Bluetooth Low Energy
A template for applications where some small amount of data needs to be notified to a phone app over BLE. It is a good starting point for notifications.
Dependencies: BLE_API mbed nRF51822
Demo for an Input Service
To help you create your own BLE services, we've created a series of service templates. The *input service template* demonstrates the use of a simple input (boolean values) from a read-only characteristic.
The template covers:
1. Setting up advertising and connection states.
2. Assigning UUIDs to the service and its characteristic.
3. Creating an input characteristic: read-only, boolean, with notifications. This characteristic is updated according to the button's state.
4. Constructing a service class and adding it to the BLE stack.
Diff: main.cpp
- Revision:
- 9:0f6951db24f1
- Parent:
- 8:a7ba7aaba460
- Child:
- 10:7943b5c1117a
--- a/main.cpp Tue Sep 29 09:58:02 2015 +0000
+++ b/main.cpp Fri Oct 09 13:37:52 2015 +0000
@@ -25,16 +25,27 @@
const static char DEVICE_NAME[] = "Button";
static const uint16_t uuid16_list[] = {ButtonService::BUTTON_SERVICE_UUID};
+enum {
+ RELEASED = 0,
+ PRESSED,
+ IDLE
+};
+static uint8_t buttonState = IDLE;
+
ButtonService *buttonServicePtr;
void buttonPressedCallback(void)
{
- buttonServicePtr->updateButtonState(true);
+ /* Note that the buttonPressedCallback() executes in interrupt context, so it is safer to access
+ * BLE device API from the main thread. */
+ buttonState = PRESSED;
}
void buttonReleasedCallback(void)
{
- buttonServicePtr->updateButtonState(false);
+ /* Note that the buttonReleasedCallback() executes in interrupt context, so it is safer to access
+ * BLE device API from the main thread. */
+ buttonState = RELEASED;
}
void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params)
@@ -70,6 +81,11 @@
ble.gap().startAdvertising();
while (true) {
+ if (buttonState!=IDLE) {
+ buttonServicePtr->updateButtonState(buttonState);
+ buttonState = IDLE;
+ }
+
ble.waitForEvent();
}
}