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Re: SOLVED: How can I reduce ADC drift
On a PCB of a irrelevant project I tested the simple ADCin and display the result on the LCD.
As Richard says the +/-1 LSB is what I get with no process. Occasionaly 2 LSBs.
I just sample every sec. and display it.
Of course the PCB is double sided with lot of ground, a cap on the ADC input pin and linear 5Volt regulator. So any external noise is minimized.
Breadboards are just a noise antennas and never give clean results.
Ioannis
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Re: SOLVED: How can I reduce ADC drift
Ultimately, the system has to be able to read ADC while managing to 2-3 LED strips and 4 LCDs with PWM.
I'm trying a double PSU approach to see if the input PIC (right) can keep line noise to a minimum, and have all output functions on the output PIC (left).
Input functions will consume very little current, it's the output functions that will consume a lot more, and have multiple PWMs.
The only unknown is the rotary encoders; no idea if their rapid ON-OFF will create noise. I can always move them over to the output PIC.
At worse, I'd end up with a "clean" PIC, and a "noisy" PIC instead of input/output.
My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.
Not as dumb as yesterday, but stupider than tomorrow!
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Re: SOLVED: How can I reduce ADC drift
I've gone back to getting a "basic" ADC routine working for 1 voltage-divider and 2 pots (for a better sampling).
Code:#CONFIG __config _CONFIG1, _FEXTOSC_OFF & _RSTOSC_HFINT32 & _CLKOUTEN_OFF & _CSWEN_OFF & _FCMEN_ON __config _CONFIG2, _MCLRE_ON & _PWRTE_OFF & _LPBOREN_OFF & _BOREN_ON & _BORV_LO & _ZCD_OFF & _PPS1WAY_OFF & _STVREN_ON & _DEBUG_OFF __config _CONFIG3, _WDTCPS_WDTCPS_11 & _WDTE_OFF & _WDTCWS_WDTCWS_7 & _WDTCCS_LFINTOSC __config _CONFIG4, _WRT_OFF & _SCANE_available & _LVP_OFF __config _CONFIG5, _CP_OFF & _CPD_OFF #ENDCONFIG DEFINE OSC 32 DEFINE ADC_BITS 10 ' 10-bit Analog to digital DEFINE ADC_SAMPLEUS 50 ' Set sampling time in uS DEFINE HSER_RXREG PORTC DEFINE HSER_RXBIT 7 DEFINE HSER_TXREG PORTC DEFINE HSER_TXBIT 6 DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive DEFINE HSER_TXSTA 24h ' Enable transmit, BRGH = 1 Define HSER_BAUD 115200 DEFINE HSER_CLROERR 1 ' Clear overflow automatically DEFINE HSER_SPBRGH 0 DEFINE HSER_SPBRG 68 ;--- Setup registers ----------------------------------------------------------- BAUDCON.3 = 1 ' Enable 16 bit baudrate generator FVRCON = %10000011 ' FIXED VOLTAGE REFERENCE CONTROL REGISTER ' bit 7 FVREN: Fixed Voltage Reference Enable bit ' ---> 1 = Fixed Voltage Reference is enabled ' bit 1-0 ADFVR<1:0>: ADC FVR Buffer Gain Selection bit ' ---> 11 = ADC FVR Buffer Gain is 4x, (4.096V)(2) ADCON0 = %10000100 ' ADC CONTROL REGISTER 