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by Duane Degn
Tue Aug 19, 2014 3:56 am
Forum: Graphics, sound and multimedia
Topic: Analog Cam Recorder Project
Replies: 22
Views: 8045

Re: Analog Cam Recorder Project

But this Parallax Propeller is amazing too! Both Bill and myself are fans of the Parallax Propeller. Bill makes a cool board to make using the Propeller with the Raspberry Pi easier. He has a thread about the board here . Shipping the board to Brazil might cost prohibitive for you but you could sti...
by Duane Degn
Mon Aug 18, 2014 9:33 pm
Forum: Graphics, sound and multimedia
Topic: Analog Cam Recorder Project
Replies: 22
Views: 8045

Re: Analog Cam Recorder Project

I could have just said there is no way to do it on the Pi, but where is the fun in that? If you really want to, you could actually do a "slow scan" low resolution NTSC capture, but it would not be anywhere near full NTSC resolution, nor would it be 60fps. Do you have a guess if the Pi would be able...
by Duane Degn
Mon Aug 18, 2014 9:29 pm
Forum: Graphics, sound and multimedia
Topic: Analog Cam Recorder Project
Replies: 22
Views: 8045

Re: Analog Cam Recorder Project

Hey Duane! What a cool project! Thanks Renato. To be honest, I was surprised it worked as well as it did. It was one of my early attempts at writing code in assembly and I was really pleased I was able to PWM the LEDs using a stack of 74HC595 shift registers with 8-bit resolution without causing th...
by Duane Degn
Mon Aug 18, 2014 6:13 pm
Forum: Graphics, sound and multimedia
Topic: Analog Cam Recorder Project
Replies: 22
Views: 8045

Re: Analog Cam Recorder Project

You could capture monochrome video with a fast ADC chip. The ADC08100 is an 8-bit parallel ADC chip which could be used to capture a NTSC video. I used this chip with a Propeller chip to capture low res video to display to a DIY LED array. It was a relatively expensive, very low resolution way of ca...
by Duane Degn
Mon Aug 18, 2014 4:16 am
Forum: HATs and other add-ons
Topic: Ultra Bright LEDs
Replies: 13
Views: 2069

Re: Ultra Bright LEDs

You answered a couple of Grodon77's questions but you have not said anything about how much current the LED needs. This is important information when considering what sort of device to suggest.
by Duane Degn
Fri Aug 15, 2014 4:34 pm
Forum: Automation, sensing and robotics
Topic: Where do you start to create logic like a Roomba
Replies: 8
Views: 2237

Re: Where do you start to create logic like a Roomba

The Roomba , as far I know, doesn't use a mapping system. It does figure out the dimension of the room This is my understanding as well. The Roomba is very hacker friendly with a serial port where instructions can be sent and sensors read. With a pair of microcontrollers and cheap nRF24L01+ modules...
by Duane Degn
Sun Aug 10, 2014 3:45 pm
Forum: Beginners
Topic: Advice and help with dimmable UltraBright RGB LED
Replies: 4
Views: 783

Re: Advice and help with dimmable UltraBright RGB LED

In order to use a pot with a Raspberry Pi, you will probably want some sort of analog to digital converter (ADC), alternately you could use an encoder as an input device which could be read directly by the RPi. This encoder could be fun. You could have the Pi control the LEDs on the encoder to indic...
by Duane Degn
Sun Aug 10, 2014 1:51 pm
Forum: Other projects
Topic: Small high capacity battery
Replies: 3
Views: 1088

Re: Small high capacity battery

Hi. I am currently working on a raspberry pi laptop and need a good battery power supply. The problem is that I can't seem to find a high enough capacity battery to power both the Pi and the screen that is small enough to fit in the enclosure (I have exactly 4 x 10 cm to work with). How deep is thi...
by Duane Degn
Sun Aug 10, 2014 2:47 am
Forum: Automation, sensing and robotics
Topic: Rpi Camera With 4 Way Motor Controller: Advice Please!
Replies: 1
Views: 724

Re: Rpi Camera With 4 Way Motor Controller: Advice Please!

