12f675 to latch output while it does something else

[AVGuru]

My thinking is that flashing the LED pin affects the RELAY pin therefore they must be connected in some way.

it seems it is not possible to have 2 outputs HIGH at the same time....? i tried to lite up 2 leds:

HIGH LED1
HIGH LED2

only LED22 lights up, then i did:

HIGH LED1
PAUSE 1000
HIGH LED2

i see led1 light up (1s, as expected) then it goes off and led 2 lights up is there any LATCH ON command (maybe LATCH ON LED1) to set it high indefinitely led1 while we send another command to light up LED2....? how can we high LED1 until we send a LOW LED1, in the mean time we are doing other things like flash LED2, send IR/ RS232, etcetc..........?

I'm new at this please excuse some of my silly questions.

[Ioannis]

When LED2 is ON, does it stay ON for ever?

Ioannis

[AVGuru]

When LED2 is ON, does it stay ON for ever?

Ioannis

yes that does. I initially thought maybe there was a problem with the out put pin., i swap to other pins, same result, still not satisfied, i ran my scope on the the pins, yup, th efirst led switches ON briefly and then OFF as the second led lights up.

hhhhhmmmmmmmmmm (rubbing chin........) how do i get it to stay ON..............?

[Ioannis]

OK, this is not logic at all.

Please post all the test code that you used to light the two led's.

There is something that we are missing here.

Ioannis

[AVGuru]

OK, this is not logic at all.

Please post all the test code that you used to light the two led's.

There is something that we are missing here.

Ioannis

Standby: 'WAIT FOR BUTTON TO STARTUP
Button SWITCH,1,255,0,b1,1,STARTUP 'Check Button 1 (Skip to heartbeat if Not Pressed)

Heartbeat:
'HEART BEAT INDICATOR ON LED
For DUTYCYCLE = 0 to 255 STEP 3 'THIS IS THE DELAY 255 MAX. COUNT LESS FASTER
PWM LED, DUTYCYCLE, 1 'THE NUMBER WILL DETERMINE SPEED SMALLER FASTER
Next
For DUTYCYCLE = 255 to 0 Step -2
PWM LED, DUTYCYCLE, 1 'THE NUMBER WILL DETERMINE SPEED SMALLER FASTER
Next

GOTO STANDBY


startup:

HIGH relay ' SWITCH ON POWER TO PROJECTOR
' OPTION TO SEND IR TO PROJECTOR
' OPTION TO SEND RS232 TO PROJECTOR

'TESTING WITH TIME =20
FOR TIMES = 20 TO 1 STEP -1 '1m FOR PROJECTOR WARMUP
HIGH LED 'INDICATOR FOR SYSTEM START-UP
PAUSE 250 'INDICATOR FOR SYSTEM START-UP
LOW LED 'INDICATOR FOR SYSTEM START-UP
PAUSE 250 'INDICATOR FOR SYSTEM START-UP
NEXT TIMES


running: 'WAIT FOR INTERUPT TO SHUTDOWN
Button SWITCH,1,255,0,B1,1,SHUTDOWN 'Check Button 1 (Skip to ledup if Not Pressed)
'SHUTDOWN IF BUTTON IS PRESSED
ledup:
HIGH LED 'INDICATOR FOR SYSTEM RUNNING
GOTO RUNNING 'LOOP UNTIL BUTTON IS PRESSED



shutdown:

' OPTION TO SEND IR TO PROJECTOR
' OPTION TO SEND RS232 TO PROJECTOR
'TESTING WITH TIME =20
FOR TIMES = 20 TO 1 STEP -1 '120s (2m) FOR PROJECTOR COOLDOWN
HIGH LED 'INDICATOR FOR SYSTEM START-UP
PAUSE 250 'INDICATOR FOR SYSTEM START-UP
LOW LED 'INDICATOR FOR SYSTEM START-UP
PAUSE 250
NEXT TIMES
LOW RELAY 'SHUT OFF POWER TO PROJECTOR

GOTO STANDBY

END

you see I'm tring to create a delay power switch, to allow for projector to cool down before the power is cut off. normally in my office, they just hit the power button on the remote control and throw the switch as they leave the room, usually done in the same breath. i want to create a delay so.... the power will be cut off only after 2m, to allow for cooling of the lamp, this will make the lamp last longer before the next change is required.
so here we have 3 states:
standby: power realy is OFF, LED gives a heartbeat light
startup: power relay is ON, LED Flashes for 30s (does not allow you to switch OFF the power)
running: power relay is ON, LED is ON
shutdown: LED flashes (2m to allow cooling) relay OFF
go to standby wait for next cycle

very simple requirement, but I cannot get the relay to go 'ON' at the same time LED to go "ON"

[HenrikOlsson]

Hi,

it seems it is not possible to have 2 outputs HIGH at the same time....? i tried to lite up 2 leds:

Sounds like you're getting bit by the ever so clasic read-modify-write issue caused by not having analog functionallity on related pins turned off.

CMCON = 7   ' Turn off comparator on 12F675
ANSEL = 0    ' None of the I/O connected to the ADC

/Henrik.

[Ioannis]

What Henrik stated must be placed on top of your program.

Try it and reply the results.

Ioannis

[AVGuru]

Thanks henrik, Ill try that on Monday. Have a great weekend..!

Philip

[AVGuru]

Hi,


Sounds like you're getting bit by the ever so clasic read-modify-write issue caused by not having analog functionallity on related pins turned off.

CMCON = 7   ' Turn off comparator on 12F675
ANSEL = 0    ' None of the I/O connected to the ADC

/Henrik.

Henrik, thanks a million, we managed to get it to work. Alto port 1 out does not light the led. It ok I already know why. I can't see how I missed out the config for comparator. Thanks again....!

[Amoque]

How do i get it to stay ON..............?

I don't think there's anything of substance I can add here, only chiming in to answer implicitly: There is no command or statement to make a pin or port "stay" on. Pin states are "set and forget" in that they go high or low only as commanded - and remain so, until commanded to change. Some statements include changing input/ output or high/ low as part of the assembly (documented), but port state is a switch and commanded - at some level.

So, for anyone following on after looking for a solution to a similar problem: check your code, check your configuration, check your power supply; the pin will remain set (or cleared) as initially commanded unless some other influence holds sway.

[mark_s]

In addition to what others suggested. Are you using a transistor to buffer the pic
output from the relay coil? If not you may be exceeding the current capacity of
the output pin. This could cause heating and result in the pic resetting. Also inductive
voltage spikes can cause resets. A simple schematic would help of your relay connection.

[AVGuru]

In addition to what others suggested. Are you using a transistor to buffer the pic
output from the relay coil? If not you may be exceeding the current capacity of
the output pin. This could cause heating and result in the pic resetting. Also inductive
voltage spikes can cause resets. A simple schematic would help of your relay connection.

Hi mark, thanks for the heads up on that, Yes I'm using a 2N2222 for the output to relay on open emitter, as well as a diode across the relay to stop it from chattering.

[HenrikOlsson]

Hi,

Hi henrik, I seem to have lost A.0 & A.1 & A.3 as outputs....? I tried to swap the led around the port, but they won't light up.

Not sure I understand what this means.
On the 12F675 you have GPIO.0 etc. Make sure you reference that and make sure you set/clear TRISIO accordingly.

/Henrik.

[AVGuru]

Hi mark, thanks for the heads up on that, Yes I'm using a 2N2222 for the output to relay on open emitter, as well as a diode across the relay to stop it from chattering.

THANK YOU all. got it to work on the PICEASY board, now to put it in a box and on the wall.


thanks again