0 ' bit 7 ADON: ADC Enable bit ' ---> 1 = ADC is enabled ' bit 2 ADFRM0: ADC results Format/alignment Selection ' ---> 1 = ADRES and ADPREV data are right-justified ADCON2 = %00000000 ' ADC CONTROL REGISTER 2 ' bit 2-0 ADMD<2:0>: ADC Operating Mode Selection bits(1) ' ---> 000 = Basic (Legacy) mode ADCLK = %00111111 ' ADC CLOCK SELECTION REGISTER ' bit 5-0 ADCCS<5:0>: ADC Conversion Clock Select bits ' ---> 111111 = FOSC/128 ADREF = %00000011 ' ADC REFERENCE SELECTION REGISTER ' bit 4 ADNREF: ADC Negative Voltage Reference Selection bit ' ---> 0 = VREF- is connected to AVSS ' bit 1-0 ADPREF: ADC Positive Voltage Reference Selection bits ' ---> 11 = VREF+ is connected to FVR_buffer 1 ADPCH = %00000000 ' ADC POSITIVE CHANNEL SELECTION REGISTER ' ---> 000000 = ANA0 ANSELA = %00000111 ' Pin A2 = ADC (B5K) ' Pin A1 = ADC (B5K) ' Pin A0 = ADC (voltage divider) ANSELB = %00000000 ANSELC = %00000000 TRISA = %00000111 ' Pin A2 = ADC input 2 ' Pin A1 = ADC input 1 ' Pin A0 = ADC input 0 TRISB = %00000000 ' Pin B7 = ...not available, ICSPDAT ' Pin B6 = ...not available, ICSPCLK TRISC = %11000000 ' Pin C7 = RX *** Datasheet requirement, INPUT *** ' Pin C6 = TX *** Datasheet requirement, INPUT *** ADCinput var WORD ADCtot var WORD ADCcalc var WORD ADCdiff var WORD ADCLoop VAR BYTE OldADC0 var WORD OldADC1 var WORD OldADC2 var WORD Pause 500 ' Let PIC and LCD stabilize ADCinput = 0 : ADCdiff = 0 OldADC0 = 9999 : OldADC1 = 9999 : OldADC2 = 9999 Mainloop: rem ADC0, 4K7-4K7 voltage divider adcin 0, ADCinput : Pauseus 1 ' preliminary ADCIN to establish channel used ADCtot = 0 FOR ADCLoop = 0 TO 15 ' Load 16 ADC values adcin 0, ADCinput : Pauseus 1 ADCtot = ADCtot + ADCinput NEXT ADCLoop ADCcalc = ADCtot / 16 ' Average out if ADCcalc < oldADC0 then ' Calculate change in ADC ADCdiff = oldadc0 - ADCcalc else ADCdiff = ADCcalc - oldadc0 endif IF (ADCdiff > 2) or _ ' Check for Diff over 2 ... OR ((adccalc <> oldadc0) and _ ' ADC value changed ... AND (adccalc = 0 or adccalc = 1023)) then ' Reached end of rotation hserout [ "OldADC0:", DEC4 oldadc0, " ", _ " ", _ "ADCin:", DEC4 ADCcalc, " ", _ "Diff:", dec4 ADCdiff, " ", _ "Sum:", Dec5 ADCtot, 10] while TXSTA.1 = 0 ' Check TRMT bit wend oldADC0 = ADCcalc endif rem ADC1, B5K pot adcin 0, ADCinput : Pauseus 1 ' preliminary ADCIN to establish channel used ADCtot = 0 FOR ADCLoop = 0 TO 15 ' Load 16 ADC values adcin 1, ADCinput : Pauseus 1 ADCtot = ADCtot + ADCinput NEXT ADCLoop ADCcalc = ADCtot / 16 ' Average out if ADCcalc < oldADC1 then ' Calculate change in ADC ADCdiff = oldadc1 - ADCcalc else ADCdiff = ADCcalc - oldadc1 endif IF (ADCdiff > 2) or _ ' Check for Diff over 2 ... OR ((adccalc <> oldadc1) and _ ' ADC value changed ... AND (adccalc = 0 or adccalc = 1023)) then ' Reached end of rotation hserout [ " ", _ "OldADC1:", DEC4 oldadc1, " ", _ " ", _ "ADCin:", DEC4 ADCcalc, " ", _ "Diff:", dec4 ADCdiff, " ", _ "Sum:", Dec5 ADCtot, 10] while TXSTA.1 = 0 ' Check TRMT bit wend oldADC1 = ADCcalc endif rem ADC2, B5K pot adcin 2, ADCinput : Pauseus 1 ' preliminary ADCIN to establish channel used ADCtot = 0 FOR ADCLoop = 0 TO 15 ' Load 16 ADC values adcin 2, ADCinput : Pauseus 1 ADCtot = ADCtot + ADCinput NEXT ADCLoop ADCcalc = ADCtot / 16 ' Average out if ADCcalc < oldADC2 then ' Calculate change in ADC ADCdiff = oldadc2 - ADCcalc else ADCdiff = ADCcalc - oldadc2 endif IF (ADCdiff > 2) or _ ' Check for Diff over 2 ... OR ((adccalc <> oldadc2) and _ ' ADC value changed ... AND (adccalc = 0 or adccalc = 1023)) then ' Reached end of rotation hserout [ " ", _ "OldADC2:", DEC4 oldadc2, " ", _ "ADCin:", DEC4 ADCcalc, " ", _ "Diff:", dec4 ADCdiff, " ", _ "Sum:", Dec5 ADCtot, 10] while TXSTA.1 = 0 ' Check TRMT bit wend oldADC2 = ADCcalc endif GOTO Mainloop end
Checklist:
- PIC 16F18855,
- used legacy ADC (no ADC2),
- did not touch VREFs,
- used FVR 4x with 5 VDC in,
- used FOSC / 128,
- used average of 16 ADC readings,
- removed all LCD logic (used for debugging),
- used USART to show results
- added PAUSEUS 1 after all ADC operations - THIS NEEDS TO BE VERIFIED IF IT'S NECESSARY, it was just to make sure things worked.
ADC readings on the voltage-divider and 2 rotary pots did not "drift/vary/whatever" more than 2.
I still have to:
- try with slide pots, just to see if that fixed their "irregularities" that I experienced in the past.
- reconnect the 2nd breadboard that displays to LCD with backlight PWM, and PWMs 2 LED strips.
EDIT: This was working perfectly with the voltage divider (ADC0) and pot 2 (ADC2), now that I've put back in pot 1 (ADC1), the 2 pots don't reach 0 and stop at 2.
ARGH...
Last edited by Demon; - 3rd March 2025 at 03:16.
My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.
Not as dumb as yesterday, but stupider than tomorrow!
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Re: SOLVED: How can I reduce ADC drift
- did not touch VREFs,
What do you mean by this , you have changes pos vref to fvr buffer1- used FVR 4x with 5 VDC in,
which will turn out to be a mistake since pots use vdd as top input , by doing this you have lost 20% of their travel range
Anything over VREF+ will be interpreted as the max ADC output. Anything lower than VREF- will be interpreted as the min ADC output value.
There will be no damage if you exceed VREF+/VREF- as long as you don't exceed Vdd/Vss
- used FOSC / 128,way too slow , while not out of acceptable range fosc/32 is more reasonable
- used average of 16 ADC readings,not sure about that , its not necessary either if every thing else is ok
- used USART to show results
- added PAUSEUS 1 after all ADC operations - THIS NEEDS TO BE VERIFIED IF IT'S NECESSARY, it was just to make sure things worked.
