DevHeads IoT Integration Server•17mo ago

Writing Values Greater Than 0xFF to OCR1A in AVR C Code: How?

Hello, is anyone here ??

Solution

you need to ensure that both the high and low bytes are correctly written to

OCR1AH

OCR1AH

OCR1AH

OCR1AH and

OCR1AL

OCR1AL

OCR1AL

OCR1AL. Here’s how you can do it:

OCR1AH = (0x3344 >> 8); // High byte
OCR1AL = (0x3344 & 0xFF); // Low byte

OCR1AH = (0x3344 >> 8); // High byte
OCR1AL = (0x3344 & 0xFF); // Low byte

OCR1AH = (0x3344 >> 8); // High byte
OCR1AL = (0x3344 & 0xFF); // Low byte

OCR1AH = (0x3344 >> 8); // High byte
OCR1AL = (0x3344 & 0xFF); // Low byte

This should work in IDE 18.1.9 as well.

Jump to solution

Camila_99$$APP•8/29/24, 2:09 PM

Can anyone tell me if any of you have successfully written a value greater than 0xFF into OCR1A, and if so, how?

Personally, I do it in assembly using AVR STUDIO 7, and my tests show that values such as 0x3344, for example, are correctly handled, and TCNT1 counts up to this value before toggling the corresponding output (OC1A).
However, under IDE 18.1.9, there's no way to directly write such a value in C. Even when incorporating my assembly code into C, the compilation goes fine, but OCR1H always remains at zero.

Does anyone have a solution?

Solution

wafa_athAPP•8/29/24, 2:22 PM

you need to ensure that both the high and low bytes are correctly written to

OCR1AH

OCR1AH

and

OCR1AL

OCR1AL

. Here’s how you can do it:

OCR1AH = (0x3344 >> 8); // High byte
OCR1AL = (0x3344 & 0xFF); // Low byte

OCR1AH = (0x3344 >> 8); // High byte
OCR1AL = (0x3344 & 0xFF); // Low byte

This should work in IDE 18.1.9 as well.

Camila_99$$APP•8/30/24, 6:40 PM

Thanks so much for the tip!
I didn’t think of splitting the high and low bytes like that. I’ll try it out in IDE 18.1.9 and see if it works

Writing Values Greater Than 0xFF to OCR1A in AVR C Code: How?

Similar Threads

Similar Threads

Similar Threads