ColorChord - A Steampunk inspired creation

A simple analog and digital device that enables the sight impaired to scan and hear the color of a selected object and plays music, sort of.

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In this case, to hear the color means to listen to the volume level of preset tones rather than hearing a word spoken from the scanner. ColorChord is a analog and digital device that will be easy to replicate by anyone using basic components and is intended to be used by the visually impaired, i.e. total blindness or a range of color blindness.

Think of it as a handheld audible spectrum analyzer.

The concept is that the device uses three CdS photo cells, each with its own color filter. Red, green and blue will be used for the filters.

There are three audio oscillators  using  different  preset frequencies .

The power to each oscillator is cycled by the sequencer.

The volume level from each oscillator is controlled by one of the filtered CdS cells.

The signals are then fed to a audio amplifier ( optional ) or directly to a ear phone.

The end user will hear a series of up to three tones with variable levels so that the user should be able to determine the scanned color based on the combination of tones and levels.

For training purposes, a wide range of color samples with braille and text labels will be provided.

  • 24 × 2n2222 / 549 npn transistor
  • 38 × 1n914 diode
  • 1 × Color filters Red, green and blue. Color ink markers on clear plastic works well. Filters cut to size to cover the CdS cells
  • 1 × 8 ohm speaker
  • 3 × LDR ( photo resistor ) from scraped night lights

View all 26 components

  • ColorChord plays music?

    Dr. Cockroach10/01/2018 at 00:31 0 comments

    This might be madness but ColorChord now has a three note cardboard color keyboard to play a very simple tune on. I have just managed to get the first crude keyboard to work.

    In the process of mounting the three color cards.

  • Block Diagram at long last

    Dr. Cockroach09/13/2018 at 19:04 0 comments

    I have finally gotten around to drawing the block diagram of ColorChord. There are few actual circuit drawings because anyone who wants to give this a try can choose what ever circuits they want to use for each section. I am sure that ColorChord can be reduced to palm size with a little bit of effort.

  • Final Video for the HackadayPrize

    Dr. Cockroach09/09/2018 at 22:48 0 comments

  • Top 20

    Dr. Cockroach09/06/2018 at 10:59 1 comment

    I just received word yesterday that ColorChord made it into the top 20 for the HCI challenge. Wow, I never thought it would go that direction and I was just about to scrap it for the parts to use on other projects. Guess not :-D

    Now I need to dust it off and tidy up some loose ends.

  • All construction is complete

    Dr. Cockroach07/01/2018 at 22:39 0 comments

    The wiring is complete as of July 1, 2018
    I will soon do a final update with the parts list and block diagram of the circuit.

  • Almost finished - Muahahaha

    Dr. Cockroach07/01/2018 at 08:12 0 comments

    ColorChord is just about finished. All it needs is a 9 volt battery installed and it will be final. For what it does, a single chip could have done but there is a lot of Love, Learning and Art in this project :-D

  • Timing and control board

    Dr. Cockroach06/26/2018 at 01:11 0 comments

    The board now has a working sequencer. The entire board had zero wiring errors and worked first time.

    The clock and master/slave flip-flop is wired and working and hard to believe no wiring errors so far.

    The timing and control board will have three sections. The master oscillator then the Master Slave Flip-Flop and then the Sequencer. All three will be on  4.5 X 6 inch cardboard.

    The Clock is a two transistor multi vibrator feeding into the Sequencer at about 20 Hz. The DTL circuit is adapted from the Tiny Tim CPU project by Rory Mangles. Sequencer outputs A, C and E were used for ColorChord.

  • Clock for ColorChord

    Dr. Cockroach06/25/2018 at 16:22 0 comments

    Just finished wiring up a new clock for ColorChord. Using the same circuit as used with IO but oh so much smaller and still on cardboard.

    Measures about half a cubic inch.

  • Sounds much better

    Dr. Cockroach06/24/2018 at 00:24 0 comments

    ColorChord is sounding much better now that I have separated the notes a bit. I have tied into IOs sequencer and added a buffer gate for each note.

  • Plan of action ?

    Dr. Cockroach06/21/2018 at 09:00 0 comments

    Well, let me think on this a bit.... I have been messing around with some very basic synthesizer and switching circuits and think that instead of all three tones playing a simultaneous chord, I will switch between the three so that each can be heard more clearly. All I need is to reduce the size of IOs clock and sequencer so as to fit with the handheld scanner.

View all 23 project logs

  • 1
    The basic building blocks

    There will not be a step by step for ColorChord. All sections can be built using many styles and selection of whatever components desired.

                         The building blocks are the following.

    1 - Audio oscillator. Three are required. I chose the 555 timer.

         Each oscillator is adjusted to a chosen frequency that relates

         to one of the three primary colors red, green or blue.

    2 - Clock. I used a two transistor astable multi-vibrator running

          between 10 and 20hz

    3 - Five step FSM sequencer. I used the first, third and fifth outputs.

         I choose DTL but 74xx TTL logic would save space.

    4 - Audio amp. I used a scraped unit from a CD player.

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Enjoy this project?



Daren Schwenke wrote 05/31/2018 at 03:23 point

I really like the idea, but I think using three 555 timers is going to drive anyone with pitch insane. The frequency is going to drift between them, which is going to detune your chord.

  Are you sure? yes | no

Dr. Cockroach wrote 05/31/2018 at 10:27 point

Ah but the pitch remains constant, just the volume level changes :-) Getting ready for a full test today I hope :-) Oh, I should add that if the oscillators de-tune over time then they can be adjusted if need be. That's the blue pots an the boards :-)

  Are you sure? yes | no

Daren Schwenke wrote 05/31/2018 at 14:20 point

I know your design intent... and I love that.  I'm just saying making three 555's be stable enough frequency references to allow them to generate chords without being out of tune, will be a challenge.  I did something very similar when I was trying to develop perfect pitch about 25 years ago, and the frequency drifted enough to make the 555 unusable for that purpose.

  Are you sure? yes | no

Dr. Cockroach wrote 05/31/2018 at 15:51 point

Oh, I get what you mean Daren, I hope the drift will not be a major problem and as this will be used  and powered up for brief periods of time that any drift will not be a major issue. At least for testing out the idea the 555s will be ok but the beauty of this circuit is that other oscillators can be used if need be and I just used the 555s as that is what I had and is a quick and dirty way to get it up and running :-) Any input from your end is most welcome :-)

  Are you sure? yes | no

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