Great thread this. ;)
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Great thread this. ;)
O.K. i'll stop here... at least by respect to our members and readers, and because it's not a chit-chat area.
...deleted...for obvious reasons :D
I just tried with a 20 turn 10k linear pot and its the same, once I reach the lower duty cycles the led flickers.Quote:
Originally Posted by mister_e
The difference is clearly visible with the multiturn pot, once you go below a certain level it flickers, move the other way a little bit and the flicker goes away
Reading in the flicker position I get this range: from $00BB to $00BF and spurious $009F , $00B4, $00C6, $00E3 at random places
Reading in the steady position I get this range: $00CD to $00CF and no spurious readings
I only read 125 word values into the device own eeprom.
Again Im using a li-ion battery for powering the circuit (3.65v)
Weird isnt it? even weirder is that sometimes when I write the values to eeprom the written values are steady (also visually) but only when writting...
Just in case here is the code I used:
Code:' Pic Configuration
@ device pic12f683,INTRC_OSC_NOCLKOUT , wdt_on, mclr_off, protect_off
' Hardware configuration
' I/Os
TRISIO = %00010010 ' pin1 is ADC , pin4 is the calibration button
' ADC's
ANSEL = %00000010
DEFINE ADC_BITS 10 ' ADCIN resolution (Bits)
DEFINE ADC_CLOCK 1 ' ADC clock source (Fosc/8)
DEFINE ADC_SAMPLEUS 11 ' ADC sampling time (uSec)
ADCON0.7 = 1 ' Right justified results
' Comparator
CMCON0 = %00000111 ' Disable comparator
VRCON = %00000000 ' disable
'cmcon0 = %00001110 ' Multiplexed Input with Internal Reference CIS=1
'vrcon = %10001010 ' set vref=2.25v (from 4v input)
include "HPWM10.pbp"
' definitions
pote var word
Frequency var word
calibraled var gpio.5
calibrapin var gpio.4
conta var byte
gpio=0
conta=0
frequency=1000
pause 50 ' coffee break
loop:
adcin 1, pote
if pote>1000 then pote=1000
if calibrapin=1 then
if conta < 250 then
write conta, pote.byte1
write conta+1, pote.byte0
conta=conta+2
endif
endif
@ HPWM10 1, _pote, _Frequency
pause 10
goto loop
end
Pablo
O.K. i have to go out. I had the same code, and i didn't have any problem...
when i'll be back, i'll use a lower voltage AND use HighBrightness LEDs.
Wish i could see the same thing....
Still thinking there's an hardware problem...
Pablo,
Good new, Bad news.
I finally found my 12F683 and gave it a go.
I've completely duplicated your problem. Blinking and all.
For some reason it only does it on the 683.
Every other chip I tried seems to work fine.
And the bad news is, I haven't found out why yet. (Operative word, Yet)
It appears to be with the A/D, the readings are all over the place at low voltage input.
I still have many things to try, but just wanted you to know you're not crazy.
And, I WILL find it. (unless somebody beats me to it)
<br>
As I see it its only good news :) Thanks for all your efforts!!!Quote:
Originally Posted by Darrel Taylor
I can't help with your code, is way beyond my actual knowledge, I hope to catch up with it in the future!
Now I patiently wait ;)
Pablo
An EE friend of mine (Thanks Doug) told me a new possibility about the cause of the problem:
What if reading the ADC so often does not give it enough time to handle the low voltage values?
(more discussions via chat with my friend)
He points out something interesting, the test program initializes the ADC using:
DEFINE ADC_BITS 10 ' ADCIN resolution (Bits)
DEFINE ADC_CLOCK 1 ' ADC clock source (Fosc/8)
DEFINE ADC_SAMPLEUS 11 ' ADC sampling time (uSec)
But reading the pic basic manual we have:
and the PAUSEUS section says:Quote:
ADC_SAMPLEUS is the number of microseconds the program waits
between setting the Channel and starting the analog to digital
conversion. This is the sampling time. The minimum number of
microseconds usable is determined by the minimum time for PAUSEUS.
See it’s section for this information.
So, the initial theory appears to be right, I don't have the protoboard here now, but I will check this tomorrow.Quote:
For 4mhz Minimum Delay is 24us
Pablo
I tried every AD oscillator / Sample time possible, and it made no difference.
Even with the A/D input tied directly to ground, it was getting crazy readings between 0 and 20.
After I tried it with a 12F675 (without the CCP) and got the same results,
I finally figured out that I had removed the big cap on the power lines on this protoboard.
Probably needed it for something else. Doh!
