Breadboard and my microcontroller.

[Gayan Soyza]

Off Topic!

When I design sign boards I first choose correct high efficiency LED's or LED Matrixes.So I can drive them with a low duty cycles later to minimize the power consumption without notifying any brightness changing situations.

 

[Nigel Goodwin]

danielsmusic,
You need at least 0.33uF on the input and 0.1uF on the output of the 7805 or it may become unstable. Put them as close as possible to the 7805. You should also have a 0.1uF close to the PICs power pins.

Yes, this is why we asked for the COMPLETE circuit, and it shows a complete lack of required capacitors - you need a capacitor on the input pin of the 7805 as well, and a good size electrolytic across the battery.

 

[danielsmusic]

I did initially have a capacitor either side of the regulator. I noticed that it seems to slow down the clock speed on the PIC so I removed them.

EDIT: Only tried >1uF cap on output, I will try the recommended 0.1uf when I get home. And some across the battery.

 

[petrv]

you should never leave out the capacitors. I always put 0.1uF ceramic to both input and output of 78XX and also electrolytic capacitors (both on input and output). Also it is highly recommended to put 0.1uF ceramic capacitors to each digital IC (as close to its power pins as possible). Otherwise you can experience some "unexplainable" problems especially at higher speeds and with logic ICs that are fast (high slew rate) and switching bigger currents ....

 

[danielsmusic]

Adding any sort of capacitor anywhere in the circuit completely stops the PIC and it does nothing.

 

[petrv]

If adding a capacitor between +5V and 0V (power supply) stops it from working then I guess your circuit must have much more serious problem than it seems.

 

[danielsmusic]

If adding a capacitor between +5V and 0V (power supply) stops it from working then I guess your circuit must have much more serious problem than it seems.

With a very large capacitor across the battery terminals it will stay flashing a bit longer than without any capacitors at all. Although having the same capacitor across 5v and 0v it won't work at all.

 

[3v0]

What voltage is the battery?
What voltage does the volt meter show for the battery?

You really should post the schematic for this thing starting with the battery. It could save a lot of time and posts.

A picture that was good enough to follow the wiring would be good too.

 

[danielsmusic]

What voltage is the battery?

12V

What voltage does the volt meter show for the battery?

13V

You really should post the schematic for this thing starting with the battery. It could save a lot of time and posts.

I posted a picture a bit further up.


EDIT: Here's something interesting, if I hold an output pin on the PIC high with a small load (LED), it works with a 0.1uF capacitor across the battery, but as I add more across the IC etc it will slow down the PIC although the pattern is still there.

 

[blueroomelectronics]

Take a photo of your device, with the caps. Why are you using a shift register why not just drive the LEDs directly from the PIC?
PS the 74HC595 can only source a couple of mA (it can sink more than it can source) Your LEDs need about 470ohms if you wish to drive them from the 74HC595.

 

[AtomSoft]

what if you change the power source(battery) try using another source. Also check for floating pins. I think i used to get similar issues when a pin is left floating and i didnt disable the interrupts.

 

[danielsmusic]

I'm hoping that when this is sorted out, I will be driving a lot of LEDs.

 

[AtomSoft]

what kind of wires are those? Exposed?

 

[danielsmusic]

The smaller ones are, yes.
No luck with floating pins, I set all the I/O pins to output.

 

[kchriste]

As per your breadboard picture:
Make a little room by moving the PIC downwards one set of holes. Then put the crystal and caps right next to the OSC pins of the PIC. Don't use long wires like that for the crystal as it will cause these types of problems.
Get some insulated buss wire, cut it to various lengths and strip 1/4" off the ends. Use that instead of bare buss wire which is prone to shorting out.
You should also get rid of all those "croc clips". Those are notorious for intermittent contacts.

 

[theo92]

Why these non coated wires on the breadboard?
A small touch can create a lot of problems.
I think it all should be small hook-up.
They're very cheap, looks cute, breadboard socjet easily accept it and easy to use.

 

[danielsmusic]

I'll try some enamel copper wire when I get home and move the crystal directly to the PIC. I'll post the results a bit later on.

 

[mike50]

The 7805 regulator you are using appears to be in a TO-220 case. That device, with no heatsink (as in your breadboard) has a maximum power dissipation of about 2 watts. With 12 volts input it must drop 7 volts across the regulator. You are drawing at least 250 ma. This requires the 7805 to dissipate 1.75 watts. I would expect the 7805 to get too hot to touch. If you are actually drawing 300 ma, the 7805 will be over the maximum and may shut down.

You might put a 10 ohm, 10 watt resistor between the battery and the regulator input. This will allow much of the voltage drop to be across the resistor instead of the regulator and it will run much cooler.

Mike

 

[ericgibbs]

I'll try some enamel copper wire when I get home and move the crystal directly to the PIC. I'll post the results a bit later on.

hi,
Get some old multi core telephone wire,from the local scrap yard, its ideal for project boards.

 

[AtomSoft]

I Use ethernet cables since i can get them for $2 each 6ft long with 4 pair wire so thats the equivalent of 48 feet. Not alot but comes in hand when im broke

The trick i do is to solder the wire to pin headers and make single and double even quad wires. Its nice and plugs in GREAT!.

Resistance on wire is not much if nothing. About 0.1 ohms. I think less tho. Lets just say my reader reads .2 with nothing and .2-.3 with the wire so it has to be practically nothing