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RA2 is set as an input by the tris register, so the impeadence is relativly high, your meter MAY be enough load to reduce the voltage read, install a pull up resistor from RA2 to VDD to bring it up to the 5v level or enable WPUA (sect 4.3) data sheet.Originally Posted by jellis00
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COUNT is not counting again
Joe, I enabled a WPUA.2 = 1 on RA2. However, with this change the voltage on RA2 when open circuit output is still at 3.2 vdc rather than Vih or close to Vdd. My code now looks like below. Interestingly the WRITE 7, TMR0 in the IF block never shows a value other than zero. However, just a couple of momentary switch activations will enter into the ELSE block where the WRITE 9, TRM0 statement shows a value of greater than K each time. So it looks like a lot of switch bounce going on, but the thing I don't understand is why the WRITE 7, TMR0 statement isn't showing any TMR0 values< K.
I also notice that if I comment out the LED blink statements in the IF block, the WRITE 7 statement doesn't write anything because the memory address shows a continuous FF value. Strange things that I don't understand. But at least it looks like the TMR0 is counting whether the value shows up correctly or not.
Tomorrow I am going to try to generate another method of simulating the external sensor input pulses to eliminate the switch bounce problem. I thought this might be possible by using one of the I/O pin outputs in a similar blink sequence loop as I am using for the LED, and then route that output into RA2. Do you think this would work? I will try to use one of the I/O pins that has a CMOS output.
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COUNT is not counting again
This time with the code:
Code:@ __config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF & _CP_OFF K CON 15 ' Calibration factor for flow meter = # pulses per gal ' Setup Timer0 as an 8-bit counter with the clock input on RA2. ' 1:1 TMR0 prescaler ' TMR0 counts on high-to-low transitions OPTION_REG = %00111000 ' A/D & Comparators disabled ANSEL=0 ' all digital ANSELH=0 ' analog module disabled CM1CON0=0 CM2CON0=0 ' Port setup PORTC = 0 ' LEDs off, PULSOUT RC3 provides a high-going pulse PORTA = 0 TRISC = %11110000 ' lower 4 pins outputs TRISA = %11111111 ' RA2 = 2TMR0 clock input for simulated meter pulse inputs TMR0 = 0 ' clear TMR0 count WPUA.2 = 1 ' enable weak pull-up on RA2 Main: IF TMR0 < K THEN WRITE 7, TMR0 ' write count during testing ' Keep the valve open...do nothing..let water flow HIGH PORTC.0 ' Blink Light LED while water is flowing Pause 500 LOW PORTC.0 PAUSE 500 ELSE WRITE 9, TMR0 ' write count during testing before clearing TMR0 = 0 ' clear TMR0 count PULSOUT PORTC.3,1000 ' Generate required 10 msec pulse to RC3 ENDIF GOTO Main END
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try masking the interrupt just before write and reenable right after.
Code:eecon1 = 6 ' enables eeprom write intcon.7 = 1 write address, data intcon.7 =0
Last edited by Archangel; - 8th May 2009 at 10:35.
If you do not believe in MAGIC, Consider how currency has value simply by printing it, and is then traded for real assets.
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Gold is the money of kings, silver is the money of gentlemen, barter is the money of peasants - but debt is the money of slaves
.
There simply is no "Happy Spam" If you do it you will disappear from this forum.
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FYI, there's a new DEFINE for that
Code:DEFINE WRITE_INT 1
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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This code;
With the schematic attached - works. It writes 15 to EEPROM after preciselyCode:@ device pic16F690, intrc_osc_noclkout, wdt_off, mclr_off, protect_off K CON 15 ' Calibration factor for flow meter = # pulses per gal ' Setup Timer0 as an 8-bit counter with the clock input on RA2. ' 1:1 TMR0 prescaler ' TMR0 counts on high-to-low transitions OPTION_REG = %00111000 ' A/D & Comparators disabled ANSEL=0 ' all digital ANSELH=0 ' analog module disabled CM1CON0=0 CM2CON0=0 ' Port setup PORTC = 0 ' LEDs off, PULSOUT RC3 provides a high-going pulse PORTA = 0 TRISC = %11110000 ' lower 4 pins outputs TRISA = %11111111 ' RA2 = TMR0 clock input for simulated meter pulse inputs TMR0 = 0 ' clear TMR0 count Main: IF TMR0 < K THEN ' Keep the valve open...do nothing..let water flow ELSE PULSOUT PORTC.3,1000 ' Generate required 10 msec pulse to RC3 WRITE 7, TMR0 ' write count if you need to? TMR0 = 0 ' clear TMR0 count HIGH PORTC.0 ' LED toggle stuff PAUSE 500 LOW PORTC.0 ENDIF GOTO Main END
15 press/release actions on the switch.