After putting a 100uf cap across the power supply, everything calmed down again.
It's still not perfect, but I think that has alot to do with the breadboard.
So then to really stabilize things I added an averaging routine, and I think that's about as close as we're going to get.
First make sure you have enough capacitance on your power lines (I think mister_e already suggested that).
Then add this to the bottom of the programAnd also, just after the ADCIN statement, add thisCode:' -=-=-=-=-=-= Average Analog values -=-=-=-=-=-=-=-=-=-=
Avg VAR WORD
AvgCount CON 16
spread CON 20
Average: ' Smooth data
IF ABS (pote - Avg) > spread then
Avg = pote
else
Avg = (Avg*(AvgCount-1)+pote)/AvgCount
pote = Avg
endif
Return
HTH,Code:gosub Average
it's getting interesting... i have everything on hand, will do some test here.
Sorry, i was suppose to do it yesterday :D :(
well I hope you find something because I tried adding a 100uF capacitor in the power lines or in parallel with the wiper and my problems remain, even after adding the averaging routine provided by Darrel.
I even started looking for other pic alternatives :( in case this can't be solved...
Thanks again
still working @ 3.x Volt?
yes Sir, using a 3.6v li-ion batt
Pablo
O.K. can you try to program you pic with the .HEX in attachment and let me know what's happening now?
Finger crossed...
it uses the circuit I provided right? will test it tomorrow and let you know. Thanks!!!Quote:
Originally Posted by mister_e
Yup it's the same circuit. CalibraPin is also implemented.
Here, it's working, no flicker or else... 'till now
yes it flickers, but this one instead of graduating continuously goes in steps, and the calibrapin button does nothing, at least nothing I can see or read.
Thanks!
can you try something because it's working really fine here... use another ADC channel, like GP4, or GP5.
what do you mean by using another ADC? change the my test program to read in another port ?Quote:
Originally Posted by mister_e
thanks
In your example you used ADCIN 1,pote to read GP1. Change it to ADCIN 5,pote. Sure you'll need to change your hardware and some regisers settings as well.
Next step will be to use a TIMER interrupt instead.
I will do two things, 1st etch a pcb for the circuit and test it again, second try with a 16F628AQuote:
Originally Posted by mister_e
I let you know. thanks!
made the etched pcb and only tried it with Mister_e hex file and it worked without flickerings. Im not sure if its supposed to smooth or in steps, I see steps.
More tests on monday. Thanks!!
steps are normal with my HEX. but good news! and thanks to report your results. Sure many code before my last one will now work as designed.
Hi, Darrel,
I just try tu make HPWM10 work aboard a 12F683 ...
and get the following Message ( MPASM compiler ) :
Error[108] C:\PROGRAM FILES\MICROCHIP\MPLAB IDE\PROJETS\SPEEDCOMM.ASM 185 : Illegal character (1)
the illegal character is ... the PWM Channel !!!
@ HPWM10 1, _DutyCycle, _Frequency
I used the example " straight out of the box ...
do you have any idea ???
Alain
re,
The idea is : change "HPWM10.pbp" into "HPWM.bas", for the include command.
Alain
There had to be more errors than that.Quote:
Originally Posted by Acetronics
The others might have had more clues, but it appears that PBP couldn't find the file.
Are you saying that you renamed it to HPWM.bas but still had INCLUDE "HPWM10.pbp"?
confused. :confused:
<br>
Hi, Darrel,Quote:
Originally Posted by Darrel Taylor
Hoooo ... bad evening ! was HPWM10.pbp into HPWM10.bas.
the goal was to transform a R/C pulse into a corresponding 10 bits PWM @ 10 kHz ... and drive a "Diesel engine" sound machine.
Have a nice week end.