it does nothing useful
my schema , added another supply rail straddling 10k pot , without series wiper resistor to an2
not no none nil caps across an inputs
typical raw readings
Code:R 827 669 R 826 669 R 826 669 R 826 668 R 825 669 R 827 669 R 826 669 R 826 669 R 826 668 R 825 668 R 827 670 R 826 669 R 825 668 R 827 669 R 827 669
#CONFIG
__config _CONFIG1, _FEXTOSC_OFF & _RSTOSC_HFINT32 & _CLKOUTEN_OFF & _CSWEN_ON & _FCMEN_ON
__config _CONFIG2, _MCLRE_ON & _PWRTE_OFF & _LPBOREN_OFF & _BOREN_ON & _BORV_LO & _ZCD_OFF & _PPS1WAY_OFF & _STVREN_ON & _DEBUG_OFF
__config _CONFIG3, _WDTCPS_WDTCPS_11 & _WDTE_ON & _WDTCWS_WDTCWS_7 & _WDTCCS_LFINTOSC
__config _CONFIG4, _WRT_OFF & _SCANE_available & _LVP_ON
__config _CONFIG5, _CP_OFF & _CPD_OFF
#ENDCONFIG
DEFINE OSC 32
DEFINE DEBUG_REG PORTC
DEFINE DEBUG_BIT 0 ; if not used for pwr
DEFINE DEBUG_BAUD 9600
DEFINE DEBUG_MODE 0
DEFINE ADC_BITS 10 ' 10-bit Analog to digital
DEFINE ADC_SAMPLEUS 5 ' Set sampling time in uS
ANSELA = % 00000101 ' Pins A0 A2 = ADC
TRISA = % 11101111 ' Pin A4 = LED
TRISD = % 11111011 ' DEBUG
LATC.0 = 1 ' DEBUG
clear
LED VAR LATA.4
i var byte
j var word
bucket var WORD
ADCinput var WORD
mean var WORD
buckets var word[21]
outlier var WORD
LED = 1 'Proof of Life
PAUSE 2000
DEBUG 13,10,"READY",13,10
FVRCON = % 10000011
;ADCON0 = % 10000100 ;NOT USED
ADREF = % 00000000
ADCLK = 15
LED=0
Mainloop:
;NOTE an inputs sampled twice to overcome pbp poor adc ch changes
ADCIN 0, ADCinput
ADCIN 0, ADCinput
DEBUG 13,10,"R ",DEC ADCinput,9
ADCIN 2, ADCinput
ADCIN 2, ADCinput
DEBUG DEC ADCinput
PAUSE 500
GOTO Mainloop
end
i just tried it without the double adc reads on input change and it works ok , so that's not an issue anymore it seems
[i very rarely if ever use the adcin command , prefer to use asm sequences instead]
Last edited by richard; - 3rd March 2025 at 04:51.
Warning I'm not a teacher
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Re: SOLVED: How can I reduce ADC drift
Lets clarify something Robert please.
Do you expect to have an ADC reading that will be absolutely stable on every pot position? Say that a user can set 1023 positions on the pot. Do you expect to have solid 1023 readings?
This cannot be done no matter what. On an absolutely perfect circuit you will get +/- 1 digit because of the way ADC works along with every kind of noise present (wire induced, ground loops, resistors noise, shot noise, Johnson noise and so many other kinds).
The ADC steps are 5/1023= 4.8876mV. This means that if ADC input is over that step, you get a count of 1. But if one of the above noise or more than one is present, you may get 0 or even 2 as a result, if the noise adds another 4.88mv.
Hope this is clear and helps you not chasing the impossible.
Any kind of averaging helps but because of the above, it does not eliminate the small jitter that you should accept.
Averaging with Moving average routine limits the maximum number of counts. The one Richard posted on #57 goes up to 1004 after about 30 samples. Darrels Taylor Oversampling routine does also suffer of this kind of problem. Well gives from 8bit ADC a 16bit result but you have to pay in time...
Best keep a simple average of 10 samples and get done with it.
Ioannis
Last edited by Ioannis; - 4th March 2025 at 00:03. Reason: Corrected the #XX post to #57
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Re: SOLVED: How can I reduce ADC drift
No, I was expecting a reading ranging between 0 and 1023, with 256 near 1/4 rotation (from available travel or course), 512 midway and 768 about 3/4 through.Originally Posted by Ioannis
My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.
Not as dumb as yesterday, but stupider than tomorrow!
