B4A Library Open/Read/Write - UART Serial device

qle · Sep 18, 2012

I need to open/read/write a serial (UART) device - "/dev/eser0"
(a laser scanner)

Im unsure if b4a can do this, or if th IOIO lib can achieve this?

I do have a "libserial_port.so" but am unsure how it can be used in b4a.
Ive spent the day searching and reading the forum, but im none the wiser!

Best Regards
Lee

Erel · Nov 4, 2013

Most devices do not have a built-in serial port. This is not part of a standard Android device.

Ferraz71 · Apr 25, 2014

this library just work in devices where the serial port is unlocked like in the mxt models, where is not necessary an external driver.

Ferraz71 · Apr 25, 2014

DrewG said:
Thank you for this, it works on a Boundary Devices iMX6 N6x board on the ttymxc0 hardware serial port.

Only thing to note is that you need to use flag '2' and not flag '0' if you want read and write access to the port, with flag '0' I could only read.

it depends your device model, in my case my imx device can read and write using the flag set to zero

mrodriguez · Apr 26, 2014

Hi, I'm using the usblibrary that supports FTDI chip but the problem is that this library doesn't supports 2 FTDI chip on the same android.
Can I use this library instead usblibrary?
Does it work with FTDI chip?
I need UART instead RS232 signal, what adapter do you recommend me?

I need to connect 2 uart device to my android to send serial command.
I have tried usblibrary+FTDI chip and IOIO board. It is a good solution for connecting 1 serial device.
Thanks

EvgenyB4A · Sep 14, 2014

Ferraz71 said:
Benji..

use
.........................................
Dim c As PortFinder
Dim d As SerialPort
Dim x As AsyncStreams
.........................................

c.AllDevicespath.Length //(number of devices)
c.AllDevicespath// (device path list)
d.SetPort("string adress",int baud rate, byte flags) //set serial port..
x.Initialize(d.InputStream,d.OutputStream,"Astream ") // connect with asyncstream

where Astream is a function that receive the input buffer
likes this:
Sub Astream_NewData (Buffer() As Byte)
your commands here
end sub

and for write to the port use

x.write(buffer) 'where buffer is a byte array

or

x.write2(buffer,initial byte, lenght) 'to write some bytes inside buffer array

Hi
I try to use your library. I can send from Android device to PC the strings, but can't receive from PC.
And the second problem is that the program is stacked on the line d.SetPort... in debugger very often. It is need to turn off and turn on the device.

jinyistudio · Mar 12, 2015

Hi

Would you tell me how to using the parameter flags of the function setport ? 0 is what ? 2 is what ,,,,,,,

jinyistudio · Mar 12, 2015

B4X:

.........................................
Dim c As PortFinder
Dim d As SerialPort
Dim x As AsyncStreams
.........................................
Label1.text=c.AllDevicespath.Length //(number of devices)
Spinner1.AddAll(c.AllDevicespath)// (device path list)
d.SetPort("/dev/ttymxc0",9600,0) //set serial port..
x.Initialize(d.InputStream,d.OutputStream,"Astream") // connect with asyncstream

Hi

How did i know d.setPort Ok or NG ? Because d hasn't IsInitialized !

vdudukov · Jun 22, 2015

Hi

I have laser barcode scanner with uart port. My virtual folder is /dev/ttyMT2.

I tried to connect it with:

B4X:

Dim d As SerialPort
Dim x As AsyncStreams

d.SetPort("/dev/ttyMT2",9600,0)
x.Initialize(d.InputStream,d.OutputStream,"Astream")

Sub  Astream_NewData (Buffer() As Byte)
Dim msg As String
msg = BytesToString(Buffer, 0, Buffer.Length, "UTF8")
Log(msg)
End Sub

But with no success :-(

Everytime i must initialize port, or set TIMER.

I downloaded serial port app from GooglePlay, and everything works fine.

How can i do it with B4A ?

Erel · Jun 22, 2015

Do you see any error message?

jinyistudio · Jun 22, 2015

Do you have read/write right for "/dev/ttyMT2" ? chmod 777 /dev/ttyMT2

vdudukov · Jun 25, 2015

Erel said:
Do you see any error message?

