Gina's Observatory Roll-Off-Roof Automation - Work in Progress

[Gina]

I have most of the mechanical parts of this project done but it still needs the electronics finished - hence work in progress.

It will be using a more or less standard garage door opener motor.  This uses standard bicycle chain (single speed type) to pull the roll-off-roof open or closed.  The less standard part of the opener is that it has a clutch so that the mechanism can be disengaged and the roof operated manually in cased of some sort of failure.  I didn't want to have the roof open with rain starting and a motor or other failure.  I couldn't find any roof openers with a clutch in the UK but a friend in Sweden obtained one for me.

This is the underside of the motor showing the chain run and dog clutch.

The chain runs in the top groove and is held onto the sprocket by the red bit.  Other parts are to do with limit switches but I'm using separate limit switches operated by the roof, more of which later.

[Gina]

Next the arrangement of chain and pulleys.

The chain, motor and pulleys are attached to the south side of the roof which has lower running track and more moving wall, on the inside.  Here are a couple of diagrams showing the chain run, motor, and pulleys.

To get enough length 4 or 5 bicycle chains were joined together using joining links.  The smaller pulley was 3D printed but the larger one was turn on a lathe from a n acetyl blank.

[Gina]

Chain attachment to roof for pulling it open.

Motor, smaller pulley and chain attachment via spring to roof for pulling it closed.

 

[Gina]

I'm using these limit switches to detect roof closed or roof open.

[Gina]

Limit switches in position.

[Gina]

I have a couple more photos to take when the rain stops but for now a taste of things to come.

Block diagram of the electronics.

[Gina]

I have yet to decide what I am going to do about the fold-down east window.  At one stage I had it coupled to the roof so that opening and closing the roof opened and closed the window but I have since realised that there are times when I want the window open with the roof closed, so I think I shall want independent remote operation of the window.  A hinged window is rather different from a roll-off-roof in operation so this will need thinking about.

[MarkAR]

Excellent work Gina, seems like quite a complex job getting everything to work.

[silentrunning]

Looks great Gina. Wish I was fit enough to attempt something like that - then again maybe it's a good thing I can't!

[Carastro]

Just full of admiration.

Carole 

[Gina]

Thank you everyone - much appreciated.  Getting everything working properly is certainly no easy job and threads like this tend to make it look easy.  I have only posted what may be the final job after many blind alleys and changes.

[Jkulin]

Posted by: @Gina

Thank you everyone - much appreciated.  Getting everything working properly is certainly no easy job and threads like this tend to make it look easy.  I have only posted what may be the final job after many blind alleys and changes.

Gina, somehow, I don't think there will ever be a final job for you as your mind is so active and creative, you will always think of some way to improve it.

I only wish my mind was half as good as yours!

 

[Gina]

Posted by: @Jkulin

Posted by: @Gina

Thank you everyone - much appreciated.  Getting everything working properly is certainly no easy job and threads like this tend to make it look easy.  I have only posted what may be the final job after many blind alleys and changes.

Gina, somehow, I don't think there will ever be a final job for you as your mind is so active and creative, you will always think of some way to improve it.

I only wish my mind was half as good as yours!

 

Thank you very much John ?   I'm sure your mind is a lot better than you say!!

 

[Gina]

I'm thinking about remote control of the fold-down window.

This is the current arrangement.

Open

Closed

This is a Heath_Robinson string operated arrangement where the window was opened and closed by the roof.  This works but I really want independent operation.

