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RS232 find the right configuration

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priestnot

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I have a device with a microcontroller which has a serial port.
I connected this serial port to my PC and i see that wen i turn it on it sends data trough.

But i have a problem i do not know the serial port configuration. (Baudrate, stop bit, etc)

I have tried thsi configuration:
Parity: none
Bits: 8
Stop bits: 1
Flow control: none
Baud rates: 300, 600, 1200, 2400, 4800. 9600, 19200, 38400, 57600, 115200

And it shows me trash (non readable characters)

Is there a way to find the correct configuration without having to do it by brute force?

I am on linux with gtkterm
 

You can use a scope to examine the pulse train and calculate the BAUD rate and other settings.

What type of device is it? Have you attempted to find the manual or datasheet?

BigDog
 

I do not have a oscilloscope. The device is a thinclient based on linux that I am trying to get to the console to see if i can run my own programs in it.
**broken link removed**
 
Last edited:

No i do not think so because it only has pins for RX, TX, GND and 3.3V
 

priestnot said:
No i do not think so because it only has pins for RX, TX, GND and 3.3V
Click to expand...

Ok. By the way, how do you know the pinout, User Manual?

What is the model of the thin client?

Have you connect the GND of the thin client to the GND of the PC?

BigDog
 

No i just open the case and check the Circuit board
The model is IN-A02 from INCTEL. **broken link removed**
 

Successful RS-232 requires the minimum of three connection TX. RX and GND.

So did you connect the GNDs between the thin client and the PC?

BigDog
 

INCTEL IN-A02 thin clients usb, 30 users, support printer

IN-A02 Key Points,

•NCT-XP-2000 multi-user software
•Up to 30 users
•With USB port for printer and flash drive
•PS/2 mouse, keyboard
•100 Mb/s switched Ethernet connection
•640x480, 800x600, 1024x768 (at 60 or 75 Hz refresh rate), 1280x1024 (~63 Hz)
•16 bit
•Supports USB 1.1 memory devices– requires Windows OS on host
•30 users* when using a server host OS (i.e. Windows Server 2003)
•10 users when using a desktop OS (i.e. Windows XP)
•Supported OS
•Microsoft: Windows XP Professional and Media Center Edition 2005
•Windows Server 2003, Small Business Server 2003
•Linux: several variants (refer to support section of Website for latest supported revisions of Linux)
•Support windows XP SP3 patch (Cannot support KB956572)
•NOT support 3D games or full screen home theater video applications
•Kits
•Access terminal, power supply, software installation & user’s guide in CD, mounting bracket to the back of each LCD

Can`t see any RS-232 port

**broken link removed**
 

I finally took at an online manual for the IN-A02:

Ports: 1 usb port;

1 vga port;

1 rj45 port;

1 spk port;

1 ps/2 keyboard port;

1 ps/2 mouse port;

No RS-232 ports listed.

The good news is the unit uses an ARM 926EJ 533MHz 64MB and is compatible with both Windows CE and Linux Distros.

There is most likely a JTAG port located internally for upgrading the system, or some other means.

BigDog
 

They do not announce it I am trying by my self you can consider it a hack i think...

I connected the RS232 (TX, RX, GND)of the PC to a max232 then i connected the max232 to the board of the thin-client (TX, RX, GND) i checked the connections. Thy are correct. The only thing i did out of the ordinary was using a 10K/15K resistive divider to get the 3.3 from the TX of the MAX232 That is connecter to the RX of the micro.

I just want to know if there is a easier way to find the serial configuration without having to go trough all the modes possible.

---------- Post added at 21:50 ---------- Previous post was at 21:47 ----------

As for another connectors, yes there are but it has more then TCK, TMS, TDI and TDO, actually a lot more. I am at home now so i cannot tell how many more.
 

priestnot said:
They do not announce it I am trying by my self you can consider it a hack i think...

I connected the RS232 (TX, RX, GND)of the PC to a max232 then i connected the max232 to the board of the thin-client (TX, RX, GND) i checked the connections. Thy are correct. The only thing i did out of the ordinary was using a 10K/15K resistive divider to get the 3.3 from the TX of the MAX232 That is connecter to the RX of the micro.

I just want to know if there is a easier way to find the serial configuration without having to go trough all the modes possible.
Click to expand...

It is hard to say, especially without a scope, logic or protocol analyzer. It maybe a maintenance port or it might not.



priestnot said:
As for another connectors, yes there are but it has more then TCK, TMS, TDI and TDO, actually a lot more. I am at home now so i cannot tell how many more.
Click to expand...

Most ARM JTAG connectors are 20-pin, with 14-pin being the 2nd most common.

BigDog
 

How can i know pin position in the connector?
Is there some information about how to insert linux on that arm cpu using jtag?
 

priestnot said:
How can i know pin position in the connector?
Is there some information about how to insert linux on that arm cpu using jtag?
Click to expand...

You need to obtain an ARM-JTAG device. Is the connector 20-pin, 14-pin or something else?

The JTAG connectors are usually 0.1" centers, although some manufactures use a custom micro version.

ARM-JTAG DONGLE FOR PROGRAMMING AND DEBUGGING (MACRAIGOR WIGGLER COMPATIBLE)

ARM-JTAG-EW HIGH SPEED ARM USB JTAG WITH TARGET POWER CONSUMPTION MONITORING AND EXTERNAL HARDWARE BREAKPOINT TRIGGERS

I have both a Segger J-Link and a KEIL ULINK2, they are quite expensive for the commercial versions.

However Segger has the same J-LINK offered for noncommercial applications at a great price:

J-LINK EDU

There are adapters available for the 14-pin and other custom connectors.

BigDog
 

Thanks and what about the linux part? How can i put in it a linux distro?
 

The Linux distro depends on the actual ARM variant you have in the device. It supposedly has an ARM 926EJ 533MHz, report back the actual part number on the ARM and I will recommend some possible options.

Also let me know the JTAG connector type, pin count, style, etc.

BigDog
 
Thanks i will be back on monday with that info..
 

Ok Now i have the information you need. At least the one I can get here are some photos of the system:
IMG18.05.35_02-01-2012.jpg IMG18.03.14_02-01-2012.jpg IMG18.03.04_02-01-2012.jpg IMG18.02.52_02-01-2012.jpg

And here is a photo of my max232 with a voltage divider on the RX of the micro to get from 5V to 3.3V
IMG18.05.52_02-01-2012.jpg

As you can see in the photos i cannot tell the microcontroller because it has no marks (they removed them) The rest of the main chips are there in the photos.
Samsung 710 memory
hynix 742E Ram
Spansion 112FF377 I think

I think that it has a JTAG connector with 14 pins
 

Have you attached a monitor, keyboard and mouse to the unit and booted it? You maybe able to obtain some information regarding the processor from either the boot process, setup configure mode or the OS installed (Windows CE?).

Also the 14-pin connector pin holes appear to have three attached wires what are they and what pin numbers are they attached?

BigDog
 

I did connect it to a monitor it just boots the software of the thinclient. I know by the manufacture that the OS is linux.
The 3 wires are mine they are connected to the RX, TX, GND of the uart. The jtag does not have any writings and i did not connect any thing to it.

Sorry I know that this is less information then expected but that is all I got.
 

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