Semi-random INT count???

Last night, the azimuth on my dish was counting up 11541 to move the dish 180 deg. I changed NOTHING. I went to bed and came in this morning, and now it's only 3100. Now, in my code, I have it intentionally stepped down to only count every 10th pulse from the encoder, but I did not change it. I did this because on arduino, it was showing ~100,000 pulses @ 180 deg and the PIC I'm using doesn't support LONG.

It was doing this to me on the elevation randomly. Maybe it still is, it just isn't showing itself. The elevation should only be 3600+ counts full travel. That's what it was with an arduino 3 months ago when I started this project. Now it's 7200, but I tweaked that encoder's settings, so I can see that change. But sometimes, at random, it'll overflow a WORD 4 or 5 times @ full travel. That's a far cry from 3600 or 7200! And the kicker is, I do not think it's the encoder. When it would do this, I am watching it on a scope, and there would be zero change. Same PW and freq as it always has been.
PIC16F1829

Code:

'**************************************************************** '* Name : UNTITLED.BAS * '* Author : [select VIEW...EDITOR OPTIONS] * '* Notice : Copyright (c) 2014 [select VIEW...EDITOR OPTIONS] * '* : All Rights Reserved * '* Date : 6/7/2014 * '* Version : 1.0 * '* Notes : * '* : * '**************************************************************** INCLUDE "DT_INTS-14.bas" INCLUDE "ReEnterPBP.bas" DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive DEFINE HSER_TXSTA 24h ' Enable transmit, BRGH = 1 DEFINE HSER_SPBRG 129 ' 9600 Baud @ 20MHz, 0.16% DEFINE HSER_CLROERR 1 ' Clear overflow automatically APFCON0.2 = 1 APFCON0.7 = 1 OPTION_REG.6 = 1 #CONFIG __config _CONFIG1, _FOSC_HS & _WDTE_OFF & _PWRTE_OFF & _MCLRE_ON & _CP_OFF & _CPD_OFF & _BOREN_OFF & _CLKOUTEN_OFF & _IESO_OFF __config _CONFIG2, _PLLEN_OFF & _LVP_OFF #ENDCONFIG DEFINE OSC 20 ANSELA = 0 ANSELB = 0 ANSELC = 0 DEFINE LCD_DREG PORTB DEFINE LCD_DBIT 4 DEFINE LCD_RSREG PORTA DEFINE LCD_RSBIT 0 DEFINE LCD_EREG PORTA DEFINE LCD_EBIT 1 DEFINE LCD_BITS 4 DEFINE LCD_LINES 2 DEFINE LCD_COMMANDUS 1500 DEFINE LCD_DATAUS 44 LED var PORTC.7 high LED ASM INT_LIST macro ; IntSource, Label, Type, ResetFlag? INT_Handler INT_INT, _doEncoder, PBP, yes endm INT_CREATE ; Creates the interrupt processor ENDASM @ INT_ENABLE INT_INT stowlight var byte stowlight = 1 TRISC.6 = 1 DOWN var PORTC.1 TRISC.1 = 0 DOWN = 0 EAST var PORTC.2 TRISC.2 = 0 EAST = 0 WEST var PORTC.5 TRISC.5 = 0 WEST = 0 UP var PORTC.0 TRISC.0 = 0 UP = 0 RX var PORTC.6 TRISC.6 = 1 a0 var byte a1 var byte e0 var byte e1 var byte i var byte VerboseMode var byte cereal var byte Aencoder0Pos var word Eencoder0Pos var word HEL var byte HAZ var byte oldpos var word newpos var word distance var word Eoldposition var word Enewposition var word stowed var byte apple var byte SatLocEl var word SatLocEl = 6837 SatLocAz var word SatLocAz = 52198 VerboseMode = 0 goto startup doEncoder: if UP = 1 then ' if e0 = 10 then Eencoder0Pos = Eencoder0Pos + 1 ' e0 = 0 lcdout $FE, $01, "EL= ", #Eencoder0Pos lcdout $FE, $C0, "AZ= ", #Aencoder0Pos ' endif ' e0 = e0 + 1 endif if down = 1 then ' if e1 = 10 then Eencoder0Pos = Eencoder0Pos - 1 ' e1 = 0 lcdout $FE, $01, "EL= ", #Eencoder0Pos lcdout $FE, $C0, "AZ= ", #Aencoder0Pos ' endif e1 = e1 + 1 endif if EAST = 1 then if a0 = 5 then Aencoder0Pos = Aencoder0Pos - 1 A0 = 0 lcdout $FE, $01, "EL= ", #Eencoder0Pos lcdout $FE, $C0, "AZ= ", #Aencoder0Pos endif a0 = a0 + 1 endif if WEST = 1 then if a1 = 5 then Aencoder0Pos = Aencoder0Pos + 1 a1 = 0 lcdout $FE, $01, "EL= ", #Eencoder0Pos lcdout $FE, $C0, "AZ= ", #Aencoder0Pos endif a1 = a1 + 1 endif @ INT_RETURN Startup: gosub CLR hserout ["Running Startup Procedures!", 13, 10] hserout ["PLEASE WAIT....", 13, 10] pause 3000 Eencoder0Pos = 0 Eoldposition = Eencoder0Pos DOWN = 1 pause 1000 gosub allSTOP Enewposition = Eencoder0Pos IF Eoldposition = Enewposition THEN stowed = 1 apple = 1 Eencoder0Pos = 0 Aencoder0Pos = 40000 gosub CLR hserout ["Startup Sequence Good!", 13, 10] hserout ["Continuing to Main Menu...", 13, 10] pause 5000 goto MainMenu ENDIF IF Enewposition <> Eoldposition THEN stowed = 0 apple = 1 UP = 1 pause 1000 gosub allSTOP gosub CLR hserout ["Startup Error!", 13, 10] hserout ["Dish will need homing before move will be allowed!", 13, 10] hserout ["Continuing to Main Menu...", 13, 10] pause 5000 goto Mainmenu ENDIF MainMenu: gosub CLR HSEROUT ["******** MAIN MENU ********", 13, 10, 10] HSEROUT [" 1. Start Homing Sequence", 13, 10] HSEROUT [" 2. Manual JOG Mode", 13, 10] HSEROUT [" 3. Auto-Acquire Satellite", 13, 10] HSEROUT [" 4. Stow Dish for Travel", 13, 10, 10] HSEROUT ["Enter Your Selection:",13,10] SERIN RX, 2, cereal if VerboseMode = 1 then HSEROUT [#cereal,13,10] If cereal = "1" then goto HomeDish If cereal = "2" then if apple = 1 then goto JogMenu if apple <> 1 then gosub ForceHome endif If cereal = "3" then if apple = 1 then goto RoughAcquire if apple <> 1 then gosub ForceHome endif If cereal = "4" then if apple = 1 then goto StowMenu if apple <> 1 then gosub ForceHome endif goto MainMenu RoughAcquire: if Eencoder0Pos < 7000 then UP = 1 uploop1: pause 100 if Eencoder0Pos < 7000 then goto uploop1 gosub allSTOP endif If Aencoder0Pos < SatLocAz then WEST = 1 azloop1: pause 100 if Aencoder0Pos < SatLocAz then goto azloop1 gosub allSTOP elseif Aencoder0Pos > SatLocAz then EAST = 1 azloop2: pause 100 if Aencoder0Pos > SatLocAz then goto azloop2 gosub allSTOP endif If Eencoder0Pos > SatLocEl then DOWN = 1 dnloop1: pause 100 if Eencoder0Pos > SatLocEl then goto dnloop1 gosub allSTOP endif goto MainMenu HomeDish: gosub CLR hserout ["******** HOME DISH ********", 13, 10, 10] hserout [" 1. Start Homing Sequence", 13, 10, 10] hserout [" 2 Abort Homing", 13, 10, 10] hserout ["Enter Your Selection:"] serin RX, 2, cereal if cereal = "2" then goto MainMenu homeloop: IF cereal = "1" THEN HAZ = 0 HEL = 0 gosub HomeEL gosub HomeAZ 'Haz = 1 IF (HEL = 1) AND (HAZ = 1) THEN gosub clr hserout ["HOME PROCESS WAS SUCCESSFUL!", 13, 10] apple = 1 goto MainMenu ENDIF IF (HEL = 0) OR (HAZ = 0 ) THEN gosub clr hserout ["DIS HOME PROCESS CAN SUCK MY DICK!", 13, 10] goto MainMenu ENDIF ENDIF pause(200) if cereal <> "1" then goto HomeDish goto homeloop goto HomeDish HomeAZ: gosub clr hserout ["HOMING AZIMUTH - PLEASE WAIT..", 13, 10] PAUSE(500) Aencoder0Pos = 0 oldpos = 0 WEST = 1 PAUSE(250) IF Aencoder0Pos = 0 THEN gosub allSTOP EAST = 1 PAUSE(250) gosub allSTOP PAUSE(500) Aencoder0Pos = 0 WEST = 1 PAUSE(500) IF Aencoder0Pos = 0 THEN goto moveerror ENDIF pause 1000 loop4: pause 250 oldpos = newpos newpos = Aencoder0POS if oldpos > newpos then distance = oldpos - newpos hserout ["oldpos = ", #oldpos, " newpos = ", #newpos, " --- Distance = ", #distance, 13, 10] endif if newpos > oldpos then distance = newpos - oldpos hserout ["newpos = ", #newpos, " oldpos = ", #oldpos, " --- Distance = ", #distance, 13, 10] endif if (oldpos = newpos) and (oldpos <> 0) then