12F683 - basic code not working

[Scampy]

Hi again,

I'm stumped on what's happening when I run the following code, and having gone over it time and time again I might be overlooking the obvious.

I have a motor connected to the H-bridge module that arrived yesterday - making pins 1 high and 2 low makes the motor run one way and reversing which pin is high and low makes the motor run the opposite way. I'm using a separate 9v supply for the motor.

When first turned on, the threshold set means that the code is set to night mode. I then shine a light on the LDR and the motor runs until I connect GPIO.5 to 5v to simulate the door closing the micro-switch at the end of its travel. So far so good. However, if I remove the connection between GPIO.5 and +5v to simulate the door in the close state GPIO.5 remains latched high. Grounding the pin momentarily has no affect, and disconnecting the H-bridge has no affect. Only way to clear this is to turn off and on the EasyPic5 board.

ASM
 __CONFIG _INTRC_OSC_NOCLKOUT & _WDT_ON & _PWRTE_ON & _MCLRE_OFF 
endasm

DEFINE ADC_BITS 10              ' ADC resolution
DEFINE ADC_CLOCK 3
DEFINE ADC_SAMPLEUS 50
number VAR word                 ' Variable to store ADC result
day var byte                    ' Variable to indicate day or night

CMCON0=7
CCP1CON=0
ANSEL = %00000001               ' GPIO.0 A/D in, rest digital
ADCON0.7 = 1                    ' Right justify for 10-bit
GPIO = %00000000                ' Initialize outputs
TRISIO = %101011                ' GPIO 0,1,3,5 = input, 2 & 4 outputs


Motor1          var gpio.2      ' H-Bridge pin 1
Motor2          var gpio.4      ' H-Bridge pin 2
SW1             VAR gpio.5      ' Door open limit switch


low sw1                         ' Ensure limit switch is 0 (door is closed)
low Motor1                      ' Turn off H-Bridge pin 1
low Motor2                      ' Turn off H-Bridge pin 2
day=0                           ' Initialise unit to check if day time

main:
if sw1=0 then day = 0           ' If limit switch is open, and mode is night then
adcin 0,number                  ' Read AN0
if day=0 then                   ' Day 0 = night, Day 1 = Day
  If number >660 then           ' If ACD result is above a threshold
  low SW1                       ' Set state of limit switch to off
  high Motor1                   ' Turn on H-Bridge pin 1
  Low Motor2                    ' Turn off H-Bridge pin 2
endif
endif
if SW1 = 1 then                 ' Door closes limit switch and applies 5v to GPIO.5
  low Motor1                    ' Turn off H-Bridge pin 1 }  Stop motor
  low Motor2                    ' Turn off H-Bridge pin 2 }
  day = 1                       ' Set variable to day to indicate the door is open
endif

goto main

The logic behind this project is that when the light level increases at dawn past the threshold it drives the motor which by use of a threaded rod slides open the door on the coop. When the door closes a micro-switch at the end of the travel the power to the motor is turned off and the unit placed in day mode. At the end of the day a switch will be pressed directly applying 5v to pin2 of the H-Bridge thus reversing the motor, opening the door and opening the switch, changing its state from 1 to 0.

Any ideas ??

Malcolm

[HenrikOlsson]

Hi,
First you configure GPIO.5 as an input by setting the TRISIO.5=1 - OK, that's fine since you're going to be monitoring a switch connected to that pin.
Then you set up an alias so that SW1 accesses GPIO.5 - perfectly fine.
Then you go and do LOW SW1 - which turns the GPIO.5 into an output and pulls it low - not OK, the pin is no longer an input so it can't read the state of the switch.

Keep GPIO.5 as an input and make sure it has a pullup resistor to Vcc if the switch pulls it low or a pulldown resistor do Vss if the switch pulls it high.

/Henrik.

[Scampy]

Cheers Henrik,

I've removed all reference to SW1 =1 or LOW SW1 and it now no longer latches. - Thank you.

Now to actually turn this into a working door

[Scampy]

I've been playing about with the code and have now tested it on the development board over and over again, simulating the process of the door actuator being manually closed, and then opened triggered by the increasing light levels at dawn. Next step will be to transfer the PIC to a bit of strip board and add the regulators etc and then test it for real and monitor the current drawn to close the door on the coop. I plan on using a motorcycle battery 12v /4Ah which should be plenty. If funds permit I may add solar charging as a project at a later date.

Anyway, thanks guys for the assistance with this...

Malc

[AvionicsMaster1]

I did a project similar to this and had to account for something blocking door travel. I ended up with .1 ohm, I think, in series with the motor to monitor load by measuring the voltage across the resistor to determine current flow.

If motor is free running then current will be high initially but should be lower once friction and inertia are overcome. But if it's blocked/hampered/whatever the stall current will stay relatively high. I think I set it up to try to open and if blocked wait some time and then try again. Another ADC input if you've got a free port. Just a thought.

[Scampy]

Well that version of the project didn't work so well in the field...

I'm now working on a second version which uses a RTC. Basically I already have half the code written for one of my other projects so most of this will be a cut and paste. But something is really puzzling me and would welcome your advice.

