diff options
Diffstat (limited to 'dab752.py')
| -rw-r--r-- | dab752.py | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/dab752.py b/dab752.py new file mode 100644 index 0000000..c7bbb1b --- /dev/null +++ b/dab752.py @@ -0,0 +1,204 @@ +#!/usr/bin/env python + +import sys +import serial + +PACKETRETRY = 3 +MAXDATLEN = 128 +CRCPOLY = 0x810 +CRCINIT = 0xFFFF + +TX_ACKTIMEOUT = 3 #sec +RX_BYTETIMEOUT = 1 #sec + +STX_header = 0x02 +SOH_header = 0x01 +ETB_header = 0x17 +ETX_header = 0x03 +ACK_header = 0x06 +NAK_header = 0x15 + +def crc_initial(c): + crc = 0 + c = c << 8 + for j in range(8): + if (crc ^ c) & 0x8000: + crc = (crc << 1) ^ CRCPOLY + else: + crc = crc << 1 + c = c << 1 + crc = crc & 0xFFFF + return crc + +crc_table = [ crc_initial(i) for i in range(256) ] + +def get_crc(data): + crc = 0 + for d in data + [0xff, 0xff]: + if d < 0 or d > 255: + raise ValueError("data value out of bounds") + crc_h = crc >> 8 + crc = ((crc << 8) | d) & 0xFFFF + crc = crc ^ crc_table[crc_h] + return [crc >> 8, crc & 0xff] + +def check_crc(data): + return get_crc(data[:-2]) == data[-2:] + +class LLCP: + def __init__(self, port): + self.packet_id = 0 + self.serial = serial.Serial(port, 19200, timeout=0.5) + + def _tx_data(self, data): + print("TX %r" % data) + + self.serial.write(data) + + self.receive_packet() + + def receive_packet(self): + packet = [] + + header = self.serial.read() + if not header: + print("RX timeout") + return [] + header = ord(header) + packet.append(header) + + if header == SOH_header or \ + header == STX_header or \ + header == ETB_header or \ + header == ETX_header or \ + header == ACK_header or \ + header == NAK_header: + packet_id = self.serial.read() + if not packet_id: + print("packet_id timeout") + return [] + packet_id = ord(packet_id) + packet.append(packet_id) + + if header != ACK_header and header != NAK_header: + length = self.serial.read() + if not length: + print("length timeout") + return [] + length = ord(length) + if length > MAXDATLEN: + print("length invalid") + return [] + packet.append(length) + + data = self.serial.read(length) + if len(data) < length: + print("data length too short") + return [] + packet.extend(data) + + crch, crcl = self.serial.read(2) + if not crch or not crcl: + print("crc timeout") + return [] + packet.append(crch) + packet.append(crcl) + + if header == SOH_header: + print("SOH") + if header == STX_header: + print("STX") + if header == ETB_header: + print("ETB") + if header == ETX_header: + print("ETX") + if header == ACK_header: + print("ACK") + if header == NAK_header: + print("NAK") + + if check_crc(packet): + print("RX CRC Valid") + + if header != ACK_header and header != NAK_header: + print("Send ACK") + ack_data = [ACK_header, packet_id] + ack_data.extend(get_crc(ack_data)) + self._tx_data(ack_data) + else: + print("RX CRC INVALID") + + if header != ACK_header and header != NAK_header: + print("Send NAK") + ack_data = [NAK_header, packet_id] + ack_data.extend(get_crc(ack_data)) + self._tx_data(ack_data) + + print("RX %r" % packet) + return packet + + + + def transmit(self, message): + self.packet_id += 1 + data = [] + if len(message) < MAXDATLEN: + data.append(STX_header) + data.append(self.packet_id) + data.append(len(message)) + data.extend(message) + data.extend(get_crc(data)) + self._tx_data(data) + else: + h = SOH_header + sent_bytes = 0 + while sent_bytes < len(message): + message_part = message[sent_bytes:sent_bytes+MAXDATLEN] + + data.append(h) + data.append(self.packet_id) + data.append(len(message_part)) + data.extend(message_part) + data.extend(get_crc(data)) + + self._tx_data(data) + + sent_bytes += len(message_part) + h = ETB_header + if len(message) - sent_bytes < MAXDATLEN: + h = ETX_header + +llcp = LLCP("/dev/ttyUSB0") + +LnkRegister = 129 +GetComponentList = 39 +GetCurrentFrequency = 41 + +# Send a Link Register On message +print("Send a LnkRegister") +for i in range(4): + llcp.transmit([LnkRegister, 1]) + rx = llcp.receive_packet() + print() + if rx: + break + +print("Send invalid opcode") +llcp.transmit([78]) +llcp.receive_packet() +print() + +print("Send GetComponentList") +llcp.transmit([GetComponentList]) +llcp.receive_packet() +print() + +print("Send GetCurrentFrequency") +llcp.transmit([GetCurrentFrequency]) +llcp.receive_packet() +print() + +print("Send a LnkRegister Off") +llcp.transmit([LnkRegister, 0]) +llcp.receive_packet() +print() |