Alain
Hi, Darrel
I Was a bit surprised by those lines :
are those 6 times " GOTO _GetCH_2 " ( L368 , 370 - 373 , 378 ) something " regular " ???Code:
Line Address Opcode Label Disassembly
359 166 00BD MOVWF 0x3d
360 167 084C MOVF _HP_Channel, W
361 168 3C05 SUBLW 0x5
362 169 1C03 BTFSS STATUS, 0
363 16A 2975 GOTO L00001
364 16B 3001 MOVLW 0x1
365 16C 008A MOVWF PCLATH
366 16D 084C MOVF _HP_Channel, W
367 16E 0782 ADDWF PCL, F
368 16F 297A GOTO _GetCH_2
369 170 2975 GOTO L00001
370 171 297A GOTO _GetCH_2
371 172 297A GOTO _GetCH_2
372 173 297A GOTO _GetCH_2
373 174 297A GOTO _GetCH_2
374 175 0813 L00001 MOVF CCPR1L, W
375 176 00C0 MOVWF _HP_Temp
376 177 0815 MOVF CCP1CON, W
377 178 00C1 MOVWF _HP_Temp??HIGHBYTE
378 179 297A GOTO _GetCH_2
379 17A 0840 _GetCH_2 MOVF _HP_Temp, W
380 17B 00A0 MOVWF BANK0_START
381 17C 01A1 CLRF 0x21
382 17D 3002 MOVLW 0x2
383 17E 205A CALL SHIFTL
the source for 12F683 @ 8 Mhz internal is :
RegardsCode:@ __config _INTRC_OSC_NOCLKOUT &_FCMEN_OFF &_IESO_OFF & _WDT_ON &_PWRTE_ON & _MCLRE_OFF & _CP_OFF
OSCCON = %01110111 ' Internal Clock 8 Mhz
CMCON0 = 7
VRCON = 0
ADCON0 = 0
ANSEL = 0
DEFINE OSC 8 'Declare 8 Mhz operation
DEFINE PULSIN_MAX 4500
' PINS DEFINITIONS
Signal var GPIO.3
Drive var GPIO.2
GPIO = 0
TRISIO = %00001000
' VARIABLE DEFINITIONS
speed var Word ' assign Word variable to speed demand
w1 var Word ' Table output
DutyCycle VAR WORD
Frequency VAR WORD
Temp VAR WORD
include "HPWM10.bas"
LOW Drive ; Set CCP1 pin to output low
Frequency = 10000
'******************************************************************************
'MAIN LOOP
main:
pulsin Signal,0,speed ' Read servo pulse ( Inverted !!! )
'******************************************************************************
' Throttle amount topped to 100 and reduced to 25 steps
if speed > 300 then
speed = ( speed - 300 )MIN 100
else
speed = ( 300 - speed )MIN 100
endif
speed = speed >> 2
'******************************************************************************
' Conversion logarithmique 10 bits - 800 maxi à 10 khz
lookup2 speed, [0,0,161,277,378,467,543,611,670,721,766,804,836,867,893,_
933,950,965,978,990,1000,1009,1017,1023,1023 ],w1
'******************************************************************************
' !!! Passer en " HPWM 10 " !!!
if w1 <> DutyCycle then DutyCycle = w1
@ HPWM10 1, _DutyCycle, _Frequency
goto main
END
Alain
The lines showing the same labels is the result of Disassembling.Quote:
Originally Posted by Acetronics
There are actually 6 different labels, with the code in-between optimized out since the chip doesn't have 5 CCP modules.
It comes from this section ...
The GOTO's are created by the Branch statement.Code:;----- Get Current DutyCycle ------------------------------------------------
Branch HP_Channel,[GetCH_Done,GetCH_1,GetCH_2,GetCH_3,GetCH_4,GetCH_5]
GetCH_1:
ASM
ifdef CCP1CON
MOVE?BB CCPR1L, _HP_Temp
MOVE?BB CCP1CON, _HP_Temp + 1
goto _GetCH_Done
endif
endasm
GetCH_2:
ASM
ifdef CCP2CON
MOVE?BB CCPR2L, _HP_Temp
MOVE?BB CCP2CON, _HP_Temp + 1
goto _GetCH_Done
endif
endasm
And it looks like this in the .LST file ...Since the labels are all at the same address, the disassembler chooses the first label it finds at that address (_GetCH_2).Code:016B 3001 M movlw (jmptbl) >> 8
016C 008A M movwf PCLATH
016D 084C M movf _HP_Channel, W
016E 0782 M addwf PCL, F
016F M jmptbl
016F 297A M goto _GetCH_Done
0170 2975 M goto _GetCH_1
0171 297A M goto _GetCH_2
0172 297A M goto _GetCH_3
0173 297A M goto _GetCH_4
0174 297A M goto _GetCH_5
0175 M L00001
0175 M _GetCH_1
0175 0813 M movf CCPR1L, W
0176 00C0 M movwf _HP_Temp
0177 0815 M movf CCP1CON, W
0178 00C1 M movwf _HP_Temp + 1
0179 297A 00326 goto _GetCH_Done
017A M _GetCH_2
017A M _GetCH_3
017A M _GetCH_4
017A M _GetCH_5
017A M _GetCH_Done
Hi, Darrel
Tanks for your explanation
Alain
Hello,
I would have two different frequency on CCP1 and CCP2 pin the first is 100HZ and second is 20Khz-40KHz. I use 1MHz quartz for clock and HPWM10 command from D.T. I use PIC16F876.
