This application shows how to use GAP to transmit a simple value to disconnected peer listening for advertisement every time that a value is updated. The canonical source for this example lives at: https://github.com/ARMmbed/mbed-os-example-ble/tree/master/BLE_GAPButton

Button count over GAP

This application shows how to use GAP to transmit a simple value to disconnected peer listening for advertisement every time that a value is updated:

  • The value is a count of how many times a button on the device was pressed (the code actually monitors the button's releases, not press downs).
  • We transmit the value in the SERVICE_DATA field of the advertising payload.

Running the application

Requirements

The sample application can be seen on any BLE scanner on a smartphone. If you don't have a scanner on your phone, please install :

- nRF Master Control Panel for Android.

- LightBlue for iPhone.

Hardware requirements are in the main readme.

Building instructions

Building with mbed CLI

If you'd like to use mbed CLI to build this, then you should refer to the main readme. The instructions here relate to using the developer.mbed.org Online Compiler

In order to build this example in the mbed Online Compiler, first import the example using the ‘Import’ button on the right hand side.

Next, select a platform to build for. This must either be a platform that supports BLE, for example the NRF51-DK, or one of the following:

List of platforms supporting Bluetooth Low Energy

Or you must also add a piece of hardware and the supporting library that includes a Bluetooth Low Energy driver for that hardware, for example the K64F or NUCLEO_F401RE with the X-NUCLEO-IDB05A1

List of components supporting Bluetooth Low Energy.

Once you have selected your platform, compile the example and drag and drop the resulting binary onto your board.

For general instructions on using the mbed Online Compiler, please see the mbed Handbook

Checking for success

Note: Screens captures depicted below show what is expected from this example if the scanner used is nRF Master Control Panel version 4.0.5. If you encounter any difficulties consider trying another scanner or another version of nRF Master Control Panel. Alternative scanners may require reference to their manuals.

  • Build the application and install it on your board as explained in the building instructions.
  • Open the BLE scanner on your phone.
  • Start a scan.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-GAPButton/raw-file/8f898b781de2/img/start_scan.png

figure 1 How to start scan using nRF Master Control Panel 4.0.5.

  • Find your device; it should be named `GAPButton`; and look at the advertisement broadcasted by your device (there is no need to connect to your device).

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-GAPButton/raw-file/8f898b781de2/img/discovery.png

figure 2 Scan results using nRF Master Control Panel 4.0.5.

  • The Service Data field of the advertisement packet broadcasted by your device reflects the button press count. The starting value is 0.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-GAPButton/raw-file/8f898b781de2/img/initial_state.png

figure 3 Initial state of the button using nRF Master Control Panel 4.0.5.

  • Press the button on the device.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-GAPButton/raw-file/8f898b781de2/img/first_press.png

figure 3 State after 1 button press using nRF Master Control Panel 4.0.5.

  • The Service Data field value of the advertisement packet should change every time you press the button.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-GAPButton/raw-file/8f898b781de2/img/result.png

figure 3 State after 6 button press using nRF Master Control Panel 4.0.5.

Note

Since broadcasting is not reliable and your phone may scan intermittently, it is possible that your phone will miss button updates.

Committer:
mbed_official
Date:
Fri Oct 18 15:01:02 2019 +0100
Revision:
85:c66873cfddb4
Parent:
47:70f571463f31
Merge pull request #268 from trowbridgec/add-ep-agora

Add support for the Embedded Planet EP_AGORA target
.
Commit copied from https://github.com/ARMmbed/mbed-os-example-ble