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Re: SOLVED: How can I reduce ADC drift
Yes, you can expect that, depending on the pot of course.
But the readings will have a play around the specific point, because of what I explained.
Ioannis
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Re: SOLVED: How can I reduce ADC drift
I meant, did not touch VREF-, sorry.
If I use VREF+ = VDD, my ADC readings stop at 1000 or so.
If I use VREF+ = FVRx4, my readings reach 1023.
Weird.
...- used FOSC / 128,way too slow , while not out of acceptable range fosc/32 is more reasonable...
I've switched to 32 as well.
...used average of 16 ADC readings,If I don't use averages, I jump all over like this:not sure about that , its not necessary either if every thing else is ok ...
Code:OldADC1:00847 ADCin:00844 Diff:00003 OldADC1:00844 ADCin:00847 Diff:00003 OldADC1:00847 ADCin:00844 Diff:00003 OldADC1:00844 ADCin:00848 Diff:00004 OldADC1:00848 ADCin:00845 Diff:00003 OldADC1:00845 ADCin:00848 Diff:00003 OldADC1:00848 ADCin:00844 Diff:00004
I removed them....- used USART to show results
- added PAUSEUS 1 after all ADC operations - THIS NEEDS TO BE VERIFIED IF IT'S NECESSARY, it was just to make sure things worked.
it does nothing useful ...
Envious emote......my schema , added another supply rail straddling 10k pot , without series wiper resistor to an2
not no none nil caps across an inputs
typical raw readings
Code:R 827 669 R 826 669 R 826 669 R 826 668 R 825 669 R 827 669 R 826 669 R 826 669 R 826 668 R 825 668 R 827 670 R 826 669 R 825 668 R 827 669 R 827 669
Reduced mine from 50 down to 5 as well...
DEFINE ADC_BITS 10 ' 10-bit Analog to digital
DEFINE ADC_SAMPLEUS 5 ' Set sampling time in uS...
I just noticed that my temps on the 16F18855 goes over 100c when ADC runs; that's insane. I have no other routines running. If I stop ADC, it comes back down to 30ies.
I took everything non-essential off the breadboard (just kept my 2 power LEDs):
I know I can join those Ifs to check for end of rotation, I just wanted to keep code simple to make sure everything was getting picked up.Code:#CONFIG __config _CONFIG1, _FEXTOSC_OFF & _RSTOSC_HFINT32 & _CLKOUTEN_OFF & _CSWEN_OFF & _FCMEN_ON __config _CONFIG2, _MCLRE_ON & _PWRTE_OFF & _LPBOREN_OFF & _BOREN_ON & _BORV_LO & _ZCD_OFF & _PPS1WAY_OFF & _STVREN_ON & _DEBUG_OFF __config _CONFIG3, _WDTCPS_WDTCPS_11 & _WDTE_OFF & _WDTCWS_WDTCWS_7 & _WDTCCS_LFINTOSC __config _CONFIG4, _WRT_OFF & _SCANE_available & _LVP_OFF __config _CONFIG5, _CP_OFF & _CPD_OFF #ENDCONFIG DEFINE OSC 32 DEFINE ADC_BITS 10 ' 10-bit Analog to digital DEFINE ADC_SAMPLEUS 5 ' Set sampling time in uS DEFINE HSER_RXREG PORTC DEFINE HSER_RXBIT 7 DEFINE HSER_TXREG PORTC DEFINE HSER_TXBIT 6 DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive DEFINE HSER_TXSTA 24h ' Enable transmit, BRGH = 1 Define HSER_BAUD 115200 DEFINE HSER_CLROERR 1 ' Clear overflow automatically DEFINE HSER_SPBRGH 0 DEFINE HSER_SPBRG 68 ;--- Setup registers ----------------------------------------------------------- BAUDCON.3 = 1 ' Enable 16 bit baudrate generator FVRCON = %10000011 ' FIXED VOLTAGE REFERENCE CONTROL REGISTER ' bit 7 FVREN: Fixed Voltage Reference Enable bit ' 1 = Fixed Voltage Reference is enabled ' bit 1-0 ADFVR<1:0>: ADC FVR Buffer Gain Selection bit ' 11 = ADC FVR Buffer Gain is 4x, (4.096V)(2) 'ADCON0 = %10000100 ' ADC CONTROL REGISTER 0 ' bit 7 ADON: ADC Enable bit ' 0 = ADC is disabled ' 1 = ADC is enabled ' bit 2 ADFRM0: ADC results Format/alignment Selection ' 1 = ADRES and ADPREV data are right-justified ' 0 = ADRES and ADPREV data are left-justified, zero-filled ADCLK = %00001111 ' ADC CLOCK SELECTION REGISTER ' bit 5-0 ADCCS<5:0>: ADC Conversion Clock Select bits ' 001111 = FOSC/32 ADREF = %00000011 ' ADC REFERENCE SELECTION REGISTER ' bit 4 ADNREF: ADC Negative Voltage Reference Selection bit ' 0 = VREF- is connected to AVSS ' bit 1-0 ADPREF: ADC Positive Voltage Reference Selection bits ' 11 = VREF+ is connected to FVR_buffer 1 ' 00 = VREF+ is connected to VDD ANSELA = %00000010 ' Pin A1 = ADC (B5K) ANSELB = %00000000 ANSELC = %00000000 TRISA = %00000010 ' Pin A1 = ADC input 1 TRISB = %00000000 ' Pin B7 = ...not available, ICSPDAT ' Pin B6 = ...not available, ICSPCLK TRISC = %11000000 ' Pin C7 = RX *** Datasheet requirement, INPUT *** ' Pin C6 = TX *** Datasheet requirement, INPUT *** ADCinput var WORD ADCdiff var WORD OldADC1 var WORD Pause 500 ' Let PIC and LCD stabilize ADCinput = 0 ADCdiff = 0 OldADC1 = 9999 Mainloop: rem ADC1, B5K pot adcin 1, ADCinput ADCinput = ADCinput >> 6 ' tried left justified for fun if ADCinput < oldADC1 then ' Calculate change in ADC ADCdiff = oldadc1 - ADCinput else ADCdiff = ADCinput - oldadc1 endif IF ADCdiff > 2 then ' Check for Diff over 2 hserout [ "OldADC1:", DEC5 oldadc1, " ", _ "ADCin:", DEC5 ADCinput, " ", _ "Diff:", DEC5 ADCdiff, 10] while TXSTA.1 = 0 ' Check TRMT bit wend oldADC1 = ADCinput else if ADCinput <> oldadc1 then ' ADC value diff than previous if ADCinput = 0 then ' Reached end of rotation hserout [ "OldADC1:", DEC5 oldadc1, " ", _ "ADCin:", DEC5 ADCinput, " ", _ "Diff:", DEC5 ADCdiff, " ", 10] while TXSTA.1 = 0 ' Check TRMT bit wend oldADC1 = ADCinput else if ADCinput = 1023 then ' Reached start of rotation hserout [ "OldADC1:", DEC5 oldadc1, " ", _ "ADCin:", DEC5 ADCinput, " ", _ "Diff:", DEC5 ADCdiff, 10] while TXSTA.1 = 0 ' Check TRMT bit wend oldADC1 = ADCinput endif endif endif endif GOTO Mainloop end
Averages was why sometimes it would not reach 0 or 1023.
It works, but it has jumps of 3 now. Gonna see if more caps can reduce that.
No clue why ADC is running so hot, specs say 85c is normal operating temp.
The mounting holes are "slightly" warm, never noticed that before.
My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.
Not as dumb as yesterday, but stupider than tomorrow!
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Re: SOLVED: How can I reduce ADC drift
I just checked the mounting holes on my test LCD, the holes do the same thing and the LCD hasn't been connected in days.
