Re: Aux I/O not responding

On 8/2/2013 10:07 AM, Taiwo wrote:
> Hello guys
>
> I'm quite new to the Rabbit MCU. I have been trying to send some
> messages to an OLED through the aux I/O pins, but none of the pins
> associated with the Aux I/O are responsding (including /IORD and /IOWR).
> I have macro definition at the start of the source file, amongst others.
> Please what am I missing out in the source file.
>
>   Below is a brief description of my file.
>
>
>
> #define PORTA_AUX_IO // Enable the external I/O bus
>
> void SendToOLED(int addr, char value)
> {
>    WrPortE(addr, NULL, value);
> }
>
>
> int main()
> {
>     WrPortI(IB7CR, &IB7CRShadow, 0x4C);  // Invert
>
> // Ensure tht the 6-bit address external I/O bus is enabled
>     MsDelay(1000);        // Wait for one second to allow OLED to reset
> itself
>
>     SendToOLED(1, '\B00111001'); // 8-bit, 2 line, 5x8 dots, Western
> European font
>     SendToOLED(1, '\B00001100'); // Display On, Cursor Off, Non-Blinking
> cursor
>     SendToOLED(1, '\B00000110'); // Increment and Non-shift Entire
> Display
> }

The address for the external I/O is:

PE0 - 0000-1FFF
PE1 - 2000-3FFF
... and so on...
PE6 - C000-DFFF
PE7 - E000-FFFF

So try:

void SendToOLED(int addr, char value)
{
   WrPortE(addr+0xE000, NULL, value);
}


You will probably need to add checks to make sure the display is ready
to write to. Add a check for the ready bit in the display status
register before writing or you could just add delays if you can't read
the display.

<Scott>



-- 
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     Scott G. Henion, Consultant
Web site:    http://SHDesigns.org
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