if you typed something...i am not seeing it

 

in the last no this is blank(was a duplicate) but could you say all the information about them(steppers)? all what is written on them...(if this is not mutch trouble)

 

what kind are your steppers..?

 

these are Minebea
type 23KM-K379-G1
at the bottom it says
NO T8Y03

 

:cry: Bad news..
i was programming and debugging my only 16F84A and something happened ..
it stopped running.. i was blinking LED's and trying to get the steppers to run on the pic.. the steppers didn't seem to have the power that they had when i was using the PC to drive them..
all of a sudden it just stopped blinking the LED's...tried to reprogram it but all it reads is ones...*sigh*
I did get two other pics when i ordered the 16F84A, but one is the 18F2220 a compleatly different animal , and a 16F874 .
But i am a little hesitant to use the new 40 pin 874 for fear that whatever happened to his little brother would befall him..lol
*sigh*

 

PIC's really take some killing, so you must have done something rather drastic to it! - I presume you were feeding it from 5V?, and have the required capacitors on the regulator IC?.

Ordering the obselete 16F84 seems a really strange thing to do?, why didn't you order it's modern replacement the 16F628, cheaper chip and a higher spec as well.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

i did'nt know about it..

 

yes.. well they were on the other side of this cable..
ya see , i was using the 5v supply from the pc.. and the pc was fine,..it was still running..so .. i just dont know..

Attached Images

untitled_0006_0001_604.jpg (19.6 KB, 931 views)

 

http://ww1.microchip.com/downloads/e...Doc/39589b.pdf
on the top of page 13..left side
is that backwards?
it says if they are set " reads as 0 "
or left unchanged "reads as 1"???

 

Ok i am back in business..Got my new 628's from microchip yesterday ( in less than a week)..!!
tried programming one .. worked like a charm..so now i have to figure out what happened to the F84A.
Nigel recommended caps close to Vdd & Vss any recomendations on what values.?
I am thinking of supplying the 628 with its own 5v regulator .

 

I would suggesting looking at my tutorial boards, they work very reliably, and I would certainly suggest you have a 5V regulator on the board!.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

this is my current diagram.
the Eagle software didnt have a 16F628 but did have a 16F84A ..
I think that i turned the wheel by hand causing an induced voltage to ruin the last PIC.. hopefully it wont happen again..
Battery 2 is going to be NiMH 1.2 V batteries giving 4.8 Volts hope this is enough to turn the gates on..if not maybe a combination of batteries of different types will work..

Attached Images

stepper2.gif (13.5 KB, 879 views)

 

so what does anyone think ??
will this prevent the motors from frying the new chip.??

 

this design is much better..
i scoped the LM317 output , not a blip to be found..
i think this one is a LOT safer for the PIC..

Attached Images

stepper3.jpg (46.8 KB, 858 views)

 

Your schematic shows an external diode in parallel with each PMOS.

This should not be necessary. All PMOS that you get off-the-shelf have an internal body diode inside in this direction already. You can read your spec sheet but usually they are capable of carrying substantial current.

Your schematic lacks a capacitor on the output of the reg. This could cause the reg to oscillate and potentially blow your chip.

You need to put a ceramic cap from Vdd to Vss right at the PIC chip, especially on a power circuit like this. I already had this trouble more than once- nearby power consumers, even though they didn't even draw power out of the reg, were causing the PIC to latch up.