Cord drive in practice.
https://stargazerslounge.com/uploads/monthly_2019_07/1917467705_WindowCordPulleySystem01.JPG.2f7cb1e2c93304bb546636eaf2f77a5e.JPG

 

https://stargazerslounge.com/uploads/monthly_2019_07/523432803_WindowCordPulleySystem02.JPG.42118d8b384c10c9f4301fced422abd0.JPG

I use shock cord to pull it open ATM

https://stargazerslounge.com/uploads/monthly_2019_08/1370373115_WindowBungeeCord01.JPG.497aed235c4874ee75162fe134345e6b.JPG

[Gina]

Because this happened and it jammed.
https://stargazerslounge.com/uploads/monthly_2019_07/1419814000_WindowCordPulleySystem03.JPG.693accd2e6f5e7341a8725c68d7dbd1a.JPG

I made my own 3D printed block which cured the problem by made it less easy to uncouple.  I guess I could add a hook and get over that problem.
https://stargazerslounge.com/uploads/monthly_2019_08/876442697_WindowCordPulleySystem04.JPG.f83dc6c78526d9f050df01c8423b009f.JPG

But there's still the silly shock cord method of pulling the window open which I don't really like.

[Gina]

I'll have a think as to whether I want full independent remote control of the window, with all the complication that involves in the design, or whether I only want the window open when I'm in the observatory or it's no problem to pop back and forth from the house.

[Gina]

Decided to just use the string system with an S hook on the pulley block so that I can uncouple it if I want the window open with the roof closed.  (Easier than undoing the screw in the photo above).

[Gina]

This is a photo of the manual (local) control box.  This is used for local control of the roof within the observatory and will be on the dividing wall in the warm room.  Green button closes the roof, white button opens it and red button is an emergency STOP button for use in case of trouble.  The LEDs are coloured and show green - closed, blue - closing, yellow - opening and white - open.  These states are displayed on the Dashboard computer display indoors and controls on the Dashboard replicate the three buttons.  In addition the motor current is displayed indoors for confirmation that things are alright.  When local control is used the current is displayed on the digital ammeter in the power distribution box.

The motor that drives the roof is controlled by a Pololu Dual VNH5019 Motor Driver Shield as I was originally thinking of using an Arduino and this would have saved a lot of connections.  https://www.pololu.com/docs/0J49

Only one of the two motor drivers on the board are expected to be used but the second is available if wanted such as if I decide to operate the window independently.

These drivers have a "H" format meaning that they can drive the motor in either direction by reversing the polarity.  I'll explain this later in the technical details.

[Gina]

As this is work in progress I will be posting each stage as I work towards the final result.

This shows the pin connections of the ESP32.  I just need to decide which I am going to use.

 I need 2 outputs to drive the motor control board and inputs for the limit switches (2), the control panel buttons (3) and the motor current which is an analog voltage derived from the current and the rain sensor.  That means one ADC input, 5 digital inputs and 2 digital outputs.

[silentrunning]

This is awesome Gina.

You have given me some ideas for opening and shutting the potting shed I use as an observatory. I don't need a powered automatic solution just something that means I don't have to take the full weight of the slanting panel of the shed when I remove it at the beginning of a session. I need to hinge it somehow so that is stays in at the bottom. Your window arrangement has given me some ideas. :-) 

[Gina]

Thank you.  Glad I have given you some ideas.  That's what this is about.  ? 

[Gina]

Simplest to use the pins down the left hand side of ESP32 (in image above) for the GPIO connections. I'll draw a layout diagram shortly.  The ESP uses the same code as an Arduino and the Arduino IDE for programming so I can use the code I developed for an Arduino with changes for the GPIO connections and a few other things.

Here's the Arduino sketch (code).  Let's see if this works - been experimenting with this forum software.

http://ginad.uk/RORautomation/ArduinoSketch.txt

[Gina]

Detailed wiring diagram.

[Jkulin]

An inspiration to many Gina, ? 

Have you thought about chain operating the front panel rather than cords, less room for error or snagging and probably easier to configure?

[Gina]

Posted by: @Jkulin

An inspiration to many Gina, ? 

Have you thought about chain operating the front panel rather than cords, less room for error or snagging and probably easier to configure?

Thank you John ? 

Yes, I have considered chain but cord is easier and actually works pretty well.  That you for the suggestion.