OLIMEX power supply

Development Boards MicroMod
1

Hi,

I 'm new here, so maybe this question was already asked.

I’m using Olimex-board LPC-P2138 and programming it with Rowley Cross studio 1.9.

I disconnected ARM-USB-OCD connector and tried to use an external power supply (i just disconnected power supply, not JTAG) but cross studio doesn’t recognise the target. Even when i download program to target and then connect an external power supply, ther program doesn’ work. Where can be the problem?How to use an external power supply?

Thanks for answers!

2

One of the things you need to do in Rowley to allow power up & reset is to do the following.

STARTUP_FROM_RESET has not been defined when assembling the startup code.

Some versions of the ARM startup code won’t start up the application from reset by

default, this is to workaround problems with the ARM reset by allowing the debugger to

reset the CPU and run programs from a known reset CPU state on each run. Not

allowing the application to startup from reset also acts as a safety net if you accidently

download a program in FLASH that crashes and prevents the debugger from taking

control over JTAG rendering the target unusable over JTAG. To define

STARTUP_FROM_RESET select the startup code in the the project explorer, right

click, select Properties and then add STARTUP_FROM_RESET to the Preprocessor

Preprocessor Definitions project property.

3

Yes, I already did that and the program starts normally when i press the reset button.

But when i disconnect ARM-USB-OCD connector from PC and then connect it again,the program doesn’t start, even i downloaded it in FLASH.

Where can be the problem?

4

give me a link to the board your using.

5

LPC-P2138: http://www.olimex.com/dev/lpc-p2138.html

6

" ARM-USB-OCD connector " you mean JTAG connector.

that is normal, as when you remove the connector and re-instert it, it resets it.

if you do plug it in while it running just go to Target, disconnect & then reconnect. in the Rowley menu.

7

It’s a good idea to connect the JTAG before powering the board, and to remove it only when the board isn’t powered. The ARM chip can be damaged if the correct sequence isn’t observed. It’s unlikely, but I have known it happen.

Leon