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Numerical output from a single LED

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  Numerical output from a single LED John Speth <johnspeth@yahoo.com> - 2019-12-26 11:51 -0800
    Re: Numerical output from a single LED Paul Rubin <no.email@nospam.invalid> - 2019-12-26 12:21 -0800
    Re: Numerical output from a single LED Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2019-12-26 16:44 -0500
    Re: Numerical output from a single LED Theo <theom+news@chiark.greenend.org.uk> - 2019-12-26 22:59 +0000
      Re: Numerical output from a single LED upsidedown@downunder.com - 2019-12-27 06:53 +0200
    Re: Numerical output from a single LED Paul Rubin <no.email@nospam.invalid> - 2019-12-26 15:33 -0800
    Re: Numerical output from a single LED Rick C <gnuarm.deletethisbit@gmail.com> - 2019-12-26 23:29 -0800
      Re: Numerical output from a single LED Richard Damon <Richard@Damon-Family.org> - 2019-12-27 10:42 -0500
    Re: Numerical output from a single LED Robert Roland <fake@ddress.no> - 2019-12-27 18:10 +0100
      Re: Numerical output from a single LED Paul Rubin <no.email@nospam.invalid> - 2019-12-27 11:13 -0800
    Re: Numerical output from a single LED Mike Perkins <spam@spam.com> - 2019-12-27 20:20 +0000
    Re: Numerical output from a single LED Paul Rubin <no.email@nospam.invalid> - 2019-12-27 13:55 -0800
      Re: Numerical output from a single LED Rick C <gnuarm.deletethisbit@gmail.com> - 2019-12-27 17:54 -0800
        Re: Numerical output from a single LED Paul Rubin <no.email@nospam.invalid> - 2019-12-28 01:07 -0800
          Re: Numerical output from a single LED Rick C <gnuarm.deletethisbit@gmail.com> - 2019-12-28 08:24 -0800
            Re: Numerical output from a single LED Phil Martel <pomartel@comcast.net> - 2019-12-30 10:16 -0500
    Re: Numerical output from a single LED Clifford Heath <no.spam@please.net> - 2019-12-29 12:32 +1100

#28958 — Numerical output from a single LED

I'm working on a project in which the hardware is already designed. The 
customer added a late stage requirement to output a numerical counter 
value. The only output port is a single three-color (RGB) LED.

Does anybody have any ideas how one might drive the LED to output a 
numerical value?

The device is a single purpose hand held grocery labeler and we want to 
count labels dispensed. The counter would not exceed 50,000 labels.

In the past, I've experimented with single LED numerical output by 
flashing the LED for each digit. The user must pay strict attention to 
the LED without blinking to count flashes accurately.  It takes practice 
to get right. I have not been able to find even a hint of possible 
methods using Google.

Thanks - JJS

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#28959

John Speth <johnspeth@yahoo.com> writes:
> In the past, I've experimented with single LED numerical output by
> flashing the LED for each digit. The user must pay strict attention to
> the LED without blinking to count flashes accurately.

That is crazy and unworkable.  How about having some kind of operation
to print a label giving the printer status including the number of
labels printed.

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#28960

On 2019-12-26 14:51, John Speth wrote:
> I'm working on a project in which the hardware is already designed. The 
> customer added a late stage requirement to output a numerical counter 
> value. The only output port is a single three-color (RGB) LED.
> 
> Does anybody have any ideas how one might drive the LED to output a 
> numerical value?
> 
> The device is a single purpose hand held grocery labeler and we want to 
> count labels dispensed. The counter would not exceed 50,000 labels.
> 
> In the past, I've experimented with single LED numerical output by 
> flashing the LED for each digit. The user must pay strict attention to 
> the LED without blinking to count flashes accurately.  It takes practice 
> to get right. I have not been able to find even a hint of possible 
> methods using Google.
> 
> Thanks - JJS

Have the user whirl it around on its cable, and output alphanumeric data 
in Morse code.  Or sell them a phone app to do it via the camera.

"Late stage requirement", forsooth.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

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#28961

John Speth <johnspeth@yahoo.com> wrote:
> I'm working on a project in which the hardware is already designed. The 
> customer added a late stage requirement to output a numerical counter 
> value. The only output port is a single three-color (RGB) LED.
> 
> Does anybody have any ideas how one might drive the LED to output a 
> numerical value?
> 
> The device is a single purpose hand held grocery labeler and we want to 
> count labels dispensed. The counter would not exceed 50,000 labels.

