Changes

This How-To is meant to be a starting point for people to learn use UART for IGEPv2 IGEP devices as quickly and easily as possible. In this howHow-toTo, we use [http://labs.isee.biz/index.php/Pre-installed_software_on_IGEP_Processor_Boards IGEP Firmware]and a program that use UART peripherals. More information about This How-To was tested in: *[http://en[IGEP firmware Yocto|IGEP firmware Yocto]] and [[Linux_Kernel_2.6.37.y|Kernel 2.6.wikipedia37.org/wiki/UART UARTy]]with IGEPv2.

'''Note''': Example program used has a debug option using GPIOs to debug via oscilloscope, this option method is useful to learnt learn about the Kernel latencies. Debug has set to "write" and "select" functions. [[Frequently Asked Questions and Their AnswersPeripherals Summary#How_many_UARTs_are_available.3FUART|More information]].

= Feedback and Contributing Preparing IGEP =IGEP Uart devices have the following names in Kernel [[Linux Kernel 2.6.35.y|2.6.35.y]]:*UART1: /dev/ttyS0*UART2: /dev/ttyS1*UART3: /dev/ttyS2*UART4: /dev/ttyS3IGEP Uart devices have the following names in Kernel [[Linux Kernel 2.6.37.y|2.6.37.y]]:*UART1: /dev/ttyO0*UART2: /dev/ttyO1*UART3: /dev/ttyO2*UART4: /dev/ttyO3

= Preparing == Configure UART1 and UART3 in IGEP with RS232 levels on J960 connector ===

=== Configure UART1 and UART3 in IGEP with RS232 levels on J960 connector = Edit igep.ini file ====

NOTE: Make sure that you installed open SSH server. If you don't have it go [[How to forge a local file system server with IGEP0020 board#Installing_Open_SSH_Server|here]].  By default, *UART1 is can used by RS485 driver, we need to disable it, edit igep.ini file: <br> <pre>board.ei485= yes</pre> *UART1 is configured in RS232 driver, when igep line is replaced by (or type in -Maybe you don't found this line-):<br> <pre>board.ei485= no</pre> *By default, UART3 is used by Kernel serial console, we need to disable it, go to igep.ini file, comment next line: <br>

Use minicom microcom to prove it, open two terminals via SSH and log with root user:

Type something in one terminal.  {| cellspacing="1" cellpadding="1" width="200" border="1" align="center"|-| style="text-align: left;" | [[Image:Minicom screenshot.png|640x400px]]|}

Download [http://labs.isee.biz/images/e/eeindex.php/File:Uart-test-beta22-beta1.tar.bz2 program source]and extract it.  As explained above, Before compiling the program uses GPIO for debug option via oscilloscope, it is necessary install user-gpio-drv.ko driver inside Linux Kernel, more information [[How to use GPIOs|here]] .  There there are some interesting things to configure, before compiling the program. Open it, program and seek next lines:

#define GPIO1 136158#define GPIO2 137 162</pre> Constant SIZE: it determines the max number of char than chars sended. Constant DEBUG: it can be sent<br> break program infinite loop part, useful to debug errors: 0 (infinite loop) or positive number determines loop max entrances.

Constant DEBUGWAIT: it can break program infinite loop part, it can be useful to debug some errors, 0 (infinite loop) or positive number determine loop configures select max entrances time in seconds.

Constant WAITConstants GPIO1 and GPIO2: it configurea select max timethey configure GPIOs used for debug via oscilloscope. By default, 158 and 162 values are not used in IGEPv2. Configure [[Mux configuration|mux]] properly if you use other GPIOs.

Constants GPIO1 and GPIO2Compile source code using a [[How to setup a cross compiler|cross compiler]] for example IGEP SDK: they configure GPIOs used for debug via oscilloscope<pre>arm-poky-linux-gnueabi-gcc uart-test-2-beta1. Take care to configure mux and don't use them for other purposesc -o uart-test-beta1 <br/pre>