PIC Open source Servo Driver Schematics development?

[slp_prlzys]

Hi,
first of all I know little
of electronics and programming,
but highly motivated

I'm trying to recreate microchip an696a
appnote using CCS C and PIC18f452.
It took me a while to figure out data types
between compilers are not the same.
I've got some of the things setup, PWM
is working fine, using 40Mhz crystal @ slightly
over 20Khz PWM, Timer2 setup to 4 division
and period of 120.(I'm using it as locked antiphased
as it was called) So my PWM range is arround 0-239 negative
direction 241-480 for positive direction.

My problem lies in trajectory generation,
being a newbie, I'm confused. I'm not doing it
exactly as it was done in the appnote, I can't
understand (yet) the shifting and rotating they did
on that. (As I understand, it was done because
there was no 32bit support on the earlier compilers).
I want to make it simpler so as to understand
what is going on and since CCS support int32.

Now, what I need is a sample code in C
(I was gonna say preferrably in C but that's
all I know for now) for trajectory generation
or motion profile, I'm confused between
velocity profile and position profile are they
both used at the same time? My googling
hits, mention something to calculate time
during acceleration to maximum acceleration to
decceleration, to get a trapezoidal profile. I'm
not quite sure how to implement that. So any
help would be greatly appreciated. BTW the
PID I'm using comes from here:
http://www.lewisw.worldonline.co.uk/cservo.htm
It's basically the same thing as in appnote(I think)
but no use of union that confused me with shift and rotate thingy.

Basically I'm going to use this to give new life to
a dead epson1270 that I found and convert it to
cut vinyl stickers(if successful), it has 2 servos
one with rotary the other with linear encoders.
not sure of the count yet, it seems so many.
the pic18f452 is already setup for 2 PWM output,
with one encoder input is using external interrupt,
the other is using timers as in appnote an696a.
Actually I set it up like Timer0 and External Interrupt for
encoder one, Timer1 and External Interrupt1 for
encoder two. The counting seems to be working.

Thanks.

[smarbaga]

tachus42
can u convert your schematic files to orcad or pdf or bmp please as i don't use eagle
thank you

[smarbaga]

spl
the trapeziod must be able to fit into your total movement distance or it will be a ramp up ramp down with no plateau (which is ok )
the rise ramp and de-ramp or at least the falling ramp must be subtracted from the total # of turns.
also tool up down should be considered.
i tried to figure this all out, at one time .
i think i tried to fly before i could crawl.
i have notice most plotters move slow then take off
i think they are calculating the ramps.
maybe just divide the target location by 2 and ramp till u get there, with a ramp max limit and or test a bit for max acceleration reached and de-acceleration start.
well u know it is a visious circle, just thinking about it makes my head spin.
best of luck

[gabrielus]

do you have any documentacion about this hardware?
and what is the software can i use with this hardware?

[dirk c]

Hi to everybody,
I picked up a controller on a auction a wile ago, with a lot of searching i found someone that has a cnc router that uses the same boards. Now what ai want to do is make the other 2 boards i short for making my own machine. I have verry little electronics experiance, but have built a stepper controler and have driven it with kcam. I am wondering if annybody out ther would be willing to help me draw the 2 boards i need. i live in south africa finding help here is not easy.

[smarbaga]

show me the schematic ro a pic of what u want.

[danadams]

I have a half finished design I'm willing to contribute. Has been tested and works but needs more testing, a few rough edges smoothed over and documentation.

Features: Avr microcontroller - much more power than a pic (1 controler can cope with 3 axises) and only a few dollars more.
LCD and Key pad to enter PID values and jog without controller connected.
Seperate driver board with 3 18200 hbridge driver chips giving 3 amps at 36 volts.

Attached are Eagle PCB files for the Controller and motor driver boards. If there is any interest I'll rustle up the source code to go with them.

Hi

Yes, I woud be interested in the source code for attemt at further develpment of your driver. Thanks

[Luslugger]

http://www4.ncsu.edu/~dsbloomf/Steve...vo%20Drive.htm This link is not working.

[venomx999]

I have these DC servo motors with encoders. Will let someone have it for $100 even, free s/h within the US.

Made by Shinano Kenshi, Japan. Rated at 30Volts, 1.8amps.



They are really nice motors, brand new.

[zoltan]

It is $100 each? Are you shipping to Romania? How I can pay you? Do you accept card or wire transfer? I have other way mean.

Thank you.

Zoltan

[spotlite]

It is $100 each? Are you shipping to Romania? How I can pay you? Do you accept card or wire transfer? I have other way mean.

Thank you.

Zoltan

Hi,
I think I have easy solution for you.
I live in Bulgaria. I constructed
a CNC plasma cutting machine, using Bulgarian Servo Motors with encoders.

Motor: 56V , 12A , 3000 rpm
Encoder: 2000 pulses/ rotation

These are extremely stable devices, produced under FANUC-FUNJITSU license
years ago in Bulgaria.

I think I can find some at the price:

Motors - 50 EUR
Encoders - 150 EUR

:-)

[pongthep]

Thank for all,
which share information.
Regards
Pongthep

[agelkom]

I made a single side PCB for Linistepper driver (Roman Black's) and add:
Over current circuit,
multiturn current trimpots for different type of motors,
Opto coupler for protecting pc's i/o,

[James Newton]

I made a single side PCB for Linistepper driver (Roman Black's) and add:
Over current circuit,
multiturn current trimpots for different type of motors,
Opto coupler for protecting pc's i/o,

Are you willing to share that design? Either here or at the Linistepper homepage for user modifications:
http://www.piclist.com/techref/io/st...istep/mods.htm

[agelkom]

Of course, I will post it in a few days
Argun Gucdemir

[agelkom]

Linistepper (Lini8) board and schematic files attached.
Please note that power transitor mounted bottom of pcb due to thermal runaway on large heathsink.

[agelkom]

Hi,
Here is the PCB copper and layout pdf files for Linitepper Lini8. I can post if gerber files required.
Argun

[tady]

tachus42 coud you please post the XEH files of your desing?
i'm not good in compiling codes

[RRR]

Hi Argun,
It's very interesting design. Coud you post the component list?
Romas

[agelkom]

Hi Romas
The component list and schematic files for my Lini8 are attached.
A few important notes:
1. Darlinton Power transistor has protection diode however it is not as fast as schotky so that I add diodes.
2. R11A and R12A for optional
3. I also add D12 C7 J4 and R11 for current control when the "step" pulses are exist.
4. Power transistor mounted buttom of PCB
5. S1-2 Step , S1-3 Dir S1-4 Current control inputs S1-5 Over currunt output,
S1-1 input GND
Regards
Argun