distance = 0 if (distance < 5) or (distance > 500) then gosub allSTOP Aencoder0Pos = 54000 newpos = Aencoder0POS hserout ["HOMING AZIMUTH WAS SUCCESSFUL!", 13, 10] HAZ = 1 endif IF HAZ = 0 THEN goto loop4 EAST = 1 loop8: pause 100 hserout ["Aencoder0Pos = ", #Aencoder0Pos, 13, 10] if Aencoder0Pos > 50000 then GOTO LOOP8 GOSUB allSTOP return HomeEL: gosub CLR hserout ["HOMING ELEVATION - PLEASE WAIT..", 13, 10] PAUSE(500) Eencoder0Pos = 0 UP = 1 PAUSE(250) IF Eencoder0Pos = 0 THEN gosub allSTOP DOWN = 1 PAUSE(250) gosub allSTOP PAUSE(500) Eencoder0Pos = 0 UP = 1 PAUSE(500) IF Eencoder0Pos = 0 THEN goto moveerror ENDIF pause 1000 loop1: pause 250 oldpos = newpos newpos = Eencoder0POS if oldpos > newpos then distance = oldpos - newpos if newpos > oldpos then distance = newpos - oldpos if oldpos = newpos then distance = 0 if distance < 5 then gosub allSTOP Eencoder0Pos = 7220 newpos = Eencoder0POS hserout ["HOMING ELEVATION WAS SUCCESSFUL!", 13, 10] HEL = 1 endif IF HEL = 0 THEN goto loop1 DOWN = 1 loop2: pause 100 'hserout ["Eencoder0Pos = ", #Eencoder0Pos, 13, 10] if Eencoder0Pos > 7000 then GOTO loop2 oldpos = 0 newpos = 0 GOSUB allSTOP return StowMenu: gosub CLR hserout ["******** STOW DISH ********", 13, 10, 10] hserout [" 1. Start STOW Sequence", 13, 10, 10] hserout [" 2 Abort STOW", 13, 10, 10] hserout ["Enter Your Selection:"] serin RX, 2, cereal if cereal = "2" then goto MainMenu if (cereal = "1") and (apple = 1) and (stowed <> 1) then goto StowDish goto moveerror StowDish: gosub CLR hserout ["***** PLEASE WAIT ******", 13, 10] if Eencoder0Pos < 5500 then UP = 1 loop3: pause 250 if Eencoder0Pos < 5500 then goto loop3 gosub allSTOP endif If Aencoder0Pos > 40000 then east = 1 loop5: pause 250 if Aencoder0Pos > 40000 then goto loop5 gosub allSTOP elseif Aencoder0Pos < 40000 then WEST = 1 loop6: pause 250 if Aencoder0Pos < 40000 then goto loop6 gosub allSTOP endif If stowlight = 1 then down = 1 loop7: pause 250 oldpos = newpos newpos = Eencoder0POS distance = oldpos - newpos if (Eencoder0Pos > 0) and (distance <> 0) then goto loop7 gosub allSTOP elseif stowlight <> 1 then gosub moveerror gosub forcehome apple = 0 endif goto mainmenu JogMenu: gosub CLR pause 250 HSEROUT ["***** JOG MENU *****", 13, 10, 10] HSEROUT ["U - UP", 13, 10] HSEROUT ["D - DOWN", 13, 10] HSEROUT ["E - EAST", 13, 10] HSEROUT ["W - WEST", 13, 10] HSEROUT ["S - ALL STOP", 13, 10] HSEROUT ["X - MAIN MENU", 13, 10, 10] SERIN RX, 2, cereal IF cereal = "A" then Eencoder0Pos = 0 if cereal = "B" then Aencoder0Pos = 0 if cereal = "U" Then gosub allSTOP UP = 1 endif if cereal = "D" then gosub allSTOP DOWN = 1 endif if cereal = "E" then gosub allSTOP EAST = 1 endif if cereal = "W" then gosub allSTOP WEST = 1 endif if cereal = "S" then gosub allSTOP if cereal = "X" then gosub allSTOP goto MainMenu endif goto JOGMenu allSTOP: EAST = 0 UP = 0 DOWN = 0 WEST = 0 if VerboseMode = 1 then GOSUB POS return CLR: if VerboseMode = 0 then For i = 0 to 30 HSEROUT [10] next i endif return abort: gosub allSTOP gosub clr HSEROUT ["USER STOP! -- MOVE ABORTED!", 13, 10] PAUSE(5000) goto MainMenu ForceHome: gosub CLR hserout ["SYSTEM ERROR!", 13, 10] hserout ["SYSTEM'S HOMING COORDINATES NOT SET!", 13, 10] hserout ["SYSTEM CANNOT BE MOVED UNTIL HOMING IS PERFORMED!", 13, 10] pause 7000 return moveerror: gosub allSTOP gosub clr HSEROUT ["SYSTEM ERROR! -- MOVE ABORTED!", 13, 10] PAUSE(5000) goto MainMenu POS: lcdout $FE, $01, "EL= ", #Eencoder0Pos lcdout $FE, $C0, "AZ= ", #Aencoder0Pos return