I can't think of a way to make it user friendly, but you could use the RGB
LED to output a binary number, using additional colours to aid in
synchronisation.

For example, LED goes blue for a 1, green for a 0.  In each pulse there's a
flash of red to indicate a bit transition and prevent bits merging into each
other.  The 4 bit binary code 1011 would be:

black (inter-sequence gap)
blue then magenta (1)
green then yellow (0)
blue then magenta (1)
blue then magenta (1)
black (end of sequence)

Someone with a user manual and a pen and paper could probably write that
sequence down, but it wouldn't be very pleasant.  You'd also need the
colours to be well distinguishable - often this needs tweaking series
resistors to get the colours of the different LEDs to match brightness.

Another option would be to write a basic phone app that uses the camera to
decode the sequence.  Or, alternatively, another means of signalling
directly to the app (much higher bandwidth available).

Other kinds of self-synchronising line codes would also work, but none of
them are very human friendly.

Theo

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#28963

On 26 Dec 2019 22:59:36 +0000 (GMT), Theo
<theom+news@chiark.greenend.org.uk> wrote:

>John Speth <johnspeth@yahoo.com> wrote:
>> I'm working on a project in which the hardware is already designed. The 
>> customer added a late stage requirement to output a numerical counter 
>> value. The only output port is a single three-color (RGB) LED.
>> 
>> Does anybody have any ideas how one might drive the LED to output a 
>> numerical value?
>> 
>> The device is a single purpose hand held grocery labeler and we want to 
>> count labels dispensed. The counter would not exceed 50,000 labels.
>
>I can't think of a way to make it user friendly, but you could use the RGB
>LED to output a binary number, using additional colours to aid in
>synchronisation.
>
>For example, LED goes blue for a 1, green for a 0.  In each pulse there's a
>flash of red to indicate a bit transition and prevent bits merging into each
>other.  The 4 bit binary code 1011 would be:
>
>black (inter-sequence gap)
>blue then magenta (1)
>green then yellow (0)
>blue then magenta (1)
>blue then magenta (1)
>black (end of sequence)

A color blind person might have problems decoding these colors. There
are many different kinds of color blindness. not just red/green,

>
>Someone with a user manual and a pen and paper could probably write that
>sequence down, but it wouldn't be very pleasant.  You'd also need the
>colours to be well distinguishable - often this needs tweaking series
>resistors to get the colours of the different LEDs to match brightness.
>
>Another option would be to write a basic phone app that uses the camera to
>decode the sequence.  Or, alternatively, another means of signalling
>directly to the app (much higher bandwidth available).
>
>Other kinds of self-synchronising line codes would also work, but none of
>them are very human friendly.
>
>Theo

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#28962

John Speth <johnspeth@yahoo.com> writes:
> The device is a single purpose hand held grocery labeler and we want
> to count labels dispensed. The counter would not exceed 50,000 labels.

Building on Theo's suggestion, if the idea is just for the operator to
know how close the counter is to 50k:

1) steady green = 0 to 25k labels printed
2) blinking green = 25k to 40k
3) steady orange = 40k to 45k
4) blinking orange = 45k to 49k
5) blinking red = 49k to 50k
6) steady red = 50k, printer cannot operate

Use the receipt printer or a phone app to get the exact number out if
desired.  The printer can print human readable numbers and/or a QR code
that a phone app can scan, allowing easy tracking of the activity of the
different printers.

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#28964

On Thursday, December 26, 2019 at 2:51:44 PM UTC-5, John Speth wrote:
> I'm working on a project in which the hardware is already designed. The 
> customer added a late stage requirement to output a numerical counter 
> value. The only output port is a single three-color (RGB) LED.
> 
> Does anybody have any ideas how one might drive the LED to output a 
> numerical value?
> 
> The device is a single purpose hand held grocery labeler and we want to 
> count labels dispensed. The counter would not exceed 50,000 labels.
> 
> In the past, I've experimented with single LED numerical output by 
> flashing the LED for each digit. The user must pay strict attention to 
> the LED without blinking to count flashes accurately.  It takes practice 
> to get right. I have not been able to find even a hint of possible 
> methods using Google.
> 
> Thanks - JJS

I think you could make this work.  Rather than flashing directly in decimal, I would have it flash a bi-quinary code.  For each digit have it first flash one or two times for the binary part and then flash the 1 to 6 times for the quinary part.  I think the flashing should be a bit rapid so as to make it easier to count without blinking.  

