Can someone tell me why this code doesnt do its job? I am new to uVision. The code should turn on the LED diodes as you turn the potentiometer. For example, if its on position 0V the first LED should be lit, and if its on position 3.3V the last one. Tnx in advance
#include <stdio.h> #include <stdlib.h> #include <LPC214x.h>
void delay(int i){ unsigned int j; for(j=0; j < i; j++); }
int main (void) { unsigned int rez; IODIR1 = 0x00FF0000; //diode postavljene kao output AD0CR = 0x00200402; //ADC1: 10-bit AIN1 @ 3MHz
while(1){ AD0CR |= 0x01000000; // start AD konverzije
while ((AD0DR1 & 0x80000000) == 0); // cekanje da se konverzija zavrsi
AD0CR &= ~0x01000000; //stop AD konverzije rez = AD0DR1 & 0x0000FFC0; if(rez < 128) IOSET1 = 1 << 16; else if(rez > 128 && rez < 256) IOSET1 = 1 << 17; else if(rez > 256 && rez < 256+128) IOSET1 = 1 << 18; else if(rez > 256+128 && rez < 512) IOSET1 = 1 << 18; else if(rez > 512 && rez < 512+128) IOSET1 = 1 << 19; else if(rez > 512+128 && rez < 768) IOSET1 = 1 << 20; else if(rez > 768 && rez < 768+128) IOSET1 = 1 << 21; else if(rez > 896 && rez < 1024) IOSET1 = 1 << 22; else IOSET1 = 1 << 23;
delay(100000); }
}
"But another thing - have you switched the input pin from digital function to analog function? I don't see you assign anything to any PINSELx register."
I dont understand this. The AD0CR controls which channel are you using (the value 0x02 setts this to AIN1). And AIN1 is connected to the potentiometer trough a jumper, so you dont have to initialize the input. Its already connected as default. If you want to take a look here is the schematic http://www.keil.com/mcb2140/mcb2140-schematics.pdf (go to second page)
Did you spend time with the manual, reading about the PINSELx registers?
Dod you read through the full chapter about the ADC in the user manual?
Did you specifically read the information in the paragraph 19.5.3 Accuracy vs. digital receiver?
The NXP user manual is the #1 document to read through when using the processor.
As I said earlier, I don't work with any LPC21xx chips. So I don't have a reason to invest the time to read up on all the details. I spend my time reading the documentation for the processors I use.
But you have a big reason to invest the time with the LPC214x user manual. www.nxp.com/.../UM10139.pdf
It worked, even tough I dont quite get it. I add this code
PINSEL1 = 0x01080000; // Select DAC (AOUT) & AIN1
to the source. Btw, I did read the manual many times... Tnx for your help, both!