12F683 - basic code not working

[Scampy]

Fit a 1k-2k resistor then verify the operation in steps.
1) Measure the voltage at the PIC output, it should be either 0 or 5V (or close to it). If it's not then something is wrong.
2) Measure the voltage at the base of transistor, it should be either 0 or 0.6V (or close to it). If it's not something is wrong.
3) Measure the voltage at the collector of the transistor, it should be 5V when the transitor is OFF and close to 0 when the transitor is ON.

If it doesn't work please do the above measurments and report the results.

/Henrik.

Fitted a 1.5K resistor

1) - Voltage out when the pin goes high = 4.52v
2) - Base of transistor voltage measured 0.73v
3) - Voltage at collector when PIC pin was HIGH was 0.03v and 5.01v when PIC pin was LOW

Still the relay contacts didn't switch.

Thinking it might be the regulator as I'm using a 200mA version of the 7805 I changed this for a traditional 1 amp version - still no change.

As the new relays are DIL footprint (16 pin DIL) and I am using sockets, I removed the relays and inserted the pins of the original relay into the contacts on the DIL socket. This relay also has a coil of 68 ohms so would be drawing similar current of around 80mA ? - The contacts changed over just fine. Last test was to attach two wires to the coil and plug this into the DIL socket - still no change, but plugging the coil directly across the 5v switched it hard...

I'm going to re-breadboard the hardware with the DIL relays and see if it switches OK just to rule out a fault on the stripboard (my eyes are not what they used to be - so I could have a dry joint or short somewhere !) - but I don't hold up much hope as any such issues should of resulted in the same thing happening with the original relay when tested with the stripboard.....

[Scampy]

Its now working.

I removed all the links to the relays apart from the coils - tested and it appeared to energise. I then googled the datasheet for the relays and found that the contacts where wired differently to the other relay (NO / NC then the comm rather then NO / comm / NC) - rewired the stripboard (now quite a mess) and it works (well I get 5v out to the motor when the pic energises the relays )

Thanks to all who contributed - and I'll note that formula for working out the resistances - Cheers Henrik

[Scampy]

Well for reference and to aid anyone who may stumble across this thread in future here's the circuit diagram and final code (full of comments to explain how it works)

'****************************************************************
'*  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

DEFINE  OSC 4
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

ANSEL  = %00000000                      'Set all pins digital
ANSELH = %00000000                      'Set all pins digital
ADCON0 = %00000000                      'AD converter module disabled
OSCCON = %01100101                      'bit7 not used, bits 6-4 4mhz default, bit3 int osc, bit2 HS stable (ignored - at 4Mhz), bit1 not stable, bit0 int osc used for system clk 
CCP1CON= %00000000                      'Turn off CCP module
SSPCON = %00001011                      'Ic2 master

TRISA=%00000111                         'set PORTA as all output apart from RA0, RA1 and RA2( bits 7&8 unimplimented read as 0)
TRISB=%11110000                         'set PORTB as all input ( bits 0-3 unimplimented read as 0)
TRISC=%11111111                         'set PORTC as all input (default for POR)

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
TempWD          VAR WORD

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

Char            var byte

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
SW3             var PortA.2             'Manual close button
Tx              var PortB.7             'used for sending time value in testing
Rx              Var PortB.5             'used for receiveing 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

onHR            var byte                'Used to set the Opening time (Hrs)
onMN            var byte                'Used to set the Opening time (Min)
Ontime          var word                'On time value in minutes

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 = 06                              'On powerup time set to 00 Hrs
setMN = 44                              'On powerup time set to 00 minutes

onHR = 06
onMN = 46

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

CounterA=SetHR
Gosub ConvertBCD
RTCHour=CounterB

I2Cwrite SDApin,SCLpin,$D0,$00,[RTCSec,RTCMin,RTCHour] 
day=0                                  ' set mode to night
low Motor                              ' set motor to off
low relay                              ' relay off


