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
81:99e70947653f 2019-08-15 Merge pull request #252 from donatieng/mbed_os_update File  Diff  Annotate
80:1170721a1db6 2019-02-27 Updating mbed-os to mbed-os-5.11.5 File  Diff  Annotate
79:816f08ee21bd 2019-02-25 Merge pull request #217 from adbridge/master File  Diff  Annotate
78:b300982f35aa 2019-02-13 Updating mbed-os to mbed-os-5.11.2 File  Diff  Annotate
77:634599d24f93 2019-01-14 Merge pull request #207 from adbridge/master File  Diff  Annotate
76:e489712bcbcf 2019-01-14 Merge pull request #208 from ARMmbed/mbed-os-5.11.0-oob File  Diff  Annotate
75:a91805e80107 2018-12-14 Updating mbed-os to mbed-os-5.10.4 File  Diff  Annotate
73:e76cb6fa4310 2018-11-07 Merge pull request #189 from ARMmbed/donatieng-patch-1 File  Diff  Annotate
72:15a6111a679e 2018-10-22 Merge pull request #187 from cmonr/master File  Diff  Annotate
71:d083bf017556 2018-09-26 Merge pull request #183 from ARMmbed/mbed-os-5.10.0-oob File  Diff  Annotate
69:3505c21fe0fc 2018-08-29 Merge pull request #172 from 0xc0170/master File  Diff  Annotate
68:6b40c380545f 2018-08-23 Updating mbed-os to mbed-os-5.9.5 File  Diff  Annotate
67:2a65e8c6ab62 2018-08-08 Merge pull request #168 from cmonr/master File  Diff  Annotate
66:0a5868d3e297 2018-07-18 Merge pull request #166 from cmonr/master File  Diff  Annotate
65:a7d40a1e5bb3 2018-07-06 Merge pull request #163 from adbridge/master File  Diff  Annotate
64:31a307a8a873 2018-06-22 Merge pull request #160 from adbridge/master File  Diff  Annotate
63:4a5567d7354e 2018-06-20 Merge pull request #159 from ARMmbed/mbed-os-5.9.0-oob File  Diff  Annotate
62:42a62fe25296 2018-06-11 Merge pull request #158 from adbridge/master File  Diff  Annotate
61:2430255789dc 2018-06-05 Initial commit. File  Diff  Annotate
60:b3931d7acd8d 2018-04-04 Merge pull request #141 from adbridge/master File  Diff  Annotate
59:7288d623447c 2018-04-04 Merge pull request #142 from ARMmbed/mbed-os-5.8.0-oob File  Diff  Annotate
58:0e470fa26478 2018-03-23 Merge pull request #139 from cmonr/master File  Diff  Annotate
57:b5b1c99d74c7 2018-03-23 Merge pull request #137 from adbridge/master File  Diff  Annotate
56:06f9f9fe6687 2018-02-13 Merge pull request #135 from adbridge/master File  Diff  Annotate
55:f17578ef784d 2018-01-31 Merge pull request #134 from cmonr/master File  Diff  Annotate
54:104348482690 2018-01-17 Merge pull request #133 from adbridge/master File  Diff  Annotate
53:6c17dd0c6700 2018-01-09 Merge pull request #129 from adbridge/master File  Diff  Annotate
51:13e52fb622ba 2017-12-20 Merge pull request #126 from ARMmbed/mbed-os-5.7.0-oob File  Diff  Annotate
50:beea1112dba7 2017-12-05 Merge pull request #119 from adbridge/master File  Diff  Annotate
49:5e53aded0e2f 2017-11-23 Merge pull request #115 from adbridge/master File  Diff  Annotate
48:5d8484f69181 2017-11-07 Merge pull request #113 from adbridge/master File  Diff  Annotate
47:1f5335ea3f67 2017-11-03 Merge pull request #110 from 0xc0170/master File  Diff  Annotate
45:74b28c5d183b 2017-10-11 Merge pull request #108 from adbridge/master File  Diff  Annotate
44:dfb005855532 2017-09-29 Merge pull request #106 from 0xc0170/master File  Diff  Annotate
43:7d141add5c76 2017-09-20 Merge pull request #103 from ARMmbed/5.6_sanity File  Diff  Annotate
42:973ff161ec9f 2017-09-08 Merge pull request #102 from adbridge/master File  Diff  Annotate
41:43801c2d0a0c 2017-08-08 Merge pull request #100 from 0xc0170/master File  Diff  Annotate
39:87d034cbd3fd 2017-07-19 Merge pull request #97 from 0xc0170/master File  Diff  Annotate
37:cbd4d01daf52 2017-07-11 Merge pull request #93 from adbridge/master File  Diff  Annotate
36:ba2e2bb2a6d1 2017-06-22 Merge pull request #89 from adbridge/master File  Diff  Annotate
34:2348da734fd2 2017-06-20 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