3 month countdown alarm (miniature circuit)

Thread Starter

MLD

Joined Dec 7, 2012
76
A lot of users replied with modifying the program to make the PIC have lower consumption to last the 90 day countdown perioud, but I have not seen no one helping me out making the program buy Dave and Dave's program consumes to much power. Again im more inclined into hardware and can do just about anything with hardware and have great understanding with electronics circuits but have not clue whatsoever with programming. Any help here please on getting the program!
 

Dodgydave

Joined Jun 22, 2012
10,050
I have built the circuit you need with the pic, and it takes 760 micro Amps at 4.7V in idle mode, then takes 8mA when the buzzer beeps or led flashes,

so you have DEFINATELY wired it up wrong!


Edit if you use a 3V 1.8ah battery it will last 90 days in standby at that current of 760 micro amp,

if you want to use a CR2032 button battery of 240mAh, its going to need to provide 100micro amps for 90 days, so your circuit needs to take lower current...
 
Last edited:

Thread Starter

MLD

Joined Dec 7, 2012
76
I have built the circuit you need with the pic, and it takes 760 micro Amps at 4.7V in idle mode, then takes 8mA when the buzzer beeps or led flashes,

so you have DEFINATELY wired it up wrong!


Edit if you use a 3V 1.8ah battery it will last 90 days in standby at that current of 760 micro amp,

if you want to use a CR2032 button battery of 240mAh, its going to need to provide 100micro amps for 90 days, so your circuit needs to take lower current...

How can my circuit be wired wrong if all im using are 3 components. The PIC, the battery, and the buzzer. All wired direct to the PIC. Idle consumption without the buzzer hooked up to it consumes 56mA with the coin battery it will drain it just within a few hours. I've already did the test with two brand new PICs.
 

Papabravo

Joined Feb 24, 2006
16,834
Have you tied the unused inputs to a known voltage level? Unused inputs on a CMOS device can consume prodigious amounts of power. I'm surprised at the dearth of schematics in this thread.
 

Dodgydave

Joined Jun 22, 2012
10,050
If you connect the pic on its own to the 3V battery, pin 1 positive, pin 8 negative and measure the current, no buzzer or leds.
 

OBW0549

Joined Mar 2, 2015
3,566
How can my circuit be wired wrong if all im using are 3 components.
That's two components more than the minimum necessary to screw something up royally. Bottom line is, you are doing something wrong, somewhere.

Post a schematic diagram, please, so we can figure out what it is. Make it complete, accurate, and show ALL connections-- every last one. Until you do that, we're just going to be spinning our wheels here, because there's ABSOLUTELY NO WAY a PIC12F675 can draw 56 milliamps unless you've got something wired wrong.
 

JoeJester

Joined Apr 26, 2005
4,390
Post a schematic diagram, please, so we can figure out what it is. Make it complete, accurate, and show ALL connections-- every last one. Until you do that, we're just going to be spinning our wheels here,
With four months into this project, I'll say the wheels will spin a lot longer before you see anything resembling a schematic.
 

Dodgydave

Joined Jun 22, 2012
10,050
Here is how to connect the pic and buzzer/led, at switch on pin 7 is high and pin 6 is low, and change state after 3 months....



pic.png
 

JoeJester

Joined Apr 26, 2005
4,390
Dave,

I ment the TS providing a schematic to help troubleshoot the excessive power consumption.

Then again, it cold be an I'd 10T error.
 

Papabravo

Joined Feb 24, 2006
16,834
As always there are at least two possible approaches to the TS/OP's problem.
  1. He's right and we're all crazy in which case Microchip has a problem -- Houston!
  2. Our combined years of experience suggests he look a bit deeper.
At least those were the first two that came to mind.
 
Last edited:

Thread Starter

MLD

Joined Dec 7, 2012
76
Well at first I was told by DAVE to use pins 2 & 3 as the outputs, so I wired pin 3 to the positive of my buzzer and the negative of my buzzer i tied it to ground. The battery I tied the negative terminal to pin 8 of the PIC and the positive terminal of the battery i tied it to pin 1 of the PIC that is my circuit. Now Dave is telling my pins 7 and 8 are the outputs. So which is it DAVE !!

Now PAPABravo says to tie the unused pins to either high or low, I was not aware of this and have not tried this yet. DAVE which pins should be tied high and which to low so they will not be left floating like PAPABRAVO is suggesting?

Hopefully I can clear out this circuit soon with less current draw and run it using a coin battery.
 

AnalogKid

Joined Aug 1, 2013
9,362
A PIC was suggested in post #2. DD put his firmware in post #9. We're now at post #53 and still no schematic from you. Nothing else matters.

Your circuit is drawing over 50,000 time more current than it should. I don't care how careful you are about anything - that kind of discrepancy means there is a hardware error somewhere. This thread can go on for another few dozen posts, but without YOUR schematic and images of YOUR assembly, how can you possibly hope for any change?

ak
 
Last edited:

Alec_t

Joined Sep 17, 2013
12,215
Any unused pins tied to high or low should be programmed as inputs; otherwise the current is likely to increase dramatically :eek:.
 

Dodgydave

Joined Jun 22, 2012
10,050
Yes in the programme i made for you its pins 2, 3 that are the alternating pins., so use pins 1, 2, or. 3, 8

all other pins are configured as outputs and are low, so no connection to them.
 

Thread Starter

MLD

Joined Dec 7, 2012
76
Yes in the programme i made for you its pins 2, 3 that are the alternating pins., so use pins 1, 2, or. 3, 8

all other pins are configured as outputs and are low, so no connection to them.

So Dave the left over pins should be tied low to ground? I cannot leave them floating or can I?
 

Thread Starter

MLD

Joined Dec 7, 2012
76
Any unused pins tied to high or low should be programmed as inputs; otherwise the current is likely to increase dramatically :eek:.

Dave says the left over pins are outputs not inputs in his program. Is this incorrect?
 

Thread Starter

MLD

Joined Dec 7, 2012
76
A PIC was suggested in post #2. DD put his firmware in post #9. We're now at post #53 and still no schematic from you. Nothing else matters.

Your circuit is drawing over 50,000 time more current than it should. I don't care how careful you are about anything - that kind of discrepancy means there is a hardware error somewhere. This thread can go on for another few dozen posts, but without YOUR schematic and images of YOUR assembly, how can you possibly hope for any change?

ak

AK Ive already explained in details what pins are wired up. That is how I have it. Read post # 53
 

Dodgydave

Joined Jun 22, 2012
10,050
The unused pins should be left unconnected, as they are outputs, the only input is pin 4 mclr, which is not used.

Your pic sould be only taking about 760 micro amps, if its taking over 10 milli amp there is something wrong.
 
Top