B4J Library jSerial library

The jSerial library allows you to open and communicate with other devices through the computer COM ports.

It can also be used to communicate with Bluetooth devices over a virtual com port.
(jBluetooth library is now available: https://www.b4x.com/android/forum/threads/jbluetooth-library.60184/)

The attached examples implement an Android <-> PC chat app.

In order to run the example you need to first pair the PC and the device and make sure that the Bluetooth is mapped to a virtual com port.

jSerial works with AsyncStreams. Both standard mode and prefix mode are supported. Note that prefix mode can only work if both sides of the connection follow the protocol.
Change AStream.InitializePrefix to AStream.Initialize to disable prefix mode.

jSerial depends on an open source project named JSSC: https://github.com/java-native/jssc

Updates:
v1.40 - Based on jssc v2.9.6. Provides better handling of low level errors. Edit: a new zip was uploaded which fixes an issue with the standalone packager.
v1.32 - Based on jssc v2.9.4.
v1.31 - Adds missing BAUDRATE, DATABITS, STOPBITS and PARITY constants.
v1.30 - Adds support for Java 11 and 64 bit computers based on: https://github.com/java-native/jssc

Instructions related to jSerial and B4J Packager 11: https://www.b4x.com/android/forum/threads/jserial-library.34762/post-735742

 

[Erel]

This error happens in the native layer. It is possible that the native library is not fully compatible with Raspberry Pi.

Have you tried to change the parameters? Is this port listed when you call ListPorts?

Have you tried it without the PurgePort call?

 

[rdkartono]

Hi Erel,

Set Parameter already correct (4800 bps, 8 bit, 1 stop bit, None parity), because i already can read GPS string correctly. I can get correct Time, Longitude, and Latitude string. This port (/dev/ttyAMA0) is the result from "dmesg | grep tty".
I tried calling GPS_PORT.PurgePort(GPS_PORT.PURGE_RXCLEAR) everytime AsyncStreams.New_Data event triggered (after i get the data), yet still after few seconds std::bad_alloc still showed.
I tried polling to serialport bytesavailable value using a timer with interval 1 ms, yet bytesavailable always return 0.
I tried to wrap serial port inputstream to TextReader, yet also no data available.

It seems that AsyncStreams.New_Data event is the only way to get serial data, yet it is unstable.

Please advice more.
Thanks.

 

[Erel]

The problem is not in AsyncStreams. It is in the native driver that jSerial library wraps.

 

[rdkartono]

Hi Erel,

Can I do polling inputstream like old fashioned style?

 

[Erel]

Yes. You can read directly from the input stream.

 

[rdkartono]

Hi Erel,

I just want to let you know, that the problem is solved. Followed this tutorial (http://www.hobbytronics.co.uk/raspberry-pi-serial-port), disable serial console, and its good now using standard Asyncstream class.

Regards,

Rudy.

 

[a_carignan]

I can not connect the two software together. on the phone, it displays an error connecting to the computer and it shows no wear.

 

[Erel]

Were you able to pair the phone to the PC? Have you configured the PC virtual com port?

 

[alexhi]

How can I open a port in MAC OS?

 

[Erel]

The same code should work. Do you get any error message?

 

[alexhi]

sp.Open(cmbPort.Value) Works in Windows but does not work Mac OS , in Mac OS X 10.9 receives NULL

 

[Erel]

Is there any message in the logs? Are you sure that you are opening the correct port?

 

[wonder]

I need help!

I did everything right, paired my phone with the PC. Added a COM port and tried to connect.
When I choose my PC name, I get a pairing request on my phone, which after one second disappears and I get a "connection reset by peer" java.io error.
I've tried the prefix and standard mode, recompiling both B4A and B4A apps. HELP!

 

[Erel]

If it happens before you send any message then the problem is in a lower level.

 

[Erel]

jSerial was updated with the latest version of jssc (2.8.0). The jSerial version is the same as before.

 

[SimonElck]

The jSerial library allows you to open and communicate with other devices through the computer COM ports.

It can also be used to communicate with Bluetooth devices over a virtual com port.
(jBluetooth library is now available: https://www.b4x.com/android/forum/threads/jbluetooth-library.60184/)

The attached examples implement an Android <-> PC chat app.

In order to run the example you need to first pair the PC and the device and make sure that the Bluetooth is mapped to a virtual com port.

jSerial works with AsyncStreams. Both standard mode and prefix mode are supported. Note that prefix mode can only work if both sides of the connection follow the protocol.
Change AStream.InitializePrefix to AStream.Initialize to disable prefix mode.

jSerial depends on an open source project named JSSC: http://code.google.com/p/java-simple-serial-connector/ (the jar file is included in the zip file).

I compiled this program an ran it.
It works fine, BUT
as soon as I make an installable version with packager, it does not work anymore.
It quits at the line sp.Open(cmbPort.Value)
Even when I put it in a try /catch it quits
Again the prog works fine when I run it, either debug or release.
It has nothing to do with readonly files either.

Please help, I'm stuck!

 

[Erel]

Find the jar file in the installation folder and run it from the command line with:
java -jar <your jar>

 

[SimonElck]

Thanks Erel,
It's going to be a bit awkward for my users.
Will the packager installed Java still be sufficient when going this way, or will the end-users have to install jre or something?

 

[Erel]

It is not for the users. By running it from the command line you will be able to see the logs.

 

[SimonElck]

It is not for the users. By running it from the command line you will be able to see the logs.

Oh, OK, sorry I didn't get that.
I will try this.