Initial Commit

Signed-off-by: Chris Fiege <chris@tinyhost.de>

.gitignore

+*.pyc

sa868/__init__.py

+import argparse
+import serial
+
+class SA868(object):
+
+    class AtException(Exception):
+        pass
+
+    class CommandException(Exception):
+        pass
+
+    def __init__(self, port):
+        self._serial = serial.Serial(port, 9200, timeout=1)
+
+    def _check_freq_range(self, freq):
+        if (freq >= 400 and freq <= 480) or (freq >= 134 and freq <=174):
+            if (freq * 1000) % 12.5 == 0:
+                return True
+            else:
+                raise Exception("Frequency is not a multiple of 12.5kHz")
+        else:
+            raise Exception("Frequency out of bounds")
+
+    def _check_squelsh_range(self, squelsh):
+        if squelsh >= 0 and squelsh <= 8:
+            return True
+        else:
+            raise Exception("Squelsh out of range")
+
+    def _check_volume_range(self, volume):
+        if volume >= 0 and volume <=8:
+            return True
+        else:
+            raise Exception("Volume out of range")
+
+    def _command_return(self, command, expected_return):
+        command = "{}\r\n".format(command)
+        self._serial.write(command.encode())
+        ret = self._serial.readline()
+        ret = bytes([x for x in ret if x is not 0x00])
+        ret = ret.decode().strip()
+        if ret.startswith(expected_return):
+            return ret.split(expected_return)[-1]
+        else:
+            raise SA868.AtException("Device returned wrong answer: '{}'".format(ret))
+
+    def _command(self, command, expected_return):
+        ret = self._command_return(command, expected_return)
+
+        if ret == "0":
+            return True
+        else:
+            raise SA868.CommandException("Command returned non-zero: {}".format(ret))
+
+    def ping(self):
+        self._command("AT+DMOCONNECT", "+DMOCONNECT:")
+
+    def sweep(self, frequency):
+        self._check_freq_range(frequency)
+
+        return int(self._command_return(
+            "S+{:8.4f}".format(frequency),
+            "S="))
+
+    def set_group(self, rx_freq, tx_freq, squelsh):
+        self._check_freq_range(rx_freq)
+        self._check_freq_range(tx_freq)
+        self._check_squelsh_range(squelsh)
+
+        self._command("AT+DMOSETGROUP=0,{:8.4f},{:8.4f},0000,{},0000".format(tx_freq, rx_freq, squelsh),
+                      "+DMOSETGROUP:")
+
+    def set_volume(self, volume):
+        self._check_volume_range(volume)
+
+        self._command("AT+DMOSETVOLUME={}".format(volume), "+DMOSETVOLUME:")
+
+    def get_rssi(self):
+        return int(self._command_return("AT+RSSI?","RSSI="))
+
+    def set_filter(self, pre_de_emphasis, lowpass, highpass):
+        self._command("AT+SETFILTER={},{},{}".format(
+            0 if pre_de_emphasis else 1,
+            0 if lowpass else 1,
+            0 if highpass else 1),
+        "+DMOSETFILTER:")
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("tty", help="/dev/tty* to use")
+    parser.add_argument("--set-rxtx", help="Set Rx and Tx frequencies and squelsh", nargs=3, metavar=("rx_freq", "tx_freq", "squelsh"), type=float)
+    parser.add_argument("--set-volume", help="Sets the speaker volume to the given level", type=int)
+    parser.add_argument("--set-filter", help="Sets the pre-/de-emphasis, highpass- and lowpass-filter. Use {off, on}", nargs=3, metavar=("pre_de_emphasis", "lowpass", "highpass"))
+    parser.add_argument("--get-rssi", help="Prints the current RSSI to STDOUT", action="store_true")
+    parser.add_argument("--no-ping", help="Disables the initial ping of the device", action="store_true")
+    args = parser.parse_args()
+
+    s = SA868(args.tty)
+    if not args.no_ping:
+        s.ping()
+
+    if args.set_rxtx:
+        s.set_group(*args.set_rxtx)
+
+    if args.set_volume:
+        s.set_volume(args.set_volume)
+
+    if args.set_filter:
+        filter = [True if x in ["1", "on"] else False for x in args.set_filter]
+        s.set_filter(*filter)
+
+    if args.get_rssi:
+        print(s.get_rssi())
+
+if __name__ == "__main__":
+    main()