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by JizzaDaMan
Sat Jan 04, 2014 11:41 pm
Forum: Beginners
Topic: Input pin voltage tolerances
Replies: 3
Views: 596

Input pin voltage tolerances

What is the minimum voltage that will register as 'logic 1' on a GPIO pin (set as an input), and conversely, what is the highest voltage that will measure as 'logic 0.'

What I'm hoping for is that around 2.8V will register as logic 1 and 0.1V will register as logic 0.

Thanks
by JizzaDaMan
Sat Jan 04, 2014 1:05 pm
Forum: Automation, sensing and robotics
Topic: Simple transistor question
Replies: 7
Views: 1367

Re: Simple transistor question

Thanks :) so I've got a 5k24 resistor and it seems to be lighting the LED brightly so I'm happy with that :)
by JizzaDaMan
Sat Jan 04, 2014 12:28 pm
Forum: Automation, sensing and robotics
Topic: Simple transistor question
Replies: 7
Views: 1367

Simple transistor question

Very simple question - I'm using a transistor to drive an LED. I have the LED wired in series with a 390 ohm resistor, and I've got a p.d. across the LED ~1.2V. Powered by a 6V battery pack. Meaning I've got a current of about 12mA (so let's say I work on 15mA), and I don't want this to be reduced b...
by JizzaDaMan
Wed Aug 21, 2013 8:21 pm
Forum: Other projects
Topic: Controlling many lights individually
Replies: 20
Views: 7492

Re: Controlling many lights individually

Hopefully tomorrow I'll be able to talk to the director. I think I'm going to try and convince him to use LEDs, because looking into it it will be cheaper and a billion times easier :P I looked into the addressable RGB LEDs, and that was getting potentially a bit expensive, although certainly the si...
by JizzaDaMan
Tue Aug 20, 2013 8:08 pm
Forum: Other projects
Topic: Controlling many lights individually
Replies: 20
Views: 7492

Re: Controlling many lights individually

A possibility. See here viewtopic.php?t=14524&p=157033 for issues of long cables and voltage isolation
Will I too need protection because of interference? Will opto couplers be sufficient if I do?
by JizzaDaMan
Tue Aug 20, 2013 2:03 pm
Forum: Other projects
Topic: Controlling many lights individually
Replies: 20
Views: 7492

Re: Controlling many lights individually

And considering the vast array, I would probably control each half with one pi each
by JizzaDaMan
Tue Aug 20, 2013 1:34 pm
Forum: Other projects
Topic: Controlling many lights individually
Replies: 20
Views: 7492

Re: Controlling many lights individually

Thanks for your advice Pigraham. I will talk to the director about the possibility of LEDs with ping pong balls on as it will significantly reduce power, cost, weight, wiring, everything! :D Let's say I have to use golf ball lights, does this plan sound reasonably feasible?: From the pi, I control 2...
by JizzaDaMan
Tue Aug 20, 2013 12:51 pm
Forum: Other projects
Topic: Controlling many lights individually
Replies: 20
Views: 7492

Re: Controlling many lights individually

richiepp: The director specifically asked for golf ball lamps, I don't think LEDs would have quite the same effect. They're basically just fairly small, rounded, incandescent light bulbs. redhak: I didn't think to use a triac, that's definitely a good idea. In fact I think I have a whole bunch of th...
by JizzaDaMan
Tue Aug 20, 2013 12:13 pm
Forum: Other projects
Topic: Controlling many lights individually
Replies: 20
Views: 7492

Re: Controlling many lights individually

By the way if any of you guys have any ideas that might work I'd be more than glad to see them :)
by JizzaDaMan
Tue Aug 20, 2013 11:58 am
Forum: Other projects
Topic: STICKY: The projects list. Look here for some ideas.
Replies: 232
Views: 380672

Re: The projects list. Look here for some ideas.

I'm planning to use my pi to control 200 golf ball lights individually using my pi for a production. (I'm a lighting technician for a theatre company). Still haven't quite worked out how I'll do it yet :P
by JizzaDaMan
Tue Aug 20, 2013 11:47 am
Forum: Other projects
Topic: Controlling many lights individually
Replies: 20
Views: 7492

Controlling many lights individually

I am the lighting technician for a school play this Christmas. My ambitious director told me he wants 200 individually controlled golf ball lights (Yes I know; Ambitious!). He wants various effects like 'explosions' of light from a single point, or a sort of wave of light travelling around the ring ...
by JizzaDaMan
Fri Jun 14, 2013 9:45 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Building circuit to protect GPIO
Replies: 12
Views: 14867

Re: Building circuit to protect GPIO

Thanks a lot for all your help :)
by JizzaDaMan
Fri Jun 14, 2013 6:58 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Building circuit to protect GPIO
Replies: 12
Views: 14867

