Robot Efficiency & other Robot stuff

[williB]

they are unipolar.. six wire steppers with 2.3 ohms resistance..and i am using 5V to drive them.. the measured current is 1.4A... dosent add up..does it..hmm

 

[Nigel Goodwin]

they are unipolar.. six wire steppers with 2.3 ohms resistance..and i am using 5V to drive them.. the measured current is 1.4A... dosent add up..does it..hmm

That's because it's not a resistor :lol:

 

[bloody-orc]

hey again!
but wenn you take off the wheel and then drive it and hold it with fingers will youre stepper stopp? well i mean of course that you dont grab it wery strongly but enaugh hard(cant say the exact amount of force :wink:

 

[williB]

hey again!
but wenn you take off the wheel and then drive it and hold it with fingers will youre stepper stopp? well i mean of course that you dont grab it wery strongly but enaugh hard(cant say the exact amount of force :wink:

mine have a fair amount of torque.. when i run them if i grab the wheel tightly.. the rim will keep spining..
you have no torque on your steppers ?

 

[williB]

hey what steppers did you use and how much current\voltage do they take?
i´m thinking of mooving my own robot with steppers but when i put my stepper running on the table without any wheels or anything then it seems that the stepper is to weak i have a 5V\0.5A stepper and controller is uln2003a and pic

i am driving them with the exact configuration as Nigel has on his site except i am using IRF 510's instead of the ones he is using..

 

[bloody-orc]

hey again!
ok mine are to weak. where did you get those? Did you bought them? All i have tried are all from copymashines\printers\etc. and it seems they are all toooo weak. :cry:

 

[williB]

yes they are from a copier/printer also

 

[bloody-orc]

could you say all the information about them? all what is written on them...(if this is not mutch trouble)

 

[williB]

well i've had a pretty good morning..
I found not one , but two 12V 2.3Ah batteries at a garage sale, they came with a Bell Atlantic Special Edition Cell Phone..Very early model..
$3.00!!!
Can U say Robot Power...lol

 

[williB]

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

 

[williB]

: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*

 

[Nigel Goodwin]

: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*

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?.

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*

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.

 

[williB]

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.

i did'nt know about it..

 

[williB]

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?.

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..

 

[williB]

https://www.electro-tech-online.com/custompdfs/2004/11/39589b.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"???

 

[williB]

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 .

 

[Nigel Goodwin]

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!.

 

[williB]

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..

 

[williB]

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

 

[williB]

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..