@Rich : how much accurate/precise is the measurement in this case ?

It depends on the sensor. The ones I use are 4cm to 30cm range and are extremely accurate, 26cm range accurate to around 1mm. It depends on the length of the shaft I guess, you could put one on top and one on the bottom, if one is out of range measure from the other to get the distance, so in effect 2 sensors can position something in a 60cm (2 foot) range.

There are other sensors which measure further too, but obviously the further you go the more each ACD value is equal to. If it was a 52cm range it would be around 2mm per ADC. Basically range/255 = distance per ADC value.

Hi guys,

Thanks so much for your ideas and interest in my problem. I'm afraid I don't have a clue about the items you are suggesting. I'm very mechanically minded, so I'm sure I can figure it out, but I'm totally new to electronics. Would it be possible for me to upload some photos and measurements so you can see the dollhouse and have one of you give me a list of parts I would need to purchase and some instructions as to how to put the whole thing together?

BTW, someone mentioned a rope or string stretching after time with a load in the elevator. I was hoping to use a chain or something stronger than a rope or string...

Thanks,

Anne

That was me mentioning stretching I guess with a chain it wouldn't be an issue.

Do you know the length of the lift shaft? If you let me know that then I can give you the correct part number for the Infra Red Sensor and you can decide if you want to use that idea.

Something like the Sharp GP2Y0A02YK0F will basically plug in to an ADC port on the EZ-B, it then reports a voltage to the EZ-B, this voltage can be converted to distance, or if you stop the lift in position and read the value you know what to set it to stop at.

You then use scripts to move the lift, with some GetADC commands and loops etc. (I'll explain more if you go down this route) and the lift moves to the required position. It's very simple really.

Yes, it is better to have the description .

• The shaft length and design.
• Expected weight to hold.
• Functionality needed for the elevator and anything else for the dollhouse

Rich : I read that ping sensors readings are affected with the cable connection length . Is this applicable to IR ones also ?

Not that I am aware but I also wasn't aware that some IR sensors distance/voltage is a curve not linear...

However, if the sensor is in place and the wiring is fixed the simplest way would be to install the lift, move it to position, record the value on the sensor and use that for reference.

i.e. move the lift to the ground floor, read the ADC, that value is ground floor, let's say a value of 27. move the lift to the first floor, read the ADC, that value is the firs floor, let's say a value of 58. and so on until all positions are known.

Then, the script to move to position checks the ADC, if moving to ground floor it moves until ADC=27 then it stops. If moving to first it moves until ADC=58 and stops. You get the idea.

Hi guys,

I called servo City today and talked with a tech. He said that all I need is a HS-785HB servo that turns 3.5 rotations and a Pololu controller with presets. He said that I would need to set a minimum and maximum pwm signal and then set points in-between for the stops at the various floors. He said that servo City carries the Servo, but that I would need to contact Pololu for the controller. So, I called Pololu and talked with a tech there as well. She said that she thought the best controller for my application was the twelve-channel Micro Maestro controller. She said that I would need to read the user guide for the controller to see if it is what I need. I told her I have no way of knowing, since I have never done anything like this before!

She didn't mention a power source, but I know I will need a power supply, and she suggested that I get some push button switches and a breadboard, since there is no remote control available.

So, are any of you familiar with these items? Are these what you were describing?

Anne

This is what I have built so far of the dollhouse. It is 43" tall and there is approx 7" between the floors.