self.SetLoRaParameters(0x00, 0x08, 0x60, 0x80, False) | |
| def send_packet(self, packet): | |
| self.sending = True | |
| self.__setMode(0x81) # RF98_MODE_STANDBY) | |
| # map DIO0 to TxDone | |
| self.__writeRegister(0x40, 0x40) # REG_DIO_MAPPING_1 | |
| self.__writeRegister(0x0E, 0x00) # REG_FIFO_TX_BASE_AD | |
| self.__writeRegister(0x0D, 0x00) # REG_FIFO_ADDR_PTR | |
| # data = bytearray([0x80] + packet + [0] | |
| pin16.write_digital(0) | |
| # spi.write(data) | |
| spi.write(bytearray([0x80])) | |
| spi.write(packet) | |
| spi.write(bytearray([0])) | |
| pin16.write_digital(1) | |
| self.__writeRegister(0x22, self.PayloadLength if self.PayloadLength else len(packet)) # REG_PAYLOAD_LENGTH | |
| self.__setMode(0x83) # RF98_MODE_TX | |
| def send_text(self, sentence): | |
| self.send_packet(bytearray(sentence)) | |
| sleep(1000) | |
| print("LoRa Test Program") | |
| sleep(1000) | |
| print("Create LoRa object") | |
| MaxFree = 0 | |
| MyLoRa = LoRa() | |
| while True: | |
| MaxFree = max(MaxFree, gc.mem_free()) | |
| print(gc.mem_free(), MaxFree) | |
| print("Send message") | |
| MyLoRa.send_text("$$Hello World!\n") | |
| print("Sent") | |
| sleep(2000) | |
| print() | |
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