heelppp!!!!! 16f628 problem

[be80be]

Here a simple one

 

[blueroomelectronics]

I don't use Proteus or breadboards (unreliable), I'd prefer to hand wire prototypes as I'm from the age of wire-wrapping. I do use the debugger and MPLAB simulator.

 

[be80be]

Burt,
On your circuit
Check the bias current path from the +B thru the PNP forward biased diode and the clamp diodes in the PIC.???

eric I posted a short didn't I I did that totally backwards It wasn't even no ware near right.


See if this is not better

 

[zhaniko93]

Hey I inserted resistance instead motor and everything worked fine! I think it's really EMF but flyback diode didn't help I inserted it as shown on figure..... why didn't it work? unfortunatelly I don't have oscilloscope to explore it

 

[ericgibbs]

Hey I inserted resistance instead motor and everything worked fine! I think it's really EMF but flyback diode didn't help I inserted it as shown on figure..... why didn't it work? unfortunatelly I don't have oscilloscope to explore it

hi z93,
The diode is drawn the wrong way around.

 

[zhaniko93]

Oh yes I drew incorrecly, but in my project I inserted correctly, I'm lazy to upload it again so imagine that it's rotated by 180

 

[ericgibbs]

Where are your decoupling and filter caps? You need em on a real circuit.

Hi,
I would ask this same question as Bill, show the full circuit diagram, including the power line decoupling.

 

[zhaniko93]

here I uploaded them

 

[be80be]

Metal–oxide–semiconductor field-effect transistor are voltage controlled. zhaniko93 is using one that's not able to turn on at 5 volts right. His 9 volts motor supply make's it a if'e it may work some time and may not. In Mulisims 11 it will not turn on with 5 volts at the gate.

 

[ericgibbs]

Hi,
The decoupling you show on that diagram is far too little for reliable operation when driving loads.
Use at least a 47uF or 100uF and two or three 100nF, one located near the PIC

 

[zhaniko93]

be80be
Gate Threshold Voltage MAX is 4V and why isn't 5v enough?

ericgibbs
I'll buy them. will electrolyte capacitors be appripriate?

 

[ericgibbs]

be80be
Gate Threshold Voltage MAX is 4V and why isn't 5v enough?

ericgibbs
I'll buy them. will electrolyte capacitors be appripriate?

The 47/100uF will electrolytic and the 100nF general purpose decoupling caps.


http://www.interfacebus.com/Design_Capacitors.html