B4A Library [B4X] BLE 2 - Bluetooth Low Energy

Erel · Nov 2, 2015

This library replaces the previous BLE library.
It is simpler to use and it is more powerful. Its API is based on B4i iBLE library which makes it easy to reuse B4i code.

See the iBLE tutorial: https://www.b4x.com/android/forum/threads/ble-bluetooth-low-energy-library.46099/#content

Tips & Notes

- You can call Manager.Scan2 with AllowDuplicates set to True if you want to monitor the state of an unconnected device.
- The AdvertisingData map in DeviceFound event holds pairs of integers as keys (data types) and bytes arrays as values.
- Call ReadData2 if you are only interested in a single characteristic.
- BLE is only supported on Android 4.3+.

See the attached example. Note that the important code in in the Starter service module.

Edit:

A new version of BLE_Example was uploaded. targetSdkVersion is now set to 29
Setting the targetSdkVersion to 29 requires some changes:

1. Add the fine location permission in the manifest editor.
2. Request this permission with RuntimePermissions.

Otherwise scanning will fail with a message visible in the unfiltered logs.

BLE2 is an internal library now. It is included in the IDE.

Example is based on B4XPages and will work with B4A and B4i.

Updates:
- Example updated with targetSdkVersion = 31. Note the permissions in the manifest editor:

B4X:

AddPermission(android.permission.ACCESS_FINE_LOCATION)
AddPermission(android.permission.BLUETOOTH_SCAN)
AddPermission(android.permission.BLUETOOTH_CONNECT)

And requesting at runtime:

B4X:

Dim Permissions As List
Dim phone As Phone
If phone.SdkVersion >= 31 Then
    Permissions = Array("android.permission.BLUETOOTH_SCAN", "android.permission.BLUETOOTH_CONNECT", rp.PERMISSION_ACCESS_FINE_LOCATION)
Else
    Permissions = Array(rp.PERMISSION_ACCESS_FINE_LOCATION)
End If
For Each per As String In Permissions
    rp.CheckAndRequest(per)
    Wait For B4XPage_PermissionResult (Permission As String, Result As Boolean)
    If Result = False Then
        ToastMessageShow("No permission: " & Permission, True)
        Return
    End If
Next

Erel · Dec 18, 2015

It is set automatically based on the WriteWithoutResponse property. Do you see this property with the code I posted?

Turbo3 · Dec 18, 2015

The device that works report 0x1A for the property. The one that hangs waiting for a response reports 0x3A for the property. Could that make a difference?

Both these devices work fine with iBLE 1.31.

Erel · Dec 18, 2015

It should use "write with response" for both characteristics (based on the properties). How are you writing to this characteristic in B4i?

Turbo3 · Dec 18, 2015

Basically the same line of code for both B4i and B4A.

B4X:

B4i: manager.WriteDataWithResponse(CurService,CurCharWrite,ATCmdOut.GetBytes("UTF8"))
B4A: Starter.manager.WriteData(Starter.CurService,Starter.CurCharWrite,ATCmdOut.GetBytes("UTF8"))

Could you add the WriteDataWithResponse to B4A just to see if forcing it makes a difference?

Turbo3 · Dec 18, 2015

Erel, Can you please add two additional WriteData commands, one WithResponse and another WithoutResponse. That way I can test and see if either of those writes work. If not then the problem is somewhere else.

KY Leng · Dec 19, 2015

Good evening Erel,

In the previous version of BleExtEx (version: 1.10), we can read/write data (serial data from/to BLE device) by using

'Read:
Sub Manager_CharacteristicChanged (Characteristic As BleCharacteristic)
Dim StrIn As String
StrIn = Characteristic.GetStringValue(0)
Log(" RxD <" & StrIn & ">")
End Sub

'Wite:
cwrite.SetStringValue(StrOutBT)
Manager.WriteCharacteristic(cwrite)

With this new BLE2 (version: 1.10), could you please tell us how to do it?
Note: The reason I move from BleExtEx to BLE2 is that BleExtEx could not allow Nexus Android Version 6.0.1 to find BLE device.
And it seem that all Android Version 6.0.1 could not find BLE device with EleExtEx library.

Looking forward to hearing from you soon...

Erel · Dec 20, 2015

@KY Leng see this tutorial: https://www.b4x.com/android/forum/threads/ble-bluetooth-low-energy-library.46099/#content
For further help please start a new thread.

@Turbo3 Replace the existing jar with the one attached (copy it to the internal libraries folder).
It allows getting the characteristics with JavaObject:

B4X:

Dim jo As JavaObject = BleManager1
Dim ser As JavaObject = jo.RunMethod("getService", Array(ServiceId))
Dim chrc As JavaObject = jo.RunMethod("getChar", Array (ser, CharacteristicId))
chrc.RunMethod("setWriteType", Array (2)) '2 = with response, 1 = no response
'... now  call the regular Write method.

