Multiple packets for TX

Author: Kevin Townsend

adafruit_bluefruitspi.py

@@ -146,31 +146,42 @@ def __init__(self, spi, cs, irq, reset, debug=False):
         self._spi_device = SPIDevice(spi, cs,
                                      baudrate=4000000, phase=0, polarity=0)
 
-    def cmd(self, cmd):
+    def _cmd(self, cmd):
         """
         Executes the supplied AT command, which must be terminated with
         a new-line character.
         Returns msgtype, rspid, rsp, which are 8-bit int, 16-bit int and a
         bytearray.
         :param cmd: The new-line terminated AT command to execute.
         """
-        # Make sure we stay within the 20 byte limit
-        if len(cmd) > 16:
-            # TODO: Split command into multiple packets
+        # Make sure we stay within the 255 byte limit
+        if len(cmd) > 127:
             if self._debug:
                 print("ERROR: Command too long.")
             raise ValueError('Command too long.')
 
-        # Construct the SDEP packet
-        struct.pack_into("<BHB16s", self._buf_tx, 0,
-                         MsgType.COMMAND, SDEPCommand.ATCOMMAND,
-                         len(cmd), cmd)
-        if self._debug:
-            print("Writing: ", [hex(b) for b in self._buf_tx])
+        more = 0x80 # More bit is in pos 8, 1 = more data available
+        pos = 0
+        while len(cmd) - pos:
+            # Construct the SDEP packet
+            if len(cmd) - pos <= 16:
+                # Last or sole packet
+                more = 0
+            plen = len(cmd) - pos
+            if plen > 16:
+                plen = 16
+            # Note the 'more' value in bit 8 of the packet len
+            struct.pack_into("<BHB16s", self._buf_tx, 0,
+                             MsgType.COMMAND, SDEPCommand.ATCOMMAND,
+                             plen | more, cmd[pos:pos+plen])
+            if self._debug:
+                print("Writing: ", [hex(b) for b in self._buf_tx])
+            # Update the position if there is data remaining
+            pos += plen
 
-        # Send out the SPI bus
-        with self._spi_device as spi:
-            spi.write(self._buf_tx, end=len(cmd) + 4)
+            # Send out the SPI bus
+            with self._spi_device as spi:
+                spi.write(self._buf_tx, end=len(cmd) + 4)
 
         # Wait up to 200ms for a response
         timeout = 0.2
@@ -231,10 +242,30 @@ def uarttx(self, txt):
         Sends the specific string out over BLE UART.
         :param txt: The new-line terminated string to send.
         """
-        return self.cmd("AT+BLEUARTTX="+txt+"\n")
+        return self._cmd("AT+BLEUARTTX="+txt+"\n")
 
     def uartrx(self):
         """
         Reads data from the BLE UART FIFO.
         """
-        return self.cmd("AT+BLEUARTRX\n")
+        return self._cmd("AT+BLEUARTRX\n")
+
+    def command(self, string):
+        try:
+            msgtype, msgid, rsp = self._cmd(string+"\n")
+            if msgtype == MsgType.ERROR:
+                raise RuntimeError("Error (id:{0})".format(hex(msgid)))
+            if msgtype == MsgType.RESPONSE:
+                return rsp
+        except RuntimeError as error:
+            raise RuntimeError("AT command failure: " + repr(error))
+
+    def command_check_OK(self, string, delay=0.0):
+        ret = self.command(string)
+        time.sleep(delay)
+        if not ret or not ret[-4:]:
+            raise RuntimeError("Not OK")
+        if ret[-4:] != b'OK\r\n':
+            raise RuntimeError("Not OK")
+        if ret[:-4]:
+            return str(ret[:-4], 'utf-8')

examples/bluefruitspi_simpletest.py

@@ -10,53 +10,34 @@
 rst = DigitalInOut(board.D4)
 bluefruit = BluefruitSPI(spi_bus, cs, irq, rst, debug=False)
 
-def send_command(string):
-    try:
-        msgtype, msgid, rsp = bluefruit.cmd(string+"\n")
-        if msgtype == MsgType.ERROR:
-            raise RuntimeError("Error (id:{0})".format(hex(msgid)))
-        if msgtype == MsgType.RESPONSE:
-            return rsp
-    except RuntimeError as error:
-        raise RuntimeError("AT command failure: " + repr(error))
-
-def command_check_OK(string, delay=0.0):
-    ret = send_command(string)
-    time.sleep(delay)
-    if not ret or not ret[-4:]:
-        raise RuntimeError("Not OK")
-    if ret[-4:] != b'OK\r\n':
-        raise RuntimeError("Not OK")
-    if ret[:-4]:
-        return str(ret[:-4], 'utf-8')
-
-# Initialize the device
+# Initialize the device and perform a factory reset
+print("Initializing the Bluefruit LE SPI Friend module")
 bluefruit.init()
-print(command_check_OK("AT+FACTORYRESET", 1.0))
-print(command_check_OK("ATI"))
-#print(command_check_OK("AT+GAPDEVNAME=ColorLamp"))
+bluefruit.command_check_OK("AT+FACTORYRESET", 1.0)
+print(bluefruit.command_check_OK("ATI"))
+print(bluefruit.command_check_OK("AT+GAPDEVNAME=ColorLamp"))
 
 while True:
-    # our main loop, if not connected, wait till we are
     connected = False
     dotcount = 0
     print("Waiting for a connection to Bluefruit LE Connect ...")
+    # Wait for a connection ...
     while not connected:
-        connected = int(command_check_OK("AT+GAPGETCONN")) == 1
+        connected = int(bluefruit.command_check_OK("AT+GAPGETCONN")) == 1
         dotcount += 1
         if dotcount == 79:
             print(".")
             dotcount = 0
         else:
             print(".", end="")
         time.sleep(0.5)
-    # Yay!
+    # Once connected, check for incoming BLE UART data
     print("\nConnected!")
     while connected:
-        command_check_OK("AT+BLEUARTTX=*")
-        resp = command_check_OK("AT+BLEUARTRX")
+        #bluefruit.command_check_OK("AT+BLEUARTTX=0123456789")
+        resp = bluefruit.command_check_OK("AT+BLEUARTRX")
         if resp:
             print(resp)
-        # Check connection status with a 1s delay
-        connected = int(command_check_OK("AT+GAPGETCONN", 0.5)) == 1
+        # Check connection status followed by a 500ms delay
+        connected = int(bluefruit.command_check_OK("AT+GAPGETCONN", 0.5)) == 1
     print("Connection lost.")