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mizzard
Joined: 26 Apr 2009
Posts: 11
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| Problems using dspic33ep256mu806 AN0 and AN1 ADC |
 Posted: Mon Nov 05, 2012 5:19 am |
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Hello everybody, I am going to explain my problem.
I am developing a prototype using dsPIC33EP256MU806, in wich I need to use the 2 analog inputs, AN0 -> RB0 and AN1 -> RB1
I use PCWHD compiler from CCS version 4.128
The problem is that I can not read the correct ADC value (tested using a voltimeter and can see the desired voltage) either in AN0 and AN1.
The dsPIC is working because I use 4 hardware USARTs and I can see debug lines using fprintf.
I attach my first code:
Main.c
| Code: | void main(){
unsigned int16 lectura = 0;
setup_adc_ports(sAN0 | sAN1 | VSS_VDD);
setup_adc(ADC_CLOCK_INTERNAL);
set_adc_channel(0);
delay_us(READ_SAMPLE_TIMES);
delay_ms(3000);
fprintf(DEBUG,"Arranco\r\n");
while(true){
lectura = read_adc(ADC_START_AND_READ);
fprintf(DEBUG,"ADC: %lu",lectura);
delay_ms(1000);
}
}
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And the second one:
Main.c
| Code: | void main(){
unsigned int16 lectura = 0;
ADON = 0; // ADC off
AD12B = 0; // 10 Bits
FORM_1 = 0; // unsigned int
FORM_0 = 0;
VCFG_2 = 0; // AVdd - AVss
VCFG_1 = 0;
VCFG_0 = 0;
CHPS_1 = 0; // converts ch0
CHPS_0 = 0;
ADRC =1; // Internal clock RC ADC
SAMC_4 = 0; // 0Tad
SAMC_3 = 0;
SAMC_2 = 0;
SAMC_1 = 0;
SAMC_0 = 0;
CH0SA_4 = 0; // AN0
CH0SA_3 = 0;
CH0SA_2 = 0;
CH0SA_1 = 0;
CH0SA_0 = 0;
ADON = 1; // ADC ON
delay_ms(3000);
fprintf(DEBUG,"Arranco\r\n");
while(true){
lectura = read_adc(ADC_START_AND_READ);
fprintf(DEBUG,"ADC: %lu",lectura);
delay_ms(1000);
}
}
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Main.h
| Code: | // ADC CONFIG
#WORD AD1CON1 = 0x0320 // ADON(15) - AD12B(10) - FORM(9,8)
#BIT ADON = AD1CON1.15
#BIT AD12B = AD1CON1.10
#BIT FORM_1 = AD1CON1.9
#BIT FORM_0 = AD1CON1.8
#WORD AD1CON2 = 0x0322 // VCFG(15,14,13) - CHPS(9,8)
#BIT VCFG_2 = AD1CON2.15
#BIT VCFG_1 = AD1CON2.14
#BIT VCFG_0 = AD1CON2.13
#BIT CHPS_1 = AD1CON2.9
#BIT CHPS_0 = AD1CON2.8
#WORD AD1CON3 = 0x0324 // ADRC(15) - SAMC(12,11,10,9,8)
#BIT ADRC = AD1CON3.15
#BIT SAMC_4 = AD1CON3.12
#BIT SAMC_3 = AD1CON3.11
#BIT SAMC_2 = AD1CON3.10
#BIT SAMC_1 = AD1CON3.9
#BIT SAMC_0 = AD1CON3.8
#WORD AD1CHS0 = 0x0328 // CH0SA(4,3,2,1,0)
#BIT CH0SA_4 = AD1CHS0.4
#BIT CH0SA_3 = AD1CHS0.3
#BIT CH0SA_2 = AD1CHS0.2
#BIT CH0SA_1 = AD1CHS0.1
#BIT CH0SA_0 = AD1CHS0.0
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In both cases I always see 512 value.
I have simplified the code, so there is some configurations that I have omitted
Do you have any idea how to solve this problem?
Any suggestion will be appreciated, thank you so much. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19551
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| Posted: Mon Nov 05, 2012 7:23 am |
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Obvious first thing, you have got Avdd, and AVss connected?. The supply for the ADC, is separate on these chips.
Best Wishes |
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mizzard
Joined: 26 Apr 2009
Posts: 11
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| Posted: Mon Nov 05, 2012 8:15 am |
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Yes, tested with multimeter. I have 3.3V on AVdd pin (number 19) and GND on pin number 20.
Another thing I have detected is when I use set_adc_channel(0) occurs that I have said, but when I use set_adc_channel(1), the dsPIC is continiously on reset.
I have checked an0, an1, Avss, and AVdd lines and I don't find any problem.  |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19551
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| Posted: Mon Nov 05, 2012 9:39 am |
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Wondering if fuse setup is not right, and it thinks these pins are to be used for ICD/programming. However if you can program the chip this doesn't make sense.
Best Wishes |
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mizzard
Joined: 26 Apr 2009
Posts: 11
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| Posted: Mon Nov 05, 2012 9:44 am |
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Here are my fuses:
| Code: |
#include <33EP256MU806.h>
#device adc=10
#FUSES NODEBUG //No Debug mode for ICD
#FUSES PUT128 //Power On Reset Timer value 128ms
#FUSES NOWDT //No Watch Dog Timer
#FUSES PR_PLL
#FUSES HS
#FUSES ICSP1
#FUSES OSCIO
#FUSES CKSFSM
#FUSES NOIOL1WAY //Allows multiple reconfigurations of peripheral pins |
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