Show Posts
Pages: 1 ... 31 32 [33] 34
481  Forum 2005-2010 (read only) / Exhibition / Re: Two Pushbuttons on One Input for More I/O on: July 09, 2010, 02:19:59 am
jdoll analog is such fun isn't it? :-D  smiley-razz

I can't see that being good for more than 4 inputs without time, pain and precision parts but it is an option. For more inputs you may need to calibrate them for various temperatures. The atmega168 and other atmel chips have a built in temperature sensor which may be of use if it's calibrated.

It is a lot of work but it is a cool hack. smiley
482  Forum 2005-2010 (read only) / Exhibition / Re: Random sound generator with water on: July 09, 2010, 02:26:07 am
Very nice!

I wonder if I poked one finger in could the waves be read to show where I'd touched? It would be slow but it could be a 'touch screen'  smiley
483  Forum 2005-2010 (read only) / Exhibition / Re: 32x32 led ghetto matrix :) on: July 09, 2010, 02:47:13 am
I used HEF4794 it can drive higher current per pin around 40ma though there are package limitations to running all outputs at max. You can pwm the output enable pin to control brightness.

Or you can use transistors or something like

Have fun.
484  Forum 2005-2010 (read only) / Exhibition / Re: How to write on DAC 0808 the perfect way? on: May 23, 2010, 01:40:13 pm
This needs to be moved to "Interfacing" ask a mod to move it so you'll get more responses.

That substitution will require a large rewrite of the arduino code from that page. It will also require some different hookups.

The reference design here calls for +5, +10V  and -15V and an op-amp that needs  + and - 18V and it's been discontinued.

The part in that other schematic yeilds 0-5v and is trivial to use.

You could use a resistor ladder dac. The example on the scope shows that the output will vary in steps but ones working you can design a filter to smooth that out

485  Forum 2005-2010 (read only) / Exhibition / Re: Gift for gf using Arduino on: December 20, 2007, 07:43:44 pm
Develop the project on the arduino. I suggest something simple with less but brighter LEDs. How about a music box that lights up and twinkles when opened? Five LEDs are easy and there's an extra pin for a button to tell when the box is open.

Then get a barebones board from modern devices and wire that up. You will need a chip with a boot loader and you can program it with your arduino then put it into the bare board.

486  Forum 2005-2010 (read only) / Exhibition / Re: Arduino Theremin (with PING sensor) on: December 26, 2007, 03:47:17 pm

Three articles about Arduino music, you'll be in 8bit heaven!
487  Forum 2005-2010 (read only) / Exhibition / Not silly! CLOCK CLOCK CLOCK on: December 26, 2007, 04:54:14 pm

Just some ideas you can use. smiley
488  Forum 2005-2010 (read only) / Exhibition / Re: Meter clock on: December 26, 2007, 04:33:12 pm
No it's not silly. I like odd projects like this.

Tape, glue or rivet a bunch of coils to a piece of plastic, make them in a 'seven segment' dot pattern. Have the plastic with the coils on the back drop down into some ferrite power (laser printers have it) and when it comes up it displays the time. smiley-wink

Then it lays back down, turns off the coils, turns them back on with the new time and raises again.


Of course I have a 120v fire alarm bell, a solid state relay and an arduino. I'll wake up Nixon! I've already pissed off the drunks on a Saturday with my testing. Opps.

Super silly!

489  Forum 2005-2010 (read only) / Exhibition / Re: Meter Information Station on: December 26, 2007, 04:04:41 pm
Generate a 60hz sine wave

Feed it to the appropriate audio amplifier amplifier. Control the volume with either a digital SPI pot or PWM.

Couple it to the meter with a non-polarized capacitor. Small non electrolytic one.

490  Forum 2005-2010 (read only) / Exhibition / Re: Reading Rotary Encoders - Ideas??? on: December 20, 2007, 07:39:07 pm
You hijacked this thread which really doesn't let people see you. I'd suggest putting this as a separate query in the forum.

I am also hoping to read several encoders -- I'll have two or three quadrature encoders, which means four or six signals to monitor. Any information about how well these parts work would be very helpful!

I do have one question: the datasheet for the ATmega168 suggests that in addition to the INT0 and INT1 interrupts which can be set to trigger on rising/falling/low (and which appear to be exposed in the Arduino software and covered by the various tutorials), there are PCINT0-23 interrupts that appear to trigger on pin changes for various pins. There are plenty of these: would they be usable for reading encoder signals? I'm (of course) a complete neophyte to this, so it's possible that I've completely misunderstood what the PCINT interrupts can be used for: if so, my apologies.
491  Forum 2005-2010 (read only) / Exhibition / Re: Reading Rotary Encoders - Ideas??? on: November 27, 2007, 09:40:24 pm
That seems very hard. You could interrupt the same pin for each of them but you'd also need to feed an address to the uC that would tell which unit triggered it. Sort of a MUX which would also inform the uC that there is data, it's from A/B/C etc

... later SPI I/O Expander with interrupt output.  This should allow you to use plenty. I didn't search for a breadboard compatible version. Maxim isn't the only one out there but I found more i2c ones than SPI ones.

492  Forum 2005-2010 (read only) / Exhibition / Re: plastic package for arduino board on: June 24, 2007, 07:21:20 pm
Your suggestion is just fine and it's easier to get that box in the US.

Wouldn't it be great if people like me switched to the metric system?  Sure would alleviate a lot of problems (simpler imo too).
493  Forum 2005-2010 (read only) / Exhibition / Re: 189014ctl - A controller on: June 24, 2007, 07:01:08 pm
Do you use the existing USB port? You could get one of the Arduino Serial USB Boards and mount it in a convenient place or use a front panel mount similar to this

For a cool retro look use an LED but face it with a small glass bead. smiley-wink
If you're a Star Trek fan you can use marbles glued over slightly smaller holes and back light them with an LED.  ;D

494  Forum 2005-2010 (read only) / Exhibition / Re: A(nother?) Successfull Matrix on: June 24, 2007, 07:24:11 pm
Have you thought of I2C or SPI eeproms? I've not looked at using them but they could be an option.

My goal is to be able to:
  • Store animation sequences in memory in a compact way, maybe even EEPROM.  This would work nicely because then a program could be written to accept new animations from the serial port and store them into some non-volatile memory somewhere.
  • Update display quite fast, minimizing flicker.  The eventual goal is a 8x8x8 matrix for display and recruiting for my Computer Science program -- a flickering display would be more impressive.  This is why I implemented the buffering mechanism which will allow for as few communications to the MAX chips as possible.  Thinking ahead now I might just go around the shift register functionality and use a multiplexer to program the individual chips as fast as possible.
495  Forum 2005-2010 (read only) / News / Re: Open source Project / Hardware on: July 12, 2007, 07:46:50 pm
The hardware is under a creative commons license but I'm unclear how the IDE is licensed nor how that effects the resulting binaries. I'm also unsure of the boot loaders license.

The Creative Commons license  seems allow selling it as long as you give the buyer the same rights you had to the hardware.

I am unclear if this means you must share source code or only have to give the binary program.

This is a good question.  

Hello, My Friends.

It's my first time discussing about a open source project/hardware and I'd like understand how it works, it means, if I create a tool, machine, device using Arduino, what do I have to do related with commercial or legal aspects?

I've been working with open source software and tools, but never with a hardware component.

My e-mail address is

Thanks for any help.  smiley-wink
Pages: 1 ... 31 32 [33] 34