No, i do not see any message. Just when i create timer, and everytime tick, message from ttyMT2 file came to log. In this case EAN Code.

Sub timer1_Tick
d.SetPort("/dev/ttyMT2",9600,0)
x.Initialize(d.InputStream,d.OutputStream,"Astream")
End Sub

jinyistudio said:
Do you have read/write right for "/dev/ttyMT2" ? chmod 777 /dev/ttyMT2

I put chmod 777, but then i got message java.io.IOException

jarda · Jun 29, 2015

Ferraz71 said:
Hi.... :sign0060::sign0060::sign0060:

Erel,

i did make a small change in the serial_port_api and now i can list, read and write in all serial devices in my tablet ( in my case... the port /dev/ttymxc0 is unblocked). with this library now i can set the baudrate, port adress and flags in all devices.

there are two types created. "PortFinder" and "SerialPort"

.........................................
Dim c As PortFinder
Dim d As SerialPort
Dim x As AsyncStreams
.........................................

Label1.text=c.AllDevicespath.Length //(number of devices)
Spinner1.AddAll(c.AllDevicespath)// (device path list)
d.SetPort("/dev/ttymxc0",9600,0) //set serial port..
x.Initialize(d.InputStream,d.OutputStream,"Astream") // connect with asyncstream

this is the compiled library with the. jar and .xml... for android 2.3 and higher
enjoy it!!

thanks a lot for your help...i am very very happy with de b4a.

Hi

We downloaded a library UART.

Unfortunately for me B4A ver 4.3 fails Declaration (Android 4.0.4)

e.g.
dim ser as serialport

when you start (on HW with 2xUART) getting the message

"Unfortunat App has stopped"

--------------------------- code
Sub Process_Globals
'These global variables will be declared once when the application starts.
'These variables can be accessed from all modules.
End Sub

Sub Globals
'These global variables will be redeclared each time the activity is created.
'These variables can only be accessed from this module.

Dim ser As SerialPort

End Sub

Sub Activity_Create(FirstTime AsBoolean)
'Do not forget to load the layout file created with the visual designer. For example:
'Activity.LoadLayout("Layout1")
End Sub

Sub Activity_Resume
End Sub

Sub Activity_Pause (UserClosed AsBoolean)
End Sub

Jarek

------------- Log
Installing file.
** Activity (main) Pause, UserClosed = false **
PackageAdded: package:b4a.example
main_globals (java line: 401)
java.lang.NoSuchMethodError: android_serialport_api.SerialPort.<init>
at b4a.example.main._globals(main.java:401)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:187)
at b4a.example.main.initializeGlobals(main.java:306)
at b4a.example.main.afterFirstLayout(main.java:97)
at b4a.example.main.access$100(main.java:17)
at b4a.example.main$WaitForLayout.run(main.java:78)
at android.os.Handler.handleCallback(Handler.java:605)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
** Activity (main) Resume **

vdudukov · Jul 6, 2015

Can somebody reply to my previous post, please.
I am trying to understand where is the problem with my code and serial lib...

Thank You.

vdudukov · Aug 11, 2015

I tried Serial Port Api sample, and it is working very good.
Can we implement this solution in b4a?

vincentehsu · Oct 13, 2016

Sirs:

I wanna communcate with SPI interface via USB OTG
When i try to use

B4X:

d.SetPort("/dev/ttyUSB0",9600,0)

i get the errors

B4X:

java.io.IOException
    at android_serialport_api.SerialPort.SetPort(SerialPort.java:72)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.shell.Shell.runVoidMethod(Shell.java:747)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:342)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:246)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
    at b4a.example1.main.afterFirstLayout(main.java:102)
    at b4a.example1.main.access$000(main.java:17)
    at b4a.example1.main$WaitForLayout.run(main.java:80)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:158)
    at android.app.ActivityThread.main(ActivityThread.java:7237)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

Erel · Oct 13, 2016

Is this the full error message?

Did you connect a USB to serial converter? You can use UsbSerial or felUsbSerial libraries.

androh · May 31, 2018

B4X:

d.SetPort("/dev/ttyUSB0", baudrate, flags)

Is there any detailed documantation about "flags" parameter?

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