I don't know enough about the RPi camera to help with question #1 but I think I can answer this one. 2. I have seen 2 way motor controllers for the RPi but not anything that can control 4 independent motors, does such a piece of hardware exist? Yes, the hardware exists, two dual h-bridges. With an i...
by Duane Degn
Sat Aug 09, 2014 8:31 pm
Forum: Beginners
Topic: Advice and help with dimmable UltraBright RGB LED
Replies: 4
Views: 783

Re: Advice and help with dimmable UltraBright RGB LED

Is there a particular reason you want to use a Raspberry Pi to do this and not a microcontroller? If you want to learn to use the Raspberry Pi, then great use the Pi, but if you're learning to use the Pi just so you can control the RGB LED then IMO, you're making your project more difficult than it ...
by Duane Degn
Wed Aug 06, 2014 11:14 pm
Forum: Automation, sensing and robotics
Topic: Encoder help with Raspberry Pi
Replies: 7
Views: 1403

Re: Encoder help with Raspberry Pi

Yes, the spool has regularly spaced supports. I like the idea of the Mini Microswitch - SPDT (Roller Lever). As you recommended this, I thought of a location that a device like this could be placed to measure pipe footage. http://www.nov.com/hydrarig/images/HydraRigLandingPage_09.jpg See picture th...
by Duane Degn
Wed Aug 06, 2014 8:01 pm
Forum: Automation, sensing and robotics
Topic: Encoder help with Raspberry Pi
Replies: 7
Views: 1403

Re: Encoder help with Raspberry Pi

Thanks for the response. That gives me an idea of how I need to go about things. If the reel has regularly spaced supports, you could use some sort of switch as an encoder pulse. I was thinking of something like this switch but scaled to an appropriate size. A physical switch would have the advanta...
by Duane Degn
Wed Aug 06, 2014 6:33 pm
Forum: Automation, sensing and robotics
Topic: Encoder help with Raspberry Pi
Replies: 7
Views: 1403

Re: Encoder help with Raspberry Pi

In order to keep track of direction with an encoder, you want to use a quadrature encoder. Just about any microcontroller could read a quadrature encoder and there are lots of ways one could make these encoders. I'm sure the Raspberry Pi wouldn't have a problem reading a quadrature encoder. I haven'...
by Duane Degn
Wed Jul 30, 2014 7:52 pm
Forum: Automation, sensing and robotics
Topic: Need more than two 5v GPIO outputs
Replies: 5
Views: 3820

Re: Need more than two 5v GPIO outputs

I also want to connect another distance measurement module which also will require 5v but I have used both 5v outputs on the GPIO - how do I deal with that? Is it possible to split one of the 5v outputs or should i get another power supply just for that? This is a big "it depends". How much current...
by Duane Degn
Wed Jul 30, 2014 5:44 pm
Forum: Beginners
Topic: DC motor control help
Replies: 15
Views: 2656

Re: DC motor control help

There may be times when case 1 or 2 is better than the other. I expect those cases are outside most hobbyist usage . I'm hesitant to disagree with Joan, but I would say the following is more true. Edit: I see I was disagreeing about the wrong thing. I do think the difference is significant enough f...
by Duane Degn
Tue Jul 29, 2014 10:57 pm
Forum: Automation, sensing and robotics
Topic: Boardcomputer for a Motorcycle
Replies: 7
Views: 2344

Re: Boardcomputer for a Motorcycle

I got someone who can do these platines... Is "plantines" a person? Is this a typo? I don't understand what the above quote means. Is there a reason why you want to use the Raspberry Pi? What you've described so far sounds like a better fit for a good microcontroller. As rgrbic mentioned, you'll pr...
by Duane Degn
Tue Jul 29, 2014 4:46 pm
Forum: General discussion
Topic: LED help please
Replies: 91
Views: 10188

