PCA9532 LPCXpresso Base Board

05 Feb 2010

Hi, mbedders.

Now, before you laugh, I'm kinda lost on the I2C topic.
So I bought the Base Board from EA, and wanted to try the PCA9532 LED dimmer expander thingy.
And i thought, that if i used the PCF8574 files, with some editions, it could do the trick. But, somehow this little bastard, keeps giving me errors. Can anyone point out for me, what I am doing wrong?

I really can't see where my error should be:


and here's the datasheet for the IC:



/ Lerche

05 Feb 2010

1. You forgot to rename the class in PCA9532.h

2. PCA9532::write should probably look like this:

char foo[2];
foo[0] = data;
foo[1] = command;

05 Feb 2010

Great, thanks Igor.

It compiles, now I have to figure out why it doesn't turn on my LEDs. :-)

06 Feb 2010

Yes, it's working!!
Got full control of the LED array now.
Will try to make it easier to write to LEDs and setting dim freq and PWM.

06 Feb 2010

cool bananas

21 Mar 2010

I'm a newbee with both the mbed and the LCPExresso base board.

I can't seem to find any basic info, like how to install the mbed (toward the top pin #1 or from the bottom near the SD card).

My hope with these cards is to bypass the wiring to use the mbed as I am physically challenged. I still want to be able to use the mbed toolchain and projects.

Can someout out there steer me to start-up?

Thanks to all.

21 Mar 2010

I have been looking around the website and I have found this : http://mbed.org/users/okano/notebook/lpcxpresso-base-board-i2c-device-operation-example/

Shows how to use the i2c for the LED lights and light sensors

21 Mar 2010

Here is one of my test writeups:


Includes a photo/video, which shows positioning of mbed.


21 Mar 2010


Thats exactly what I was looking for!

There seems to be little info available for using mbed & lpcexpresso together.




21 Mar 2010

Yes, it's really not obvious where the mbed fits on the base board; the DIL headers have extra pins as the LPCXpresso board is bigger. Nonetheless, page 2 of the baseboard schematic diagram shows the connector in detail - Pin 1 of the header (as labelled on the PCB, next to the anti-ESD pictogram) is Pin 1 of the mbed (marked as GND on the mbed PCB, to the left of the USB socket).

Put simply, if the text on the baseboard is the right way up, the USB socket on the mbed should be at the very top of the header, above the little "notch" in the printed rectangle within the header area.

21 Mar 2010

Thanks to all for the help.