Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: youandih on November 24, 2012, 05:38:22 AM
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I'm not familiar with building robotic stuff at all, but Im trying to start somehow.
As some sort of first 'experiment', I want to try and make my curtains (roller blinds), be controlled through a program on my computer.
My idea was to connect an electric motor to the rope which pulls it up. It simply needs to run at a constant speed controlled by USB (or bluetooth, but I suppose that's far to complicated). If anyone can get me started with controlling an electric motor by USB, that'd be awesome.
Greetings, Youandi Hoefman
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Here is an inexpensive motor / gearbox that would give you several speed / torque ranges to experiment with.
http://www.pololu.com/catalog/product/70 (http://www.pololu.com/catalog/product/70)
Pulleys and other drive attachments are available at http://www.servocity.com/html/smooth_hub_pulleys.html (http://www.servocity.com/html/smooth_hub_pulleys.html)
Can you explain why you want your computer to control the blinds?
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Sure it's cause I recently moved to Amsterdam, and I got one entire room for my computer and electronic stuff. My PC is now running Dragon NaturallySpeaking, and i'm trying to make it respond and sound similar to JARVIS from Iron Man. Now since JARVIS controls an entire house instead of just a computer, I'm trying to make it control my room by computer, by Dragon, and thus by voice. I already figured something out for the lights to be on and off at my command, but obviously my fantasy didn't agree with just that. So the next step would be controlling my blinds by voice.
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Hi,
I'm not familiar with building robotic stuff at all,
How about soldering then?
My idea was to connect an electric motor to the rope which pulls it up. It simply needs to run at a constant speed
Get a small gearhead motor for that - without the gearing, it won't have the muscle for it. How fast do you want it to run?
If anyone can get me started with controlling an electric motor by USB, that'd be awesome.
Just get something like this:
USB Relay Controller with 6-Channel I/O (https://www.sparkfun.com/products/9669)
You'll need to have some sort of detection on when the blinds are fully opened and closed (unless you want to only control it manually while looking at them).
You'll need two relays (ore one relay and one I/O plus an external transistor driver) to control each blind (unless you control all motors in parallel).
The relay board has a temperature sensor as well.
How's your programming skills?
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1) No, unfortunately I'm not familiar with soldering either.
2) The best speed I think is for the curtain to move up at 3 or 4 inches per second, so considering the gear sizes 1 rotation per second for the wheel connected to the string should do it.
3) If you mean software programming, I'm not that skilled, but my father is, so he can help me with that, that shouldn't be a problem.
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Hi,
1) No, unfortunately I'm not familiar with soldering either.
Bummer!
I don't see it happening without soldering, but it's not that hard to learn.
2) The best speed I think is for the curtain to move up at 3 or 4 inches per second, so considering the gear sizes 1 rotation per second for the wheel connected to the string should do it.
You need a gearhead with an output speed of around 60 RMP then.
How much torque is needed?
You can meassure either with a luggage- or fishing scale, or by placing a container on the string that has to be pulled and add weight until it pulls it without hesitation - then weigh the container with whatever you added.
If this container weigh eg. 1.7 kg and the radius of the pulley will be say 1.2 cm, you need at least 1.7/1.2 kgf-cm of torque.
3) If you mean software programming, I'm not that skilled, but my father is, so he can help me with that, that shouldn't be a problem.
Good then.
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A little change of plans: im not going to connect the motor to the string but directly to the curtain axis itself (where the rope usually goes to)
The weight needed to pull it up is 2,2 kg, and the radius of the pulley where the rope is connected to is 2 cm.
(attachment is a quick paint illustration which should make thiings clearer)
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Hi,
A little change of plans: im not going to connect the motor to the string but directly to the curtain axis itself (where the rope usually goes to)
The weight needed to pull it up is 2,2 kg, and the radius of the pulley where the rope is connected to is 2 cm.
You'll need a minimum of 4.4kgf-cm (61.1 ozf-in) then and something like this motor (http://www.robotshop.com/ca/solarbotics-gm17-gear-motor.html) fits the bill.
This particular motor will give you a speed of around 6.75 cm per second max. (@6V/29mA) and if you want it slower, either use PWM or lower the voltage a bit.
