LPC2148 I2C and Winarm / need a working example program

Development Boards MicroMod
1

I’m working off the example interrupt style I2C program in the winARM pack. I’ve been trying to get my LPC2148 to talk to a Semtech sx8724 data acquisition chip. I’ve run into an issue that the SDA line posts only 8 1’s an then a 0. I’ve tried turning my clock way down. Poked around with an o-scope, plotted the scl vs sda.

equipment I am using:

Embedded artists quickstart usb board with an LPC 2148. Has a wired eeprom to the i2c bus 3k pull up resistors on the sda/scl lines. I also have the prototype/expansion board for the unit.

Have a dmm and a fluke 196c o-scope (100MHz) good enough for a 400 kHz scl.

Software: I have winarm and eclipse/yagarto. I really only know how to write linker files for winarm. It has done me well so far. GNU make 3.80, gcc 3.1.1 (comes in the winARM bundle works with yagarto).

I have a feeling that the problem is I’m not getting my data to the bus but the interrupt routine is starting everything, just not shifting any data into the I2DAT register. I was wondering if anyone could point me to a I2C program that compiles in Winarm.

The DAQ is connected to a wheatstone bridge style sensor.

The final goal of this project is to be able to:

recieve configuration settings via uart0

program an I2C daq chip,

read the i2c daq chip,

configure analog mux array using gpio (switches inputs to the DAQ)

Calculate snr/noise floor

output data via uart0 (bridge voltages 1-4, snr, noise floor, offset…)

todo

recieving configuration values

collect/convert data

config values algorythm in host computer

realtime plot in host computer

walk in graduation ceremony in t- 1.25 hours

Regards

2

You should find some code in the LPC2000 Yahoo group Files section.

Leon

3

All of the SFE products that use the LPC2148 have code, you could use that for a base.

4

I actually moved to that forum to this one. I’m trying to find an example that does not use RTOS(jcwren) or have any stlib functions(embedded artists) in it. Just pure i2c. I am using the rprintf function to get data/error messages out of the device.

I suppose my main issue is that I moved from the 8051 with a plethora of development tools to an arm to learn something new and its been… a lot.

I’ve spent so much time on this project that I don’t want to switch back now.

I’m just trying to learn the basic functionality of I2C and this arm. I don’t know that I need RTOS.

5

There are several examples there, including some that don’t use an RTOS. I don’t see a problem with the ones that do, anyway; simply use the basic I2C routines and chuck the rest away.

Leon

6

I suppose my main issue is that I moved from the 8051 with a plethora of development tools to an arm to learn something new and its been… a lot.

I’ve spent so much time on this project that I don’t want to switch back now.

Amen to that - for me it’s the issue of having such high quality tools provided for free with Pic16, Pic18, Dspic30, Dspic33, and now Pic32 that I keep having trouble justifying the pain of getting tools for ARM processors to behave.

Granted, I conceptually like the idea of a free open source software environment so it’s not a commercial issue to sell the code I develop, but it hasn’t been a hurdle for my lab so far.

The world needs a standardized, working, open source (is this a contradiction?) platform for arm development.

7

… nothing behaves on a laptop with vista 64 on it…

so many issues

I have learned that my main problem with the I2C sequence is that the interupts weren’t enabled globally. I have been playing around with a program with bits and pieces of a app note from keil. I get the interrupts to work, and it “looks” like it debugs fine through uvision 3 but when I flash the chip it dies when it reaches the isr. I also do not get the SCL signal… though when I was using winarm the scl worked and it sent a repeated start signal it just doesn’t move through the isr at all. I even tried polling the i2c0stat register for 0x08 (i2c start transmitted) to no avail. I could seriously use some help with this. I took this entire week off work to make some headway on my project and I’ve been finking with this i2c problem for the past 3 weeks