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 3:f0ed4199b362 1 # Button count over GAP
mbed_official 3:f0ed4199b362 2
mbed_official 47:70f571463f31 3 This application shows how to use GAP to transmit a simple value to a disconnected peer listening for advertisement every time that a value is updated:
mbed_official 3:f0ed4199b362 4
mbed_official 3:f0ed4199b362 5 1. The value is a count of how many times a button on the device was pressed (the code actually monitors the button's releases, not press downs).
mbed_official 3:f0ed4199b362 6
mbed_official 3:f0ed4199b362 7 1. We transmit the value in the SERVICE_DATA field of the advertising payload.
mbed_official 3:f0ed4199b362 8
mbed_official 3:f0ed4199b362 9 # Running the application
mbed_official 3:f0ed4199b362 10
mbed_official 3:f0ed4199b362 11 ## Requirements
mbed_official 3:f0ed4199b362 12
mbed_official 3:f0ed4199b362 13 The sample application can be seen on any BLE scanner on a smartphone. If you don't have a scanner on your phone, please install :
mbed_official 3:f0ed4199b362 14
mbed_official 3:f0ed4199b362 15 - [nRF Master Control Panel](https://play.google.com/store/apps/details?id=no.nordicsemi.android.mcp) for Android.
mbed_official 3:f0ed4199b362 16
mbed_official 3:f0ed4199b362 17 - [LightBlue](https://itunes.apple.com/gb/app/lightblue-bluetooth-low-energy/id557428110?mt=8) for iPhone.
mbed_official 3:f0ed4199b362 18
mbed_official 3:f0ed4199b362 19 Hardware requirements are in the [main readme](https://github.com/ARMmbed/mbed-os-example-ble/blob/master/README.md).
mbed_official 3:f0ed4199b362 20
mbed_official 7:d4dd083eba53 21 ### Porting this example on new boards
mbed_official 7:d4dd083eba53 22
mbed_official 47:70f571463f31 23 This example requires a board with at least 1 button to work. While the pin name of the button is defined for the `NRF51_DK`, `NRF52_DK`, `K64F` and `NUCLEO_F401RE`, it is not specified for other boards.
mbed_official 7:d4dd083eba53 24
mbed_official 7:d4dd083eba53 25 It is easy to add the button configuration for your board:
mbed_official 7:d4dd083eba53 26 * Open the file named `mbed_app.json` at the root of this example.
mbed_official 7:d4dd083eba53 27 * In the section `target_overides` add a new object named after your target if it doesn't exist. This object contain overridden parameters for your target.
mbed_official 7:d4dd083eba53 28 * Override the property `ble_button_pin_name` in your target object. The value of the property should be equal to the pin name to use as a button.
mbed_official 7:d4dd083eba53 29
mbed_official 7:d4dd083eba53 30 As an example, this is the JSON bit which has to be added in the `target_overrides` section of `mbed_app.json` for a `NUCLEO_F411RE` board.
mbed_official 7:d4dd083eba53 31
mbed_official 7:d4dd083eba53 32 ```json
mbed_official 7:d4dd083eba53 33 "NUCLEO_F411RE": {
mbed_official 7:d4dd083eba53 34 "ble_button_pin_name": "USER_BUTTON"
mbed_official 7:d4dd083eba53 35 }
mbed_official 7:d4dd083eba53 36 ```
mbed_official 7:d4dd083eba53 37
mbed_official 7:d4dd083eba53 38 <span> **Note:** You can get more informations about the configuration system in the [documentation](https://github.com/ARMmbed/mbed-os/blob/master/docs/config_system.md)</span>
mbed_official 7:d4dd083eba53 39
mbed_official 7:d4dd083eba53 40 <span> **Important:** If your target use an ST BLE shield, other parameters have to be overridden for your target. More information are available in the global [README](https://github.com/ARMmbed/mbed-os-example-ble/blob/master/README.md#targets-for-ble)</span>
mbed_official 7:d4dd083eba53 41
mbed_official 7:d4dd083eba53 42
mbed_official 3:f0ed4199b362 43 ## Building instructions
mbed_official 3:f0ed4199b362 44
mbed_official 3:f0ed4199b362 45 Building instructions for all samples are in the [main readme](https://github.com/ARMmbed/mbed-os-example-ble/blob/master/README.md).
mbed_official 3:f0ed4199b362 46
mbed_official 3:f0ed4199b362 47 ## Checking for success
mbed_official 3:f0ed4199b362 48
mbed_official 3:f0ed4199b362 49 **Note:** Screens captures depicted below show what is expected from this example if the scanner used is *nRF Master Control Panel* version 4.0.5. If you encounter any difficulties consider trying another scanner or another version of nRF Master Control Panel. Alternative scanners may require reference to their manuals.
mbed_official 3:f0ed4199b362 50
mbed_official 3:f0ed4199b362 51 1. Build the application and install it on your board as explained in the building instructions.
mbed_official 3:f0ed4199b362 52
mbed_official 3:f0ed4199b362 53 1. Open the BLE scanner on your phone.
mbed_official 3:f0ed4199b362 54
mbed_official 3:f0ed4199b362 55 1. Start a scan.
mbed_official 3:f0ed4199b362 56
mbed_official 3:f0ed4199b362 57 ![](img/start_scan.png)
mbed_official 3:f0ed4199b362 58
mbed_official 3:f0ed4199b362 59 **figure 1** How to start scan using nRF Master Control Panel 4.0.5.
mbed_official 3:f0ed4199b362 60
mbed_official 3:f0ed4199b362 61 1. Find your device; it should be named `GAPButton`; and look at the advertisement broadcasted by your device (there is no need to connect to your device).
mbed_official 3:f0ed4199b362 62
mbed_official 3:f0ed4199b362 63 ![](img/discovery.png)
mbed_official 3:f0ed4199b362 64
mbed_official 3:f0ed4199b362 65 **figure 2** Scan results using nRF Master Control Panel 4.0.5.
mbed_official 3:f0ed4199b362 66
mbed_official 3:f0ed4199b362 67 1. The Service Data field of the advertisement packet broadcasted by your device reflects the button press count. The starting value is 0.
mbed_official 3:f0ed4199b362 68
mbed_official 3:f0ed4199b362 69 ![](img/initial_state.png)
mbed_official 3:f0ed4199b362 70
mbed_official 3:f0ed4199b362 71 **figure 3** Initial state of the button using nRF Master Control Panel 4.0.5.
mbed_official 3:f0ed4199b362 72
mbed_official 3:f0ed4199b362 73 1. Press the button on the device.
mbed_official 3:f0ed4199b362 74
mbed_official 3:f0ed4199b362 75 ![](img/first_press.png)
mbed_official 3:f0ed4199b362 76
mbed_official 3:f0ed4199b362 77 **figure 3** State after 1 button press using nRF Master Control Panel 4.0.5.
mbed_official 3:f0ed4199b362 78
mbed_official 3:f0ed4199b362 79 1. The Service Data field value of the advertisement packet should change every time you press the button.
mbed_official 3:f0ed4199b362 80
mbed_official 3:f0ed4199b362 81 ![](img/result.png)
mbed_official 3:f0ed4199b362 82
mbed_official 3:f0ed4199b362 83 **figure 3** State after 6 button press using nRF Master Control Panel 4.0.5.
mbed_official 3:f0ed4199b362 84
mbed_official 3:f0ed4199b362 85 ## Note
mbed_official 3:f0ed4199b362 86
mbed_official 3:f0ed4199b362 87 Since broadcasting is not reliable and your phone may scan intermittently, it is possible that your phone will miss button updates.