Re: Building circuit to protect GPIO

I think I'll go for the zener diodes then. Just one thing I want to clear up; let's say, in the zener diode arrangement I set an output to high, which is at 3V3. The zener breaks down, and there is an unlimited current from the pin to ground. Is this not a problem?
by JizzaDaMan
Fri Jun 14, 2013 5:33 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Building circuit to protect GPIO
Replies: 12
Views: 14867

Re: Building circuit to protect GPIO

I am using the 74HCT245 as a buffer for inputs and outputs. Basically, if the chip would cut out before the Pi does, then that protection will be sufficient
by JizzaDaMan
Fri Jun 14, 2013 9:59 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Pin headers on the Pi
Replies: 1
Views: 572

Pin headers on the Pi

Can anyone tell me where I can buy the 26 pin headers like the one used on the Pi for GPIO?
by JizzaDaMan
Thu Jun 13, 2013 10:22 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Building circuit to protect GPIO
Replies: 12
Views: 14867

Re: Building circuit to protect GPIO

See here: http://elinux.org/RPi_Tutorial_EGHS:GPIO_Protection_Circuits Depending on my application I use either transistors, a ULN2803A, an opto, or a combination of these. I have actually read this post, which is where I found the chip I'm using, so I just wanted to confirm how much protection it ...
by JizzaDaMan
Thu Jun 13, 2013 10:13 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Building circuit to protect GPIO
Replies: 12
Views: 14867

Re: Building circuit to protect GPIO

What protection will my circuit offer?
by JizzaDaMan
Thu Jun 13, 2013 5:54 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Building circuit to protect GPIO
Replies: 12
Views: 14867

Building circuit to protect GPIO

I'm looking to build a circuit board to protect my Pi (I learnt the hard way that it's way too easy to blow things up :/ ) Anyway, my thoughts are to by two of these chips: http://www.nxp.com/documents/data_sheet/74HC_HCT245.pdf I would wire up each GPIO pin to an input on the chip via a 180R resist...
by JizzaDaMan
Thu Jun 13, 2013 5:35 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO breakout board labelling
Replies: 3
Views: 2228

Re: GPIO breakout board labelling

Thanks a lot for clearing that up :)
by JizzaDaMan
Thu Jun 13, 2013 5:23 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO breakout board labelling
Replies: 3
Views: 2228

GPIO breakout board labelling

I have this breakout board for my Raspberry Pi: http://www.maplin.co.uk/gpio-board-with-terminal-block-for-raspberry-pi-682474?c=maplin&utm_source=gcs&utm_medium=gcs_search&utm_campaign=N31NT&utm_content=Raspberry+Pi&%7Bifpe:_$ja=tsid:49900%7Ccgn%3A%7Badtype%7Dkw%3A%7CN31NT%7D%7Bifdyn:_$ja=tsid:4990...
by JizzaDaMan
Thu Jun 13, 2013 12:25 pm
Forum: General discussion
Topic: Wiring a shift register
Replies: 8
Views: 1985

Re: Wiring a shift register

Well that's a bit annoying :P I'm sure I'll find another use for them :D Just to confirm, if the chip had been able to sink 25mA, would my circuit work? Did I daisy chain them correctly? And what do I connect the resets to?
by JizzaDaMan
Thu Jun 13, 2013 11:48 am
Forum: General discussion
Topic: Wiring a shift register
Replies: 8
Views: 1985

Wiring a shift register

I am using two dual 4-bit SIPO shift registers (CD4015BE, Datasheet - http://pdf1.alldatasheet.com/datasheet-pdf/view/159328/TI/CD4015BE.html ) to drive 2 LED 7 segment displays. The reason is so I can use just a few pins by daisy chaining them together to drive the displays rather than the 16-or-so...
by JizzaDaMan
Thu Apr 18, 2013 6:23 pm
Forum: Beginners
Topic: Cennecting to Pi with ConnectBot
Replies: 7
Views: 7084

Re: Cennecting to Pi with ConnectBot

fantastic! I have complete control from the terminal on my phone now :)
by JizzaDaMan
Thu Apr 18, 2013 5:28 pm
Forum: Beginners
Topic: Cennecting to Pi with ConnectBot
Replies: 7
Views: 7084

Re: Cennecting to Pi with ConnectBot

I have downloaded fing to my phone, and I think I have the IP address, so now how do I connect to it, since ConnectBot asks for: username@hostname:port
by JizzaDaMan
Thu Apr 18, 2013 5:01 pm
Forum: Beginners
Topic: Cennecting to Pi with ConnectBot
Replies: 7
Views: 7084

Re: Cennecting to Pi with ConnectBot

Where can I find out the IP of the pi?

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