Raspberry Pi Forums

ame wrote:Picture a player-piano with a paper roll with holes in it to play a tune.

No, no, no. We want interaction. Picture a MIDI keyboard that plays the umbrellas in a live performance. Or they respond to the sound of music, like an FFT spectrum analyzer. Or perhaps use a Leap Motion device to read hand gestures. Or...heck you probably have your own ideas. The point being that it's easy now to programmatically control the servos with say, Python, in response to just about any input you can think of, it doesn't have to be predetermined. And by 'easy', I mean many frustrating hours of code debugging.

Douglas6 wrote:

ame wrote:Picture a player-piano with a paper roll with holes in it to play a tune.

No, no, no. We want interaction. Picture a MIDI keyboard that plays the umbrellas in a live performance. Or they respond to the sound of music, like an FFT spectrum analyzer. Or perhaps use a Leap Motion device to read hand gestures. Or...heck you probably have your own ideas. The point being that it's easy now to programmatically control the servos with say, Python, in response to just about any input you can think of, it doesn't have to be predetermined. And by 'easy', I mean many frustrating hours of code debugging.

I was thinking baby steps first.

ame wrote:I was thinking baby steps first.

Yes, good point, I got carried away.

dadcanyouhelp wrote:Hi All, never heard of Raspberry Pi until about an hour ago, an assistant in Maplin told me a bit,
My daughter is in her last year at uni and is onto her final pieces, so I got one of those "can you help Dad" calls

Katie wants to Automate approx 10-20 cocktail umbrellas just to open and close in a sequence or to be pir/pressure activated,
my initial thought was to use small servo's to operate the umbrellas and have some form of transmitter/receiver set-up but then Katie said about Arduino's so i went off to maplins and hey presto i'm now trying to learn quickly about RP and hopefully get some advice and guidance from forum members PLEASE ??

Cheers
Tim

Could I suggest a CMOS Decade Counter
To con troll your project ,By buffering the
Out/puts to give you the power you require

You might only need one GPIO out/put
That you can program as a clock pulse
Timing at the speed you want.

If you want more out/puts you can
Cascade more Decade Counters

Amazing help so far guys! Before I fully ingest Ame's suggestions with writing some commands, we're building our first prototype with a single brolly, but we've hit a snag again...

As soon as the servo is connected up to the external power source (5v) the servo moves without us sending any commands. It moves but can still be turned by hand. When we send the echo command, it doesn't react. It was working fine yesterday; any ideas?

Yours,

Katie and Tim.

Edit: Changed pin and it worked? Will upload a photo of it soon so you can see

My favourite way to use servos.

https://www.youtube.com/watch?v=HBFMTbcNLtg

Tarcas wrote:

dadcanyouhelp wrote:Hi All, never heard of Raspberry Pi until about an hour ago, an assistant in Maplin told me a bit,
My daughter is in her last year at uni and is onto her final pieces, so I got one of those "can you help Dad" calls

Katie wants to Automate approx 10-20 cocktail umbrellas just to open and close in a sequence or to be pir/pressure activated,
my initial thought was to use small servo's to operate the umbrellas and have some form of transmitter/receiver set-up but then Katie said about Arduino's so i went off to maplins and hey presto i'm now trying to learn quickly about RP and hopefully get some advice and guidance from forum members PLEASE ??

Cheers
Tim

well... with the right hardware and code, the Pi could do it. So could an Arduino. What are you thinking for hardware? Servos can work with the Pi, but there are probably other options that could work too.

Do remember that the Pi's GPIO pins are 3.3v with a max of 16 mA per pin with a max total of 50 mA.

It seems a good project . Opening and closing
Cocktail Umbrellas
Not being a party goer , I have never seen a
Cocktail umbrella. What are the mechanics
Of how the umbrella opens and closes
How are you linking it to the server.
Would small Solenoids do the same job

Agreed, I've been watching this thread with curiosity and don't understand how the umbrellas open. Perhaps I'm not a cocktails guy

Initially I thought perhaps one motor could be used with cams or levers to open all of them in one sequence, but if the sequence can change they'll definitely need one "actuator" of some sort each.

Ravenous wrote:Agreed, I've been watching this thread with curiosity and don't understand how the umbrellas open. Perhaps I'm not a cocktails guy

Initially I thought perhaps one motor could be used with cams or levers to open all of them in one sequence, but if the sequence can change they'll definitely need one "actuator" of some sort each.

I think at one point, servos and pneumatics were each mentioned. IMO, I think pneumatics would probably be the better choice, but I'm not sure if that's still on the table since servos are all that have been discussed at length.

When I hear cocktail umbrellas I think of something like this but I'm hoping he's planning on using something a little bigger, heavier, and much more durable if he expects any machine to open it repeatedly.

Dad: Can you send a link to whatever hardware you were thinking of using, so we can see what it might be compatible with?

Can you imagine a hundred of them in a 10x10 matrix being made to "flap" scrolling messages?

EDIT - or simulate a Pacman game?

Perhaps something like this?

How about this - forty syringes (in different sizes):
http://www.rapidonline.com/Education/Te ... wwodnpYAGA
Trouble is you would need some sort of pressure source to supply them. One could be rigged by "pumping" one of the bigger syringes with a motor, but that would need a non-return valve and probably other stuff I think.

Also it wouldn't drive them in a programmable sequence. All at once or perhaps in a fixed "wave" but for fully programmable control you would need 20 motors to go with the 20 large and 20 small syringes. The syringes would be quite compact but it'd be pretty complicated and a heckofa lot of piping...

boyoh wrote:

Tarcas wrote:

dadcanyouhelp wrote:Hi All, never heard of Raspberry Pi until about an hour ago, an assistant in Maplin told me a bit,
My daughter is in her last year at uni and is onto her final pieces, so I got one of those "can you help Dad" calls

Katie wants to Automate approx 10-20 cocktail umbrellas just to open and close in a sequence or to be pir/pressure activated,
my initial thought was to use small servo's to operate the umbrellas and have some form of transmitter/receiver set-up but then Katie said about Arduino's so i went off to maplins and hey presto i'm now trying to learn quickly about RP and hopefully get some advice and guidance from forum members PLEASE ??

Cheers
Tim

well... with the right hardware and code, the Pi could do it. So could an Arduino. What are you thinking for hardware? Servos can work with the Pi, but there are probably other options that could work too.

Do remember that the Pi's GPIO pins are 3.3v with a max of 16 mA per pin with a max total of 50 mA.

It seems a good project . Opening and closing
Cocktail Umbrellas
Not being a party goer , I have never seen a
Cocktail umbrella. What are the mechanics
Of how the umbrella opens and closes
How are you linking it to the server.
Would small Solenoids do the same job

This is one Idea, Might work