Still, there could be some confusion between the binary part and the quinary part.  Two flashes, two flashes, two flashes, two flashes, one flash, one flash...  At some point you can lose your place in the sequence of digits.  Maybe make the binary flashes longer since there will only be one or two.  Long pause between digits, shorter pause between the binary and quinary parts, very short pause between flashes within a bit or quint. 

-- 

  Rick C.

  - Get 1,000 miles of free Supercharging
  - Tesla referral code - https://ts.la/richard11209

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#28965

On 12/27/19 2:29 AM, Rick C wrote:
> On Thursday, December 26, 2019 at 2:51:44 PM UTC-5, John Speth wrote:
>> I'm working on a project in which the hardware is already designed. The
>> customer added a late stage requirement to output a numerical counter
>> value. The only output port is a single three-color (RGB) LED.
>>
>> Does anybody have any ideas how one might drive the LED to output a
>> numerical value?
>>
>> The device is a single purpose hand held grocery labeler and we want to
>> count labels dispensed. The counter would not exceed 50,000 labels.
>>
>> In the past, I've experimented with single LED numerical output by
>> flashing the LED for each digit. The user must pay strict attention to
>> the LED without blinking to count flashes accurately.  It takes practice
>> to get right. I have not been able to find even a hint of possible
>> methods using Google.
>>
>> Thanks - JJS
> 
> I think you could make this work.  Rather than flashing directly in decimal, I would have it flash a bi-quinary code.  For each digit have it first flash one or two times for the binary part and then flash the 1 to 6 times for the quinary part.  I think the flashing should be a bit rapid so as to make it easier to count without blinking.
> 
> Still, there could be some confusion between the binary part and the quinary part.  Two flashes, two flashes, two flashes, two flashes, one flash, one flash...  At some point you can lose your place in the sequence of digits.  Maybe make the binary flashes longer since there will only be one or two.  Long pause between digits, shorter pause between the binary and quinary parts, very short pause between flashes within a bit or quint.
> 

There are lots of ways to try to encode the value in a flashing light. 
One options that I have done similar to your bi-quinary is output a long 
dash for 5, and then short dashes for 1-4, you could change colors for 
different places, and so on. The long dash is easier to count than 5 
extra short flashes, but how every you do it, it will be a pain if you 
need the exact number up to 50,000 (do they REALLY need to distinguish 
between 45675 and 45676?)

I do like the other suggestion of just outputting a crude status on the 
led (use the color and maybe a simple flash code for the basic range) 
and then give a way to print the exact count.

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#28966

On Thu, 26 Dec 2019 11:51:39 -0800, John Speth <johnspeth@yahoo.com>
wrote:

>Does anybody have any ideas how one might drive the LED to output a 
>numerical value?

Transmit as serial data. Sell them a device that they can hold up to
the LED to read the data and display the number.

>The device is a single purpose hand held grocery labeler and we want to 
>count labels dispensed. The counter would not exceed 50,000 labels.

Simply print the number on the label?
-- 
RoRo

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#28967

Robert Roland <fake@ddress.no> writes:
> Transmit as serial data. Sell them a device that they can hold up to
> the LED to read the data and display the number.

A phone app could also do that, if the baud rate was slow enough for the
phone camera to keep up.

This type of late requirement change indicates a flaky customer but I
guess that is par for the course.

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#28968

On 26/12/2019 19:51:39, John Speth wrote:
> I'm working on a project in which the hardware is already designed. The 
> customer added a late stage requirement to output a numerical counter 
> value. The only output port is a single three-color (RGB) LED.
> 
> Does anybody have any ideas how one might drive the LED to output a 
> numerical value?
> 
> The device is a single purpose hand held grocery labeler and we want to 
> count labels dispensed. The counter would not exceed 50,000 labels.
> 
> In the past, I've experimented with single LED numerical output by 
> flashing the LED for each digit. The user must pay strict attention to 
> the LED without blinking to count flashes accurately.  It takes practice 
> to get right. I have not been able to find even a hint of possible 
> methods using Google.
> 
> Thanks - JJS

Can you make one of the LEDs imitate a bar code?