I have on both CCP pin HPWM10 command with frequency 100hz and different duty. This working ok. When changed frequency on CCP1 to 1KHz then is frequency on both pin unchanged and very unstable
When change one HPWM10 command to normal 8 bit HPWM then stay result unchanged.
what I did wrong?
here is first part of my program:
INCLUDE "ALLDIGITAL.pbp"
Cifra var byte
Cifra1 var byte
Maska1 var byte
Maska2 var byte
W var byte
i var byte
time var byte
PR var byte
VU var word
VD var word
Duty VAR word
Duty1 VAR word
FREQUENCY var word
FREQUENCY1 var word
LED var PORTC.4
LEDDis1 var PORTA.0
LEDDis2 var PORTA.1
tipka1 var porta.2
tipka2 var porta.3
tipka3 var porta.4
BUZ var porta.5
enable1 var portc.0
b0 var byte
b1 var byte
b2 var byte
b3 var byte
impulz var WORD
minuta var byte
key var byte
pavza var word
bp var byte
TRISA=%11111100
TRISB=%00000000
TRISC=%00000000
clear
include "HPWM10.pbp"
LOW PORTC.1
LOW PORTC.2
PWM_ON CON %00001100
PWM_OFF CON 0
time=6
FREQUENCY=93 '
FREQUENCY1=1000
low led
gosub zvok
eeprom 0,[31]
eeprom 2,[55]
high enable1
high led
pause 100
low led
INTCON = %00100000
OPTION_REG = %10001000
On Interrupt Goto ISR
INTCON = %10100000
w=0
Main:
gosub tipka
gosub timing
read 0,b2
gosub tpwm
@ HPWM10 2,_IMPULZ,_FREQUENCY
read 2,b0
gosub ppwm
@ HPWM10 1,_duty,_FREQUENCY1
Gosub Priprava
goto Main
ppwm: b1=b0-50
lookup2 b1,[100,200,300,400,500,600,700,800,900,1000],duty
return
tpwm: b3=b2-30
lookup b3,[0,31,16,6,21,46],duty1
return
With 16F876's, both CCP modules use the same Timer in PWM mode (TMR2).
If you change the frequency of one, the other one changes too.
With a 4 Mhz crystal, the minimum HPWM frequency is 245 Hz.
Since you are using a 1 Mhz crystal, you can get down to 62 Hz, but you have to specify the frequency as if it were running at 4 Mhz.
If you want 100 Hz, then specify 400 Hz in the HPWM10 command.
93 is way below the minimum.
<br>
Frequency of 100 Hz is not a problem. In the case that I use PIC16F886 asking whether the command HPWM10 set timer TMR1 and TMR2 for each channel?
Can you write the registry settings for the PIC16F886?
tnx
Samo
Even on a PIC16F887, the CCP modules can only use Timer2 in PWM mode.
So both PWM channels will operate at the same frequency.
So I guess the answer to your question is ...
HPWM10 only changes Timer2, not Timer1.
<br>
Darrel,
Whats required to have 'glitch free' operation but with 8 bit PWM, can the include file be easily modified for 8 bit, or should i just multiply my desired 8 bit dutycycle by 4?
Also, just testing on 16F887, at 4mhz,
@ HPWM10 1,_OUTDUTY,300 results in a PWM frequency of 10khz according to my o'scope ???
I see the duty cycle changing, but the freq is around 9-10khz?
The frequency must be a variable.
You can't pass a constant as the parameter.
And just shift left 2 (<<2) to use 8-bit values.
hth,
Old thread but very relevant to my issue.
Can I use HPWM10:
1. On an 18F87J50?
2. And have it glitch free?
3. To make a pulse train that's 140mS long and have varying duty cycles within the pulse train?
In other words: 300uS on, 200uS off, 300uS on on, 200uS off, 130uS on, 370 uS off, 300uS on, 200uS off, 130uS on, 370uS off, 170uS on, 330uS off, 130uS on, 370uS off, etc.
Each bit is 500uS and I don't need to modify anything while the packet is being sent; I can modify right before the next one is sent.
If by “glitch free” you mean free of any resolution error, not every frequency or duty cycle you want to generate will be.
for any particular frequency, you need the pic’s clock frequency to tell you that.
This online PWM calculator can tell you:
http://www.micro-examples.com/public...alculator.html
whether or not you can change it for arbitrary duration for every pulse like that would be a tough one,
I don’t think that’s possible, but might be wrong.
Depending what else the chip has to do, it might be possible to use timer1 overflow that way.