I'm using a 16F690 (20 pin DIP) because it has both a basic UART and IC2 interface, and I happened to have a sample in my project box. I could be cleaver (yeah right) and use the full capabilities of the DS1307 and program the times for each month so it takes care of BST and GMT etc, but for now I thought the easiest way would be to use a serial utility to set the time and trigger value as required. Using PicMultiCalc to get the coms values I am able to connect and receive data, however the time is shown as 00:00 in the following code. Now like I mentioned , I've cut and pasted the section and same variables in a previous project so there should be no reason for it not to work. To prove the DS1307 is working on the breadboard (it hasn't been removed since I took a break from the previous project) I removed the 16F690 and replaced it with the 18F4580 and connected the jumper to the EasyPIC5 board - clock was displaying the time set by the code. Noted the correct clk and dta pins, powered down the EP5 board and mapped the connections to the pins used by the 16F690. Replaced the 16F690 and tested again - the serial monitor in Microcode Studio connected and displayed "Time : 00:00"

I've looked at the data sheet, but not sure if I am missing anything (probably some register needs setting but I'll be dammed if I can see it) so hopefully someone here might be able to assist.

Here's the code

'****************************************************************
'*  Name    : Chicken Coop Door Control                         *
'*  Author  : Malcolm Crabbe                                    *
'*  Date    : 30th January 2014                                 *
'*  Version : 1.0                                               *
'*  Notes   : Uses PBP 2.60c                                    *
'*          : 16F690, int osc 4MHz                              *
'*          : Program uses RTC  to turn                         *
'*          : on an electric motor and open a sliding door.     *
'*          : Door travel controlled by limit switches          *
'****************************************************************


ASM
 __CONFIG _INTRC_OSC_NOCLKOUT & _WDT_ON & _PWRTE_ON & _MCLRE_OFF  
endasm

ANSEL=%00000000
ADCON1=7
ADCON0 = %00000000                      'AD converter module disabled
ADCON1 = %00001111 

TRISA=%00000011                         'set PORTA as all output 
TRISC=%00000001                         'set PORTC as all output apart from RC0
TRISB=%00000011

DEFINE HSER_RCSTA 90h                   'Enable serial port & continuous receive
DEFINE HSER_TXSTA 24h                   'Enable transmit, BRGH = 1
DEFINE HSER_SPBRG 25                    '9600 Baud @ 0.16%
DEFINE HSER_CLROERR 1                   'Clear overflow automatically

day             var byte 
RTCMin          var byte		        'RTC Minutes
RTCHour         var byte	            'RTC Hours
RTCsec          var byte                'RTC Seconds

TimeH           var byte                'variable to store Hours
TimeM           var byte                'variable to store Minutes
SS              VAR Byte                'variable to store Seconds

CounterA        var byte	            'General purpose Variable
CounterB        var byte	            'General purpose Variable

Counter1        var word                'used to store the current time as a digit.  Counts minutes from 0000 at midnight (to be added later)

Relay           var PortA.5             'used to activate relay and thus reverse direction
Motor           var PortA.4             'used to drive the motor
SW1             VAR PortA.0             'Door open limit switch
SW2             VAR PortA.1             'Door closed limit switch
Tx              var PortB.7             'used for sending time value in testing
Rx              Var PortB.5             'used for receiving time value in testing

SetMN           var byte		        'Used to set time Minutes
SetHR           var byte	            'Used to set time Hours
SetSS           var byte                'Used to set time Seconds 

RCIF            VAR PIR1.5              'USART receive flag
GIE             VAR INTCON.7
RCIF=1

SCLpin          var PORTB.6             'RTC pin - clk
SDApin          var PORTB.4             'RTC pin - data

setHR = 08                              'initial time to 8am 
setMN = 00

'convert initial time to BDC and write it to the DS1307
CounterA=SetMN
Gosub ConvertBCD
RTCMin=CounterB

CounterA=SetHR
Gosub ConvertBCD
RTCHour=CounterB

I2Cwrite SDApin,SCLpin,$D0,$00,[RTCSec,RTCMin,RTCHour] 


test:

I2CREAD SDApin,SCLpin,$D0,$00,[RTCSec,RTCMin,RTCHour]  ; read DS1307 chip

timeH=(RTCHour>>4)                        'convert the BCD format of the hours register and store in variable timeH
timeH=(timeH &$03)*10
timeH=timeH+(RTCHour&$0F)

timeM=(RTCMin>>4)                         'convert the BCD format of the mins register and store in variable timeM
timeM=(timeM &$07)*10
timeM=timeM+(RTCMin&$0F)    

ss=(RTCSec>>4)                            'convert the BCD format of the sec register and store in variable ss
ss=(ss &$07)*10
ss=ss+(RTCSec&$0F)                     

Counter1 = (TimeH *60)+ TimeM             'take hours and multiply it by 60 then add odd minutes to get the total minutes into counter1

Hserout["Time: ",#TimeH DIG 1,#TimeH DIG 0,":",#TimeM DIG 1,#TimeM DIG 0,10]
pause 1000


goto test



'*******************************************************************************
' convert BDC format to decimal
 ConvertBCD:
	CounterB=CounterA DIG 1                        ' CounterA is the entry variable
	CounterB=CounterB<<4                           ' CounterB holds the converted BCD result on exit
	CounterB=CounterB+CounterA DIG 0
	Return
'*******************************************************************************

[AvionicsMaster1]

Well, just the first part of the post I'm not sure what state you want ADCON1 set to. Initially you have it set to 7 then 15. That one extra bit appears to significantly effect your ADC conversion cycle.

I also think you need to set OSCCON and put a DEFINE OSC ? in your code. I know the default is 4MHz but isn't the RC oscillator in your config the low low frequency oscillator? Could be wrong about that without reading further.

TRISA is only 6 ports and I think PBP starts with the LSB so you'll have bits 0 and 1 as input. TRISB doesn't look to have RB0 to RB3 so only 4 bits needed to set as output. TRISIC is indeed 8 bits but you've got TRISIC.0 set to input not as described in comments.

I don't often do serial so you'll have to let someone else chime in. I didn't look at rest of code. Hopefully I'm correct on at least one of these items and it will solve your problem.