Hi Guys,

First time poster/noob,

Ive got a PSoC 1 eval kit and I am generally used to the MSP430 but I started using PSoC programs,

I was just wondering how to use the _Read() and _Write() API's correctly.

I have an LED on Port1.0 and normally I would use the following to set port to High: PRT1DR &= ~0x01;

I changed the name of Port1.0 in the PSoC pinout page to led,

Can i simply just use the following to make the port pin high?

led_write(1);

thanks

 Hi,

The simplest method of controlling an LED is to add a LED usermodule.

From the userdmodule window, expand "Misc Digital", and double click on "LED" to place it.

Use the "parameters" window to set a name to your LED and assign the pin and the active low/high logic. Press Ctrl+F6 to generate the usermodule files.

From your code, you can now use LEDname_On and LEDname_Off to switch your LED on and off (LEDname is the name you give to the usermodule)

Happy coding!

If you perform read modify write operations on a port you need

to use shadow registers -

http://www.cypress.com/?rID=39497

http://www.planetpsoc.com/psoc1-articles-digital/13-basics-of-psoc-gpio.html?start=5

Regards, Dana

Forgot to add, if port has mixed I/O in it.

Regards, Dana.

Using an LED usermodule automatically takes care of the Shadow register issue (if you want a quick intro to what shadow registers are all about, check out the second video on this page - http://www.cypress.com/?rID=2900)

But as per your post, if you want to avoid using a usermodule/shadow registers for some reason and use just the pin name, you can use the following code to control a pin-

led_Data_ADDR |= led_MASK;  

led_Data_ADDR &= (~led_MASK);  

// where "led" is the name you had given in the Pinout window, also check that Drive should be "Strong" for a digital output

The _Data_ADDR and _MASK are MACROS that are generated automatically, when you assign a name to a pin.

Note that advantage of this method is that you can also use for an input pin (configured as High-Z) for a read operation:

pinStatus = inputPin_Data_ADDR & inputPin_MASK;  

Hi Guys,

Thanks for your replies, really appreciate it!

I have an LED on the output at them moment but the output may be used to send a signal to a transistor or otehr devices.

ill have a look through the links sent

thanks again guys

Using the Led user module even if you don't use mixed I/O on the port will save you a lot of trouble. I mean, if eventually you decide to have a pull-up on the next port pin, the shadow register will be automatically updated by using LedName_On(); or LedName_Off();. You won't need to care about read/modify/write issue.