'*******************************************************************************
Main:
'*******************************************************************************

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
Ontime = (onHR*60)+onMN

Hserout["Time: ",#TimeH DIG 1,#TimeH DIG 0,":",#TimeM DIG 1,#TimeM DIG 0,":",#ss DIG 1,#ss DIG 0," Counter = ",#counter1," Ontime = ",#ontime,13,10]
pause 200
FOR TempWD = 0 TO 1000                           
        IF RCIF THEN GOto comms                  ' Check to see if there is communications on the comm port
        PauseUs 1000
NEXT TempWD

if counter1 = ontime and SW2=1 then              ' If counter matches on time and A.1 is high then 
  high Motor                                     ' Turn on the motor
  high relay                                     ' Energise the relay
endif
  
if SW1 = 1 then                                  ' Door open limit switch (A.0) hit and applies 5v to pin
  low Motor                                      ' Stop motor
  low relay                                      ' de-energise relay
endif

if ontime < counter1 or ontime > counter1 then   ' If the counter is anything other than ontime, turn everything off
  low SW1
  low motor                                      ' Turn on the motor
  low relay                                      ' Relay kept off for reverse polarity of motor
endif

If SW3 = 1 then
high motor
low relay
Low SW1 
endif

if SW2 = 1 and ontime < counter1 or ontime > counter1 then ' Door closed limit switch hit and applies 5v to pin
  low Motor                                      ' Stop motor
endif

goto Main
'*******************************************************************************
'*******************************************************************************
convert:
CounterA=SetMN
Gosub ConvertBCD
RTCMin=CounterB

CounterA=SetHR
Gosub ConvertBCD
RTCHour=CounterB

I2Cwrite SDApin,SCLpin,$D0,$00,[RTCSec,RTCMin,RTCHour] 
return
'*******************************************************************************
comms: 
HSERIN [Char]
SELECT CASE Char
        CASE "T","t"                            ' set time
hserout ["Set Time Hour ",10]    
HSERIN [#setHR]
hserout ["Set Time minutes ",10]
HSERIN [#setMN]
gosub convert

        CASE "O","o"        
Hserout["Set Open Time: ",13,10]
hserout ["Set Hour ",10]    
HSERIN [#onHR]
hserout ["Set Minutes ",10]
HSERIN [#onMN]
Ontime = (onHR*60)+onMN

        CASE "C","c" 
        Hserout["Time: ",#TimeH DIG 1,#TimeH DIG 0,":",#TimeM DIG 1,#TimeM DIG 0," Counter = ",#counter1,13,10]
pause 500
end select
goto Main

'*******************************************************************************
' 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
'*******************************************************************************

Ok the code may be very basic, could possibly be written tighter and isn't really rocket science, but it works for me. Likewise the choice of transistor in the schematic might of been better, but it's what I had and after the debuging - works with the relays etc.

I would like to thank all those who contributed to this thread and not only provided the support I needed, but also educated me both in PicBasic Pro and electronic component selection. - Thanks guys

Disclaimer:
The usual disclaimer applies, ie I accept no responsibility what-so-ever - anyone uses this code / schematic at their own risk etc etc... lardy dar de dar !! -- (sorry to high on pain killers for tooth ache !!)

[dw_picbasic]

Just for the fun of it, you may consider playing around with the relay and transistor separate from the PIC. There may be some possibility that a base bias resistor between 5k to 10K may actually switch that relay quite nicely. If so, that would put even less current demand on the output of the PIC. In the future if you are browsing a supplier like allelectronics, look for the 2n7000 N-Channel mosfet. It can handle 400mA and won't require any current at all from a PIC, since it is voltage driven. Just a 1 meg bias resistor holding the gate to ground. I bought a surplus box-of-em on ebay a while ago. Enough to last me the rest of my life ;-D

Great pics my friend!! and a very well done project!!
Congrats!!
Duane :-]