Re: Semi-random INT count???

most satellite positioner encoders are a reed switch operated by a multipole disc magnet , you have two encoders sharing one interrupt . what happens if one positioner stops with the reed closed ,wont that lead to lost impulses for the other encoder ?
as has been discussed before when you have a multi-byte variable that's altered in a interrupt routine its true value is indeterminate while the isr is active .
the correct procedure to access the var is to
disable isr
examine var (copy compare or whatever)
enable isr

Re: Semi-random INT count???

Ok... These are quadrature encoders. Each one has two signal wires producing a dual square wave at 50% offset. Which one is first is dependent on which way the encoder is rotating. I am only using one signal wire from each encoder. There will be three. Right now there are only two... Elevation and Azimuth. I have the chip and BT module inside on my breadboard temporarily. The encoders DID join outside onto one wire, but due to growing concerns as to what happens when the unused encoder is in an "other than floating" position, I separated them all the way to the breadboard. They still go into the PIC on just one leg, but are physically separated by a SPDT relay now. I will re-code and put them to their own leg in the end, but at the moment, the relay seems sufficient to separate them so as to eliminate that as the cause of this problem.

It's really baffling to me how I can be looking at the exact same pattern on the scope, and yet the PIC is reading an ENTIRELY different thing. To go from ~7500 pulses from end to end, all the way to 300,000 to 400,000 pulses would cause a MAJOR difference that I just couldn't mistake on the scope, and it's just not the case... it looks like no change at all, but the number count is insanely different.

Re: Semi-random INT count???

Quote:

Originally Posted by richard

as has been discussed before when you have a multi-byte variable that's altered in a interrupt routine its true value is indeterminate while the isr is active .
the correct procedure to access the var is to
disable isr
examine var (copy compare or whatever)
enable isr

I'm unfamiliar with this black magic you speak of... tell me more...

Re: Semi-random INT count???

lets have a word var count and a word var pos
count is the one used in your isr , pos will be the " current " position outside the isr

we have a sub to get pos
getpos:

@ INT_DISABLE INT_INT
POS= COUNT
@ INT_ENABLE INT_INT
RETURN

now whenever you wish to use pos just call getpos first to "refresh" its value

some more thoughts
1 are your encoders mechanically switched ( ie contact bounce could be an issue)
2 isr's should be kept as short a possible , lcd routines in isr may cause unexpected issues
3 have you tesed with only one encoder is connected ?
4 have you a schematic of your setup and a link to the positioner encoder data sheet

Re: Semi-random INT count???

Hi,
A schematic would be nice but I think we've covered this before. Two encoder signals on the same pin, fighting each other, is most likely not a good solution. You mention a relay, switching between the two, and that should be fine. Just make sure the signal at the PIC input is well defined (pulled up/down) and not floating at any point.

And Richard is spot on. If the frequeuncy of the encoder signal is anything above "a couple of Hz" you definitely do not want the LCDOUT statements within the ISR. Those two statments takes at least 5ms to exectute, then there's the rest of the ISR itself (which isn't much but still...) and the system variable save/restore. But let's say 5ms (and that's probably on the LOW side) then your input frequency can't be higher than 200Hz.

If you have a two channel scope you can test this.
1) Scope the input signal to the PIC with channel 1 on the scope.
2) Set a pin high at the beginning of the ISR. Set it LOW at the end of the ISR.
3) Scope this output of this pin with channel 2 on the scope.

The time between the rising edge on Ch1 and the rising edge on Ch2 is the interrupt latency, the time it takes to save the system vars and "get to" the actual ISR code.
The pulse width on Ch2 is the execution time of the ISR itself.
Then there's the time it takes to restore the system vars and "get out" of the ISR. This is pretty much equal to the measured latency.

Add the numbers together, ie 2*latency + ISR execution time and see what you get. Make sure you do this with a LOW(ish) input frequency to ENSURE you're not "overrunning" yourself. Then remove the LCDOUT statements from the ISR and measure again.

/Henrik.

Re: Semi-random INT count???

OK, bummer! My debugging was buggy.... Those are only there for the moment to see where I am. My fastest encoder, according to the scope is running about 50-60 hz. So that may be the problem. I'm headed out the door, but I'll try to deal with it when I get back this afternoon and see how it goes. I am still skeptical though, since it was the slow encoder that first showed the problem, and I still cant see how it would go from 3500 counts in say 120 seconds, all the way up to multiple WORD stackoverflows in the same time from this issue, but maybe I just still dont see the big picture....