Update UART example

examples/bluefruitconnect_uart.py

@@ -1,15 +1,20 @@
 # Basic example for using the BLE Connect UART
 # To use, start this program, and start the Adafruit Bluefruit LE Connect app.
-# Connect, and then select UART
+# Connect, and then select UART. Any text received FROM the connected device
+# will be displayed. Periodically, text is sent TO the connected device.
 
+import time
 from adafruit_ble import BLERadio
 from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
 from adafruit_ble.services.nordic import UARTService
 
+SEND_RATE = 10  # how often in seconds to send text
+
 ble = BLERadio()
 uart_server = UARTService()
 advertisement = ProvideServicesAdvertisement(uart_server)
 
+count = 0
 while True:
     print("WAITING...")
     # Advertise when not connected.
@@ -22,12 +27,21 @@
     print("CONNECTED")
 
     # Loop and read packets
+    last_send = time.monotonic()
     while ble.connected:
+        # INCOMING (RX) check for incoming text
         if uart_server.in_waiting:
             raw_bytes = uart_server.read(uart_server.in_waiting)
             text = raw_bytes.decode().strip()
-            print("raw bytes =", raw_bytes)
-            print("text =", text)
+            # print("raw bytes =", raw_bytes)
+            print("RX:", text)
+        # OUTGOING (TX) periodically send text
+        if time.monotonic() - last_send > SEND_RATE:
+            text = "COUNT = {}\r\n".format(count)
+            print("TX:", text.strip())
+            uart_server.write(text.encode())
+            count += 1
+            last_send = time.monotonic()
 
     # Disconnected
     print("DISCONNECTED")