Not related directly to robots, but has to do with robotics i guess

Community General Discussions
1

hi guys,

i've been following this website a lot, but im relatively new to this forum. im not into robots but im simply facinated by the functions so achieve.

as the title suggest i have a query to solve, which i am sure that someone here can help me out on. 

basically i need to setup an IR receiver and transmitter to control a DC motor. apart from this i need to set up the DC motor to be programmed to stop after completing X amount of revolutions. ie having limits to where to stop. with the possibilty also to make it stop at any point at command.

is there any volunteer to help out. thanks in advance..

 

warren

2

Motor travel

How important is the exact motor travel? If it is very important, maybe you could substitute a stepper instead of a standard dc motor as a stepper can be programmed to run a specific number of steps, which would be easier and probably more precise than having an encoder on a dc motor for position control.

OT, the rest of your request would be easy to implement w/ a uC, some programming and a modulated IR receiver.

I must also mention that my knowledge is only book smarts. I have never built a single useful thing, to date.

3

Well a picaxe with the Ir

Well a picaxe with the Ir remote kit and the L293D (or more powerful one for bigger motors) would allow you to control the motor easily.

As for counting the revolutions I’m guessing an optical detector like this http://www.sparkfun.com/products/246 would do the job. Not sure if the picaxe could keep up your motor is spinning very fast. I haven’t set up a rev counter yet so I can’t help you with the code. 

Hope this gave you some idea. 

4

Well a picaxe with the Ir

Woops double post 

5

hey there, first of all

hey there, 

first of all thank for your prompt help,

i did not mention the use in my first post, cos you would have laughed at me. I find it very hard in the morning or late at night to go out of bed just to open the blinds. so i have to figure out a way to do it mechanically. from bed. 

iknow that i can just go and buy one, but id prefer to build the thing myself as a project. I an architect and have little knowledge oof things but with some help i think we can get there… :slight_smile:

i was thinking of getting a high torque 12V dc motor, hook it the rotating knob of the and pull the blinds up. the blind i have are roman blinds, the ones without the rotating things. just cloth tht folds upwarsds…

i ws thinking of getting one of these:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220725573524&ssPageName=STRK:MEWAX:IT#ht_4660wt_1026

i need the ‘limits’ of travel, since someone else might use it and would keep on going till the end snapping the mechanism. if i was using it myself only i wouldnt have bothered doing such thing as i would stop a bit below the end point. 

i would like it to start, keep going till the end with the ability to stop it at any point.

as regards the other parts, i really have little knowledge of where and what to get. I will be more than happy to picture everthing and posting them here.

what i will need for sure from what im seeing: board for programming motor , dc motor, stopper sensor (or rev counter), IR controller, power supply for both…

guys if this is somthing that is not related in anyway to this website, just let me know… 

6

I think you could build this

I think you could build this with your current motor and;

  • Two limit switches (upper and lower position)
  • H-bridge motor controller
  • A small microcontroller like PICAXE to handle the IR remote and control the direction of motor rotation.

I’m using the same type of motor in my project https://www.robotshop.com/letsmakerobots/node/22108 but I think your 4 RPM would take the curtains forever to reach its position (if you’re not using one massive spool) so do some calculations on that before you order.

And yes, your project is well suited for the ‘something else’ section

7

so, motor ordered. i got

so, motor ordered. i got another one with higher revs.

do you thing that i can start with somthing like this? http://www.sparkfun.com/products/8321 , how do i power the 12V motor if this is 5V?

remote : http://www.sparkfun.com/products/10280

sensor: http://www.sparkfun.com/products/8753

still i do not know which is the most efficient way for the 'limits’

as you may (certainly) notice. im far beyond novice on these things…  

8

I like Mr. Andersen’s idea

I like Mr. Andersen’s idea as well. It sounds "simple."

With the PICAXE08M you can decode IR signals (it’s a built in feature) with a IR receiver as described in the second PICAXE user manual.

You can run a voltage regulator to make a 5V source off of your 12V power supply. I recommend OddBot’s excellent write-up about dealing with power supplies here.

The limiting switches will give your microprocessor signals that the blinds have been fully raised or lowered. Something simple like a snap switch at the top of the blinds that will trigger when the blinds are pulled up is all you need. Maybe a switch on the windowsill that gets triggered when the blinds fall on them would take care of the other end of the business.

9

As you are fairly new to the

As you are fairly new to the world of electronics and programming I would recommend that you started out with a protoboard and did some initial tests first.
I have this board http://www.techsupplies.co.uk/epages/Store.sf/en_GB/?ObjectPath=/Shops/Store.TechSupplies/Products/AXE091U and its great for testing out ideas. It has some switchs, LEDs, potentiometer etc already mounted so you just have to run some jumper wires to them.
I also would recommend that you went for a bigger chip then the 08M, -maybe a 18pin. There is a great little project board that already has the H-bridge (L293D) socket installed. I think that board would be perfect for your project http://www.sparkfun.com/products/8330 take a look at the datasheet http://www.rev-ed.co.uk/docs/CHI030.pdf