Newbie looking for advice on servos and timers

Projects General Guidance
1

Hello,

I suppose I will start in the project guidance section so as to get advice and then expand from there to specific forums. I am a newbie to Arduino. I finally (after months of thinking about it) got an Arduino Uno and Starter kit. I am enjoying it very much but an eager to expand on some things. So for my first project I would like to build a system that can do these specific tasks.

  1. Keep track of time.
  2. Operate a continuous servo that can pull for example a max of 10kg.
  3. Have setting for both the clock and servo that tell the system WHEN to move (i.e. rotate servo) and HOW MUCH to move.

I want to make a system where I specify a time interval between rotations so i can lower an object attached to a wire, at specified amounts (e.g. lower 10cm then stop for 10min then lower 10cm etc).

Now I know I'm just a newbie, but I have experience in languages such as MATLAB but haven't taken C++ for 10 years. So I'm working on getting back into that language. I've been looking at the libraries available for doing such things as keeping time or motor controlling but I'm beginning to think it would be best to combine a actual clock 'chip' (if that's what i'd call it).

So I have some questions if anyone might be able to enlighten me a bit briefly.

  1. Once all is said and done I can transfer the code from the UNO to say for example a NANO? To make the package smaller?
  2. The servo in the kit is tiny. I've looked around online and seen continuous servos that say they can pull multiple kgs, and since I need control of how much it turns ( i.e. know the angle rotated, size of spool, then arc length into wire lowering length) I figured a servo is the best option (without getting into rotary encoders). Is it possible to pull this much mass with a servo?
  3. Are chip clocks better than the 'code' clocks? So far I'm not impressed with all the code needed to sync the time from the computer. As well I'd like to to keep time independently from the computer when disconnected.
  4. Am I right in thinking all this needs is the Arduino, clock chip and servo? Or would one of the motor control boards help?

If anyone might be able to confirm or provide some other advice about this project I'd greatly appreciate it. So far I've been able to complete many of the projects in the kit and alter them to have a bit of fun. I'm thoroughly impressed with it and would like to try and move to a bit more advanced projects.

Thanks for any advice or help you can give and apologies if this is not the right place to start out this discussion.

Cheers!

2

JRMertes:
Hello,

I suppose I will start in the project guidance section so as to get advice and then expand from there to specific forums. I am a newbie to Arduino. I finally (after months of thinking about it) got an Arduino Uno and Starter kit. I am enjoying it very much but an eager to expand on some things. So for my first project I would like to build a system that can do these specific tasks.

  1. Keep track of time.

Google 'arduino RTC'

  1. Operate a continuous servo that can pull for example a max of 10kg.

I think that a stepper motor would be more capable of lifting that much weight.

3

With a continuous rotation servo, you can NOT control how far it turns. All you can control is the speed. You would need to experiment to determine how long to run the motor at a given speed to achieve the motion that you desire.

4

You're going to need a pretty substantial servo to cope reliably with loads that high. Given that you'd be butchering it to use for continuous rotation, you would have to provide some other mechanism for sensing the position/travel since it would no longer provide direct position control. That being the case, it might be better to get a small DC motor/gearbox combo with a rotary encoder attached to the output. It would solve the problem just as well for a fraction of the cost. For example I have an small motor with an integral 300:1 epicyclic reduction that produces extremely high torque from 12V at about 100 mA; that's low enough to be controlled by a small, cheap integral H-bridge which removes the extra cost and size of external motor drive shields etc.