This example creates and updates a standard Battery Level service containing a single GATT characteristic. The battery service transmits a device's battery level in percentage, with 100% being a fully charged battery and 0% being a fully drained battery. The canonical source for this example lives at https://github.com/ARMmbed/mbed-os-example-ble/tree/master/BLE_BatteryLevel

This example creates and updates a standard Battery Level service containing a single GATT characteristic.

The battery service transmits a device's battery level in percentage, with 100% being a fully charged battery and 0% being a fully drained battery.

Although the sample application runs on a BLE device, it doesn't show the device's real battery level (because that changes very slowly and will make for a dull example). Instead, it transmits a fake battery level that starts at 50% (half charged). Every half second, it increments the battery level, going in single increments until reaching 100% (as if the battery is charging). It then drops down to 20% to start incrementing again.

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-BatteryLevel/raw-file/a5ac4bf2e468/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 `BATTERY`.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/scan_result.png

figure 2 Scan results using nRF Master Control Panel 4.0.5

  • Establish a connection with your device.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/connection.png

figure 3 How to establish a connection using Master Control Panel 4.0.5

  • Discover the services and the characteristics on the device. The *Battery service* has the UUID 0x180F and includes the *Battery level* characteristic which has the UUID 0x2A19.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/discovery.png

figure 4 Representation of the Battery service using Master Control Panel 4.0.5

  • Register for the notifications sent by the *Battery level* characteristic.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/register_to_notifications.png

figure 5 How to register to notifications using Master Control Panel 4.0.5

  • You should see the battery level value change every half second. It begins at 50, goes up to 100 (in steps of 1), resets to 20 and so on.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/notifications.png

figure 6 Notifications view using Master Control Panel 4.0.5

If you can see the characteristic, and if its value is incrementing correctly, the application is working properly.

Revisions of mbed-os.lib

Revision Date Message Actions
57:b5b1c99d74c7 15 months ago Merge pull request #137 from adbridge/master File  Diff  Annotate
56:06f9f9fe6687 16 months ago Merge pull request #135 from adbridge/master File  Diff  Annotate
55:f17578ef784d 16 months ago Merge pull request #134 from cmonr/master File  Diff  Annotate
54:104348482690 17 months ago Merge pull request #133 from adbridge/master File  Diff  Annotate
53:6c17dd0c6700 17 months ago Merge pull request #129 from adbridge/master File  Diff  Annotate
51:13e52fb622ba 18 months ago Merge pull request #126 from ARMmbed/mbed-os-5.7.0-oob File  Diff  Annotate
50:beea1112dba7 18 months ago Merge pull request #119 from adbridge/master File  Diff  Annotate
49:5e53aded0e2f 19 months ago Merge pull request #115 from adbridge/master File  Diff  Annotate
48:5d8484f69181 19 months ago Merge pull request #113 from adbridge/master File  Diff  Annotate
47:1f5335ea3f67 19 months ago Merge pull request #110 from 0xc0170/master File  Diff  Annotate
45:74b28c5d183b 20 months ago Merge pull request #108 from adbridge/master File  Diff  Annotate
44:dfb005855532 20 months ago Merge pull request #106 from 0xc0170/master File  Diff  Annotate
43:7d141add5c76 21 months ago Merge pull request #103 from ARMmbed/5.6_sanity File  Diff  Annotate
42:973ff161ec9f 21 months ago Merge pull request #102 from adbridge/master File  Diff  Annotate
41:43801c2d0a0c 22 months ago Merge pull request #100 from 0xc0170/master File  Diff  Annotate
39:87d034cbd3fd 23 months ago Merge pull request #97 from 0xc0170/master File  Diff  Annotate
37:cbd4d01daf52 23 months ago Merge pull request #93 from adbridge/master File  Diff  Annotate
36:ba2e2bb2a6d1 24 months ago Merge pull request #89 from adbridge/master File  Diff  Annotate
34:2348da734fd2 24 months ago Merge pull request #88 from adbridge/master File  Diff  Annotate
32:d45aa4887a45 2017-06-08 Merge pull request #82 from adbridge/master File  Diff  Annotate
31:409bf0fe91b5 2017-05-25 Merge pull request #81 from adbridge/master File  Diff  Annotate
30:dacb92ff8643 2017-05-10 Merge pull request #79 from adbridge/master File  Diff  Annotate
28:b8afe00e80bb 2017-05-09 Merge pull request #77 from 0xc0170/master File  Diff  Annotate
27:fcf8cfa1baf7 2017-04-05 Merge pull request #70 from 0xc0170/master File  Diff  Annotate
24:9595ff320573 2017-03-14 Merge pull request #68 from adbridge/master File  Diff  Annotate
23:bcef5a68b77a 2017-03-09 Merge pull request #66 from ARMmbed/oob_test_mbed-os-5.4 File  Diff  Annotate
22:ed95da90a14b 2017-03-01 Merge pull request #55 from adbridge/master File  Diff  Annotate
20:a86a28b0ff71 2017-02-15 Merge pull request #52 from 0xc0170/master File  Diff  Annotate
19:e0b2279587b3 2017-02-02 Merge pull request #48 from adbridge/master File  Diff  Annotate
18:31c9e40c24b1 2017-01-26 Initial commit. File  Diff  Annotate
17:adfcc9cf1157 2016-12-15 Update mbed-os revision to mbed-os 5.3.0. File  Diff  Annotate
16:6d9331b1ee0f 2016-12-15 Merge pull request #42 from ARMmbed/mbed-os-5.3.0-rc3 File  Diff  Annotate
15:a87033d70a5e 2016-10-28 Updating mbed-os to mbed-os-5.2.1 File  Diff  Annotate
14:7ac634badd06 2016-10-24 Updating mbed-os to mbed-os-5.2.0 File  Diff  Annotate
13:eaa1343657a8 2016-10-24 Merge pull request #32 from ARMmbed/oob File  Diff  Annotate
12:3f66683285f4 2016-10-05 Updating mbed-os to mbed-os-5.1.5 File  Diff  Annotate
11:74a479c5b085 2016-09-16 Updating mbed-os to mbed-os-5.1.4 File  Diff  Annotate
10:57dd6cbde621 2016-08-20 Updating mbed-os to mbed-os-5.1.2 File  Diff  Annotate
9:8d5f2b68bde3 2016-08-19 Updating mbed-os to mbed-os-5.1.1 File  Diff  Annotate
8:26ff67ed6240 2016-08-05 Updating mbed-os to mbed-os-5.1.0 File  Diff  Annotate
6:c159081c2252 2016-08-03 Updating mbed-os to mbed-os-5.1.0-rc5 File  Diff  Annotate
5:4701f7db26f9 2016-07-30 Updating mbed-os to mbed-os-5.1.0-rc4 File  Diff  Annotate
4:52bffaff7f0b 2016-07-29 Merge branch 'master' of https://github.com/ARMmbed/mbed-os-example-ble File  Diff  Annotate
3:488ecd009a27 2016-07-28 Sync with mbed-os-5.1.0-rc3 File  Diff  Annotate
2:18b05b3173a8 2016-07-28 Merge branch 'master' of https://github.com/ARMmbed/mbed-os-example-ble File  Diff  Annotate
0:8113e6c77cd7 2016-07-26 Update example at tag mbed-os-5.0.1-rc1 File  Diff  Annotate