Tested on the PICkit 2 low pin count demo board.
The cap on RA3 is 0.01uF, which helps eliminate contact bounce from the switch.
The switch on the PICkit 2 demo board connects to RA3, so a wire runs directly from
RA3 to RA2. Remove the cap, and switch bounce causes problems. It's a really simple
fix.
If your circuit is powered from 5V, and you measure 5V between the PIC VDD/VSS pins,
and you only see 3.2V on RA2 with a pull-up to VDD, then check your circuit. There's a
problem somewhere with your wiring or connections.
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COUNT is not counting again
I don't see this DEFINE listed in Appendix B of the PICBASIC PRO manual, which supposedly lists all DEFINEs.
Can you explain how you would use this to replace the code statements Joe lists to mask interrupts while writing? Do you just precede the WRITE statement with DEFINE WRITE_INT1? After the WRITE, do you still have to re-enable the interrupt? I guess if you have to do all this, I don't see how it is any more efficient than using Joe's 4 statements.
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If DEFINE WRITE_INT isn't in your manual, then you probably have an older version of PBP
or an old manual before this new define option was added.
Newer versions of PBP include a check for this in the WRITE library. If you have DEFINE
WRITE_INT 1 declared, it automatically disables interrupts before the write, and re-enables
interrupts immediately after the write is complete.
It just saves you from having to remember to do it yourself.
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That should save someone some brain damage. Where did you learn that? Das Book ?
Credit to where credit is due . . . BRUCE . . . always on target.Joe S., the 0.01 uF capacitor definitely solved my switch bounce problem. The code now works perfectly and always counts exactly 15 pulses when it activates the external pulse to the valve solenoid.Maybe not more efficient, but way easier.After the WRITE, do you still have to re-enable the interrupt? I guess if you have to do all this, I don't see how it is any more efficient than using Joe's 4 statements.
Last edited by Archangel; - 8th May 2009 at 20:17.
If you do not believe in MAGIC, Consider how currency has value simply by printing it, and is then traded for real assets.
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Gold is the money of kings, silver is the money of gentlemen, barter is the money of peasants - but debt is the money of slaves
.
There simply is no "Happy Spam" If you do it you will disappear from this forum.
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Now same working code won't work with PCB Pro??
I thought I had this problem licked. Then I purchased PCB PRO and tried to run the same code that ran in PCB. I get all an "Overwriting prrevious address contents" assembly error and many "Symbol not previously defined erros" as related to the ANSEL, ANSELH, CM1CON and CM2CON statements as shown in the attached image. These errors sort of sound like a problem with the CONFIG statement not being commented out in the .inc file. I did make sure I commented out the @ __device statement in the 16F690.incl file that came with PCB PRO so it isn't overwritten by the !__config statement in the code.
Can't figure thwhy this code now won't assemble. Can any of you advise me why my code would run in PCB and won't assemble in PCB PRO??
Here is the current code as adapted from Bruce's "Non-Interrupt version" in his above post.
Code:@ __config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF & _CP_OFF i var Byte ' Indexer for use in For..Next loop K CON 15 ' Calibration factor for flow meter = # pulses per gal ' Setup Timer0 as an 8-bit counter with the clock input on RA2. ' 1:1 TMR0 prescaler ' TMR0 counts on high-to-low transitions OPTION_REG = %00111000 ' A/D & Comparators disabled ANSEL=0 ' all digital ANSELH=0 ' analog module disabled CM1CON0=0 CM2CON0=0 ' Port setup PORTA = 0 ' Clear the port register latches PORTB = 0 PORTC = 0 ' LEDs off, PULSOUT RC3 provides a high-going pulse ' Set or clear the data direction registers TRISA = %11111111 ' RA2 = TMR0 clock input for simulated meter pulse inputs TRISB = %11111111 TRISC = %11110000 ' lower 4 pins outputs 'VRCON = %00000000 ' turns the Vref Module OFF by clearing bit 7, 6, 4 TMR0 = 0 ' clear TMR0 count Main: IF TMR0 < K THEN ' Keep the valve open...do nothing..let water flow ELSE PULSOUT PORTC.3,1000 ' Generate required 10 msec pulse to RC3..close valve DEFINE WRITE_INT 1 WRITE 7, TMR0 ' write count if you need to during testing TMR0 = 0 ' Clear timer count For i = 1 to 3 ' Blink LED 3x to indicate valve turned off HIGH PORTC.0 PAUSE 500 LOW PORTC.0 Next ENDIF GOTO Main ' Loop to Main to wait for next meter flow input
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