8055 and Servos

I already have a k8055 Board that i have played with..

I plan to make my simulator out of wiper motors.. and I want to do as little MCU programming as possibly (as ive never done this before)

I am just going to buy pre-built boards...

My train of thought will be to plug a pre-built board (such as the 8055) to a Parallax's HB-25 motor controller, that connects to the motors..

HOwever the k8055 can NOT control servos can it? what do people connect the 8055 to and how?
Would i jsut be better off buying a SSC32 so it hooks striaght up?

Ehmmm... One small detail... the HB-25 are not true SERVO controllers!!!! They are actually bidirectional SPEED controllers with RC-servo pulse input! :lol:

You still need a microcontroller to implement the PID closed input position control with an external feedback. That's what I have done on my first motion controller prototype (Basic Stamp2 based) that you can see below on the link of my signature... or here:
http://ptyxiouxos.net/greekbotics/user_projects/Flight_Simulator/Electronics.htm

:

Regards, Thanos

I know its not a true servo.. but my theory is if i can control a Servo then I can control a motor with HB-25 as they are the same inputs.

Can I not use the 8055 as the external feedback?

If i can get away with out learning how to program a microcontroller ill be a happy man.

I don't think you can implement external position feedback using the 8055... Its just a dump interface!

Here are some problems you have to solve:

One is that the 8055 is just an I/O interface that doesn't run its own code, hence you need to program a computer inteface to control it.

Second is that the update rate between the 8055 and the computer is more than 50ms. In between that time your motor will be already on its physical end stop before the computer read back the feedback of the potentiometer and stop it. For such PID position control you need almost realtime calculation that can be implemented only inside the control module (microcontroller ).

Even a beginners microcontroller like the Parallax Basic Stamp2 can do better these things than 8055!


Regards, Thanos

I think i'll just make your circuit and upload your program to basic stamp chip...

So if i re-create your exact boards.:
Custom BS2 board and all connections in one place interface:

The only MCU that i ahve to pgroam is the basic stamp chip.. And then that circuit connects directly to the HB-25 whch connects to the wiper motors?

Im sure i'll be able to make minor adjustments to the basic stamp program if needs be..

Well, I don't really recommend to use this old interface. Its too slow, and outdated.

You could just build the new AMC1.5 interface, and the custom DSMhb1.2b motor controller:

tronic-s-amc-motor-motion-controller-with-pwm-servo-output-t559.html
tronic-s-diy-dual-mosfet-h-bridge-dsmhb-t820.html

The AMC1.5 contains an on-board programmer to load the free firmware I made on it. And the DSMhb1.2b is designed to drive wiper motors and even a larger 24V motors under certain conditions.


Best Regards, Thanos

im trying to re-create exactly same circuits as you...

im just having problems with the max232 chip.. is this chip the same ?:

MAX232 Dual RS-232 Receiver Transeiver IC

also in your items list you said (Notice that these two max232 chips are the same, just different firm).
i dont notice any pictures of hte max? do i need 2 of them?

im just slowly getting the items list sorted.

Yes its the same. (MAX232 Dual RS-232 Receiver Transeiver IC)
Just be sure to purchase the DIP size and not an SMT type...

The AMC1.5 board needs only one MAX232.


BTW. Is your computer equipped with serial ports? If not, look for FTDI based USB-to-Serial adapters (Digitus for example).

Regards, Thanos