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So I need the USB Relay Controller with 6-Channel I/O and the GM17 228:1 Gear Motor.
Are there any other things I need to have or know?
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Hi,
So I need the USB Relay Controller with 6-Channel I/O and the GM17 228:1 Gear Motor.
You need either those, or some with the same functionality.
Are there any other things I need to have or know?
You need a 6V power source for the motor (the relays doesn't supply power).
Wire to connect the motor to the relay board - regular mains wire can be used, just don't connect to the mains!
Screwdriver, side cutters and whatever else tools you need to attach the motor as you want.
If you need help, when you have gotten the relay board, motor and 6V power source, just post the relay switch details :)
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An alternative to a relay board would be a USB motor controller. It will have built-in capability to run the motor both forwards and backwards, rather than using two different relays. Something like this perhaps:
http://www.pololu.com/catalog/product/1372 (http://www.pololu.com/catalog/product/1372) (18V, 7A, assembled)
This comes with screw terminals and pin headers, so you may not need to solder much at all.
The USB connection will let you tell it to run forward or reverse, at various speeds, as desired.
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Hi,
An alternative to a relay board would be a USB motor controller. It will have built-in capability to run the motor both forwards and backwards, rather than using two different relays. Something like this perhaps:
http://www.pololu.com/catalog/product/1372 (http://www.pololu.com/catalog/product/1372) (18V, 7A, assembled)
This comes with screw terminals and pin headers, so you may not need to solder much at all.
The USB connection will let you tell it to run forward or reverse, at various speeds, as desired.
If the purpose is to automate the process, it won't work, as there's no way to feedback end limit info and if the purpose is using visual feedback with manual control, there's no need for a PC, as that could be done with a simple switch.
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Hi,
An alternative to a relay board would be a USB motor controller. It will have built-in capability to run the motor both forwards and backwards, rather than using two different relays. Something like this perhaps:
http://www.pololu.com/catalog/product/1372 (http://www.pololu.com/catalog/product/1372) (18V, 7A, assembled)
This comes with screw terminals and pin headers, so you may not need to solder much at all.
The USB connection will let you tell it to run forward or reverse, at various speeds, as desired.
If the purpose is to automate the process, it won't work, as there's no way to feedback end limit info and if the purpose is using visual feedback with manual control, there's no need for a PC, as that could be done with a simple switch.
Looks like limit switches to me!
http://www.pololu.com/picture/view/0J2910 (http://www.pololu.com/picture/view/0J2910)
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Hi,
An alternative to a relay board would be a USB motor controller. It will have built-in capability to run the motor both forwards and backwards, rather than using two different relays. Something like this perhaps:
http://www.pololu.com/catalog/product/1372 (http://www.pololu.com/catalog/product/1372) (18V, 7A, assembled)
This comes with screw terminals and pin headers, so you may not need to solder much at all.
The USB connection will let you tell it to run forward or reverse, at various speeds, as desired.
If the purpose is to automate the process, it won't work, as there's no way to feedback end limit info and if the purpose is using visual feedback with manual control, there's no need for a PC, as that could be done with a simple switch.
Looks like limit switches to me!
http://www.pololu.com/picture/view/0J2910 (http://www.pololu.com/picture/view/0J2910)
I know that you're just dying to find flaws in what I write, but apparently you didn't put your heart into it, or you would have gotten the full story (and stayed your hand as a consequence). So, once again, I ask you to not confuse the OPs with superficially researched nick nack.
And further, to not give the OP a false impression, here's what the so called "kill switch" settings are for (which isn't external end limit switches):
• Forward limit switch: When the scaled value of the channel is above 1600 (50%), the limit switch will be considered active and the motor will not be allowed to move forward. If the target speed is positive, a “Limit/kill switch” error will occur.
• Reverse limit switch: When the scaled value of the channel is above 1600 (50%), the limit switch will be considered active and the motor will not be allowed to move in reverse. If the target speed is negative, a “Limit/kill switch” error will occur.
Since you obviously have spare time for trouble shooting of my posts, I assume you have found (at least some of) the flaws of the mic amp you posted a while back and are ready to comment?
If not, just say the word and I'll enlighten you.