Turbo3 · Dec 20, 2015

By "internal libraries folder" I assume you mean the Libraries folder under Basic4android where the current BLE2.jar was located.

With the new BLE2.jar JavaObject is an unknown type.

==================

Never mind. I needed to enable the JavaObject library.

I will test in the morning.

DonManfred · Dec 20, 2015

Turbo3 said:
By "internal libraries folder" I assume you mean the Libraries folder under Basic4android where the current BLE2.jar was located.

and where the core.jar are located, yes.

The INTERNAL is the Libraries folder in b4a program path
The Additional Libraries folder is the one you setup in b4a Paths.

Turbo3 · Dec 20, 2015

No luck. I can see the adapter light flash indicating it has received the command from the WriteData but I never get a response back.

If I switch back to the adapter that works it continues to work for both the 1 and 2 settings for SetWriteType. I expected it to fail with the 1 settings of no response. So that makes me think the 1 settings is not actually working.

Can you add a debug message when you execute the WriteData that says which type it is actually using?

Erel · Dec 21, 2015

Turbo3 said:
Can you add a debug message when you execute the WriteData that says which type it is actually using?

The library calls the only write API available. It is different than in iOS.

Turbo3 · Dec 21, 2015

Then just a log message that the WriteType has been changed by this new "SetWriteType".

What else could be stopping the response from one adapter and not the other? Both adapters work fine in B4i.

Erel · Dec 21, 2015

Turbo3 said:
Then just a log message that the WriteType has been changed by this new "SetWriteType".

B4X:

log(chrc.RunMethod("getWriteType", Null))

Turbo3 said:
What else could be stopping the response from one adapter and not the other? Both adapters work fine in B4i.

Hard to say. The first step is to try to check it with a different Android device.

Turbo3 · Dec 21, 2015

Just checked with two different Android devices. Same problem. One running 4.4.2 the other Fire OS 4.5.5

One adapter (LELink) works for both Type 1 or Type 2.

The other (Vgate iCar 3) flashes when sent a command but I never get any data back. Both a Type 1 or 2 setting fails.

So the SetType makes no difference on Android but it does on iOS.

KY Leng · Dec 30, 2015

KY Leng said:
Good evening Erel,

In the previous version of BleExtEx (version: 1.10), we can read/write data (serial data from/to BLE device) by using

'Read:
Sub Manager_CharacteristicChanged (Characteristic As BleCharacteristic)
Dim StrIn As String
StrIn = Characteristic.GetStringValue(0)
Log(" RxD <" & StrIn & ">")
End Sub

'Wite:
cwrite.SetStringValue(StrOutBT)
Manager.WriteCharacteristic(cwrite)

With this new BLE2 (version: 1.10), could you please tell us how to do it?
Note: The reason I move from BleExtEx to BLE2 is that BleExtEx could not allow Nexus Android Version 6.0.1 to find BLE device.
And it seem that all Android Version 6.0.1 could not find BLE device with EleExtEx library.

Looking forward to hearing from you soon...

Now I can solve my problem by using BLE2 instead of BluetoothAdmin to scan BLE device. And use BleExtEx to send/read data to/from BLE device (HM-10). Data that I mentioned here is the same serial data that we send using Serial library with Bluetooth 2 device (HC-05).

However, I want to know if BLE2 can do the same (send/read data to/from HM-10 with TxD/RxD pin) with BLE device as Serial do with BT2 device or not ? With BleExtEx, we can do but with limited byte per frame (maybe 20 byte max).

Erel · Dec 30, 2015

I'm not familiar with BleExtEx implementation. BLE (the protocol) doesn't support streaming. BLE2 library exposes all the relevant APIs. You can read and write to the BLE peripheral.

stari · Dec 30, 2015

KY Leng said:
Now I can solve my problem by using BLE2 instead of BluetoothAdmin to scan BLE device. And use BleExtEx to send/read data to/from BLE device (HM-10). Data that I mentioned here is the same serial data that we send using Serial library with Bluetooth 2 device (HC-05).

However, I want to know if BLE2 can do the same (send/read data to/from HM-10 with TxD/RxD pin) with BLE device as Serial do with BT2 device or not ? With BleExtEx, we can do but with limited byte per frame (maybe 20 byte max).

Hi,
i also work with HM-10 and i can send/receive data. On other side i have connected PIC P18F45K22 and also without any problem.
I'ts true, 24 bytes per frame is max.

postasat · Dec 30, 2015

Hi,
I need to extract data from polar H7 heart rate monitor.

I need Heart rate measurement and battery level.

I found some code (from polar) for ios here:
http://developer.polar.com/wiki/H6_and_H7_Heart_rate_sensors

Somebody knows how to get this two type of data ?

Thank you.

Erel · Dec 31, 2015

You should start a new thread for this.

Erel · Jan 7, 2016

Several updates were made in the last two days to the BLE2 library.

BLE is an important feature. Please post any issue you encounter.

B4A Library [B4X] BLE 2 - Bluetooth Low Energy

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