LPC2148 Serial output Trouble

capablazab wrote on Friday, September 14, 2012:

Dear friends,

I have an LPC2148 with FreeRTOS v7.2 (ported from lpc2106 GCC example). The LEDs blink ok.

The problems come when I see the serial port output which is:

\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03’\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x1b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03’7#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x1b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x1b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb\0x03\0x13\0x1b#+3;\0xc3\0xcb\0xd3\0xdb\0xe3\0xeb\0xf3\0xfb\0x03+\0xcb\0xeb\0x0b++,;\0x0b\0xfb
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I’m using cutecom with 115200 bauds, 8 data bits, 1 stop bit, no handshake.

I would appreciate if anyone could give me a hand with this.

Cheers!

capablazab wrote on Friday, September 14, 2012:

I forgot to mention that I’m working under ubuntu 12.04.

The code was compiled using arm-none-eabi-gcc

davedoors wrote on Friday, September 14, 2012:

What should the serial port output be?

What you post looks like a load of escape characters so it might be that your terminal is not set to show raw ASCII characters.

Most demos use a loopback com port test. If you loop the characters back to the receive on the LPC are they received as expected?

capablazab wrote on Friday, September 14, 2012:

Thank you for your fast response!

I managed to get it working.

I forgot to change the cpu frequency: I ported the Demo code from an LPC2106 which  has a 14.7456MHz clock. My lpc h2148 has 12 Mhz clock. Changing that solved the problem and now I can see the serial port output!

Now cutecom prints

ABCDEFGHIJKLMNOPQRSTUVWX

repeatedly.

In case some one doesnt know, the file that has to be changed is: (in FreeRTOSConfig.h)

#define configCPU_CLOCK_HZ              ( ( unsigned long ) 48000000 )   // 48000000 Hz for the lpc h2148

Thank you anyway for your support