![]() |
![]() |
![]() |
|
|
|||||||
| Robotics Chat Specific to discussions about robots and the making of. |
|
|
Thread Tools | Display Modes |
|
|
(permalink) |
|
hu has circuit for stepper motor to rotate from 0-180 deg. back n forth continous...plz....using registers ttl ic's.
|
|
|
|
|
|
|
(permalink) |
|
To drive a stepping from 0 to 180 deg, you need a program, not a circuit.
If you need a stepping driver, you may try with some driver chip: ULN 2003 or 2803 for 2 motors. It's the simplest way to drive a stepping. If you wanna use a H bridge, try with L298 and L297 (L297 is the higher level control chip, and enable you to drive a stepping with PWM).
__________________
Falleaf mail@falleaf.net English forums at PIC Vietnam - Vietnamese Electronics forums R&P Trading and Forwarding Co. Ltd. Distributor of Microchip in Vietnam |
|
|
|
|
|
|
(permalink) |
|
you need an up down counter
__________________
*Keep the parallel port on PCs.* |
|
|
|
|
|
|
(permalink) |
|
Your circuit will need the 3 stages.
:arrow: The POWER stage: This is a chip like a H-Bridge that connects to your stepper motor and has the ability to handle the voltage and current requirements for the stepper. Ex: L298 :arrow: The DRIVER stage: This is a chip that will be in charge of driving the POWER chip. The DRIVER chip will need to generate the right secuence to stepping the motor. It will drive the motor by accepting "CLOCK" inputs and converting them to steps. Ex: L297 :arrow: The COUNTER stage: This will be the clock for your DRIVER chip, it will generate the necesary clock pulses to tell the DRIVER to go 180 degrees and back. Ex: "4017 + 555 (monostable)" It would not be fun for you to show you the circuit, but you can start with the above information. :wink: Some thing to think about.... :?: how many steps are needed for a 180 rotation.? :?: How many pulses needed to achive the steps? :?: How can we use the "direction" pin on the driver chip.? Good Luck Ivancho |
|
|
|
|
|
|
(permalink) |
|
[PDF] www.st.com/stonline/books/pdf/docs/1773.pdf
Try this link, the datasheet of L298. I think you can easily connect L298 to MC, and it easy enough to write a simple program for stepping. You don't have to use L297 if you don't want to simplize your program even it's simple enough as with L298. However, you need to take care of short circuit protection, apply to both L298 and L293 (B/D)... goodluck.
__________________
Falleaf mail@falleaf.net English forums at PIC Vietnam - Vietnamese Electronics forums R&P Trading and Forwarding Co. Ltd. Distributor of Microchip in Vietnam |
|
|
|
|
|
|
(permalink) |
|
post your final sheme and a bit of software..
TkS tanxs.. |
|
|
|
|
|
|
(permalink) |
|
The datasheet of L298 and L297 show clearly how to connect to a stepper. I did as in the datasheet. But I added a short circuit protection to it. And the short circuit protection is also supported on www.st.com. I don't remember the direct link.
But it's as: a zener 4148 is connected from the inputs of L298 to signal pins of MC, and a capacitor is also connected in parallel with it. It's about 100pF. And a Resistor 10K should be connected from the inputs of L298 to the outputs of L298. You do it with all inputs and outputs.
__________________
Falleaf mail@falleaf.net English forums at PIC Vietnam - Vietnamese Electronics forums R&P Trading and Forwarding Co. Ltd. Distributor of Microchip in Vietnam |
|
|
|
|
|
|
(permalink) |
|
has a capp and a zener diode..??
how much pins does the mc needs to be free..??/ TKS |
|
|
|
|
|
|
(permalink) |
|
Well, the circuit should like this:
...........x-----||---x ...........|.............| |O|-----x---|<|----x---- |X| this is the input of L298 Don't care bout the .... , I have to add .... because if I don't, it cannot view exactly. ---- is the wire, and x is connected. |X| is the input pin of L298 and |O| is the output of your MC. You need only 1 pin, but in stead of connect it directly, you connect like this. And from the input of L298 to output of L298, you add a 10K resistor. If you got a email, I'll send you the test circuit, I used to test L298 with its all characters, such as: short circuit, feedback voltage via sense pins, 4A driver, ... and especially, we should note that if we use the normal diode for the H brigde, we cannot drive the motor upto 5KHz period of PWM, but if we use fast diode, it works good. And PWM is usually used at that frequency.
__________________
Falleaf mail@falleaf.net English forums at PIC Vietnam - Vietnamese Electronics forums R&P Trading and Forwarding Co. Ltd. Distributor of Microchip in Vietnam |
|
|
|
|
|
|
(permalink) |
|
offcourse
walter@wdrautomatisering.nl a orcad fiel would be fine or something in paint.. TKS (or Walter) |
|
|
|
|
|
|
(permalink) |
|
the fullview.pdf has been sent.
__________________
Falleaf mail@falleaf.net English forums at PIC Vietnam - Vietnamese Electronics forums R&P Trading and Forwarding Co. Ltd. Distributor of Microchip in Vietnam |
|
|
|
|
|
|
(permalink) |
|
parts list:
555 (create astable freq.) 74194 - for shift right shift left 7476 - FF. q and not q connected to s1,s0 of 194 unl2003 - stepper motor driver zener diode 12v 2pcs 74193 (make a binary of 100dec then nand to cp of FF.... stepper motor which has 1.8deg per step..... |
|
|
|
|
|
|
(permalink) | |
|
Quote:
Have in mind that it would have been easier to use a L293 + L298 combo (or similar chips) with a microcontroller, for practical purposes. But for learning purposes on how things work, your way is the best 8) Ivancho |
||
|
|
|
|
|
(permalink) |
|
Well, I don't know what you intend to do, but why do you need 555 and shift registers? ULN2003 is enough. What will your control signal come from? PC or MC? or you use 555 to get a fixed velocity?
__________________
Falleaf mail@falleaf.net English forums at PIC Vietnam - Vietnamese Electronics forums R&P Trading and Forwarding Co. Ltd. Distributor of Microchip in Vietnam |
|
|
|
|
|
|
(permalink) | |
|
Quote:
A microcontroller could actually generate those siganls needed but it takes too much time of the controller to generate them.... instead a specific chip can be used to generate that sequence for you, like the case of the L297, so that you only need one line to control the stepper instead of 4. Not to mention that software part will be reduced as well. By using those chips he mention somehow he comes with the right secuence without the need of programming, and that is an art. Ivancho |
||
|
|
|