Re: LED help please

Do your plants need blue light? I have a few of these LEDs and they're really bright. One problem with the larger LEDs (30W) is they need to be driven at higher DC voltages than are easily available. I don't think your computer power supply will be able to power more than the 10W LEDs. But 10W LEDs ...
by Duane Degn
Tue Jul 29, 2014 7:30 am
Forum: Beginners
Topic: DC motor control help
Replies: 15
Views: 2656

Re: DC motor control help

They have an operating voltage of 1.5 ~3 volt, so do I need to power the L239D motor controller's VS with an external power supply of 1.5 ~ 3 volt or can I just my batteryholder consisting of 4 AA batteries? My battery holder gives off 6 volt (5.2V when the batteries are recharged.) The L293D needs...
by Duane Degn
Tue Jul 29, 2014 4:16 am
Forum: General discussion
Topic: The Pi NoIr can be used to see under the clothes?
Replies: 8
Views: 3488

Re: The Pi NoIr can be used to see under the clothes?

As has been mentioned in order to see body heat, you need a sensor capable of seeing in the far infrared range. With the wide availability of cameras capable of seeing in the near infrared this misconception about infrared equaling heat is slowly subsiding. In order for the Pi NoIr camera to see hea...
by Duane Degn
Sun Jul 27, 2014 10:11 pm
Forum: Automation, sensing and robotics
Topic: Pulse counting / outputing
Replies: 7
Views: 1313

Re: Pulse counting / outputing

There are probably lots of inexpensive microcontrollers which could do what you want at 500Hz. I think there are mainly two reasons one would want to use a Raspberry Pi for something like this. One reason would be you already know how to use the Raspberry Pi and it will save you time even though it'...
by Duane Degn
Sun Jul 27, 2014 5:17 pm
Forum: Automation, sensing and robotics
Topic: Pulse counting / outputing
Replies: 7
Views: 1313

Re: Pulse counting / outputing

Before I start... Do you guys think that this is possible. It will depend on the frequency. I don't know enough about the Pi to answer your question other than to say yes it is possible at low frequencies but to get a real answer you'll need to let us know what sort of frequency your hoping for. Ar...
by Duane Degn
Sat Jul 26, 2014 1:55 am
Forum: General discussion
Topic: A special kind of Clock
Replies: 16
Views: 2246

Re: A special kind of Clock

Can you tell us more about what you want the clock to do? So far, it sounds like an inexpensive microcontroller would be enough for this project. Of course, if you already know how to use the Raspberry Pi, then it would make sense to use what you already know how to use. A Raspberry Pi would offer a...
by Duane Degn
Fri Jul 25, 2014 6:59 pm
Forum: Automation, sensing and robotics
Topic: L293 dc motor - quick switch from forward to reverse problem
Replies: 6
Views: 2049

Re: L293 dc motor - quick switch from forward to reverse pro

Also how can I test the current/voltage during this motor switch condition, would a scope on the supply pins show the dip in voltage? Yes, I scope would likely show the dip in voltage. You don't need a short to cause this problem. Many of the suggestions already given should help. Can you tell us m...
by Duane Degn
Thu Jul 24, 2014 11:07 pm
Forum: Automation, sensing and robotics
Topic: Raspberry Pi portable night vision Wildlife nature camera
Replies: 2
Views: 1165

Re: Raspberry Pi portable night vision Wildlife nature camer

This looks like a great project.

I hope you share the photos you take with it.
by Duane Degn
Wed Jul 23, 2014 8:25 pm
Forum: Automation, sensing and robotics
Topic: L298N Motor driver help
Replies: 31
Views: 33878

Re: L298N Motor driver help

Alternatively you could just jumper ENA/B high and use PWM to control speed on the IN pins instead. That way only requires 2 gpios per motor. That works but it can sound awful as the motor does a "fast brake" with each low pulse. Apparently at high PWM frequencies (which don't work well on the L298...

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