Copper/bare metal is at a different temp than the rest so the scanner detects it.
My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.
Not as dumb as yesterday, but stupider than tomorrow!
|
Re: SOLVED: How can I reduce ADC drift
Either my PIC is damaged, or something is whacked inside the breadboard.
105c and wasn't stopping.
Code:#CONFIG __config _CONFIG1, _FEXTOSC_OFF & _RSTOSC_HFINT32 & _CLKOUTEN_OFF & _CSWEN_OFF & _FCMEN_ON __config _CONFIG2, _MCLRE_ON & _PWRTE_OFF & _LPBOREN_OFF & _BOREN_ON & _BORV_LO & _ZCD_OFF & _PPS1WAY_OFF & _STVREN_ON & _DEBUG_OFF __config _CONFIG3, _WDTCPS_WDTCPS_11 & _WDTE_OFF & _WDTCWS_WDTCWS_7 & _WDTCCS_LFINTOSC __config _CONFIG4, _WRT_OFF & _SCANE_available & _LVP_OFF __config _CONFIG5, _CP_OFF & _CPD_OFF #ENDCONFIG DEFINE OSC 4 ANSELA = %00000010 ' Pin A1 = ADC (B5K) ANSELB = %00000000 ANSELC = %00000000 TRISA = %00000010 ' Pin A1 = ADC input 1 TRISB = %00000000 ' Pin B7 = ...not available, ICSPDAT ' Pin B6 = ...not available, ICSPCLK TRISC = %11000000 ' Pin C7 = RX *** Datasheet requirement, INPUT *** ' Pin C6 = TX *** Datasheet requirement, INPUT *** ADCinput var WORD Pause 500 ' Let PIC and LCD stabilize ADCinput = 0 Mainloop: adcinput = 1023 end
My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.
Not as dumb as yesterday, but stupider than tomorrow!
|
Re: SOLVED: How can I reduce ADC drift
i simply hate this , all these pins made into outputs , shorted to gnd , no attempt to set them low
at power up are they low? before you short it all out
worst idea ever for breadboarding , i leave all pins as inputs unless they need to be an output
all this care re floating inputs is complete bull shit. for a battery operated device it will save a few microwatts that's it.
for the finished manufactured product sure do it , for bread boarding its dangerous nonsense where every mistake will be a bad one
Code:TRISA = %00000010 ' Pin A1 = ADC input 1 TRISB = %00000000 ' Pin B7 = ...not available, ICSPDAT ' Pin B6 = ...not available, ICSPCLK TRISC = %11000000
and all the dangerous groundsI took everything non-essential off the breadboard (just kept my 2 power LEDs):
Warning I'm not a teacher
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Re: SOLVED: How can I reduce ADC drift
I realized something was seriously wrong when that nothing circuit was taking 670mA. I added:
Before the ANSELx and TRISx and it's taking 20mA now, 33c with no ADC, just ADCinput set at 1023 and the HSEROUT loop.Code:PORTA = %00000000 PORTB = %00000000 PORTC = %00000000
My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.
Not as dumb as yesterday, but stupider than tomorrow!
|
Re: SOLVED: How can I reduce ADC drift
I try to keep my development code as close to final as possible, cause I know I'll forget to change stuff back. At least this way I can fire and forget the pin initialization.
But yeah, major bonehead move on my part. I put the old PIC back in and it runs at 20mA too. Gonna leave that 1st PIC in, just in case I do some other numbnut thing.
Thanks mucho Richard.
EDIT: Now this warning will follow my code for the rest of the development.
Code:PORTA = %00000000 '-------------------------------------------' PORTB = %00000000 ' ALWAYS SET PINS LOW FIRST ' PORTC = %00000000 '-------------------------------------------'
Last edited by Demon; - 4th March 2025 at 04:26.
My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.
Not as dumb as yesterday, but stupider than tomorrow!
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