Optical RS232? Sell a reader too!

-- 
Mike Perkins
Video Solutions Ltd
www.videosolutions.ltd.uk

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#28969

John Speth <johnspeth@yahoo.com> writes:
> (RGB) LED.  Does anybody have any ideas how one might drive the LED to
> output a numerical value?

Resistor color code!  Black, brown, red, orange ...

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#28970

On Friday, December 27, 2019 at 4:55:53 PM UTC-5, Paul Rubin wrote:
> John Speth <johnspeth@yahoo.com> writes:
> > (RGB) LED.  Does anybody have any ideas how one might drive the LED to
> > output a numerical value?
> 
> Resistor color code!  Black, brown, red, orange ...

That might work.  A brief flash of bright white followed by a more sustained color flash.  Still, it can be hard to tell orange from red or blue from green or violet.  It used to be hard with resistors if they were creative with the exact color used.  As someone else pointed out, colors don't work if you are color blind and lots of people are.  

Still, this could be an interesting thing to try to develop.  

Rather than bi-quinary, it might work better to try three and four.  Longer flashes for the multiples of three, followed by shorter flashes for the units.  long, long, short, short gives 8.  

Or maybe Morse code.  Looks like they used a Johnson ring counter sort of code with a 1 being a single dot with four dashes.  2 is two dots and three dashes and so forth until a 6 is one dash followed by four dots.  7 is two dashes followed by three dots, etc.  Zero is all dashes taking the place of ten like on a phone dial.  lol 

I like the Morse code idea best of any I've seen here so far. 

-- 

  Rick C.

  + Get 1,000 miles of free Supercharging
  + Tesla referral code - https://ts.la/richard11209

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#28971

Rick C <gnuarm.deletethisbit@gmail.com> writes:
> I like the Morse code idea best of any I've seen here so far. 

If this is for use by store clerks, every idea suggested so far is in
forgeddabout it territory.  If it's for use by a technician who
maintains the equipment then these manual methods are too much hassle
even if they are doable, and the label guns should really upload their
status into a computer somehow.  That can be done by whatever medium
is used to program prices or skus or whatever else is in the guns.

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#28972

On Saturday, December 28, 2019 at 4:07:04 AM UTC-5, Paul Rubin wrote:
> Rick C <gnuarm.deletethisbit@gmail.com> writes:
> > I like the Morse code idea best of any I've seen here so far. 
> 
> If this is for use by store clerks, every idea suggested so far is in
> forgeddabout it territory.  If it's for use by a technician who
> maintains the equipment then these manual methods are too much hassle
> even if they are doable, and the label guns should really upload their
> status into a computer somehow.  That can be done by whatever medium
> is used to program prices or skus or whatever else is in the guns.

Not really.  Back in the day my mom learned to use a slide rule when working in a factory.  If it's part of the job you do every day it's no big deal for someone to learn that three short and two long means the digit 3.  

Geeze!  Look at all the damn blinking lights in use today.  PCs used to beep codes for boot errors.  Even devices with hugely complex interfaces will have blinking lights with very specific meanings depending on just what they are doing.  Even my Tesla uses a tiny icon with a red light to indicate the media for storing video is ready.  Then there are several other states I don't remember because I don't see them on a regular basis. 

Something like this a person sees every day will be second nature after a bit.  

Actually the best idea is to print a label with the count, but I assume there is a reason why that isn't being done as it is a rather simple and obvious solution. 

-- 

  Rick C.

  -- Get 1,000 miles of free Supercharging
  -- Tesla referral code - https://ts.la/richard11209

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#28984

On 12/28/2019 11:24, Rick C wrote:
> On Saturday, December 28, 2019 at 4:07:04 AM UTC-5, Paul Rubin wrote:
>> Rick C <gnuarm.deletethisbit@gmail.com> writes:
>>> I like the Morse code idea best of any I've seen here so far.
>>
>> If this is for use by store clerks, every idea suggested so far is in
>> forgeddabout it territory.  If it's for use by a technician who
>> maintains the equipment then these manual methods are too much hassle
>> even if they are doable, and the label guns should really upload their
>> status into a computer somehow.  That can be done by whatever medium
>> is used to program prices or skus or whatever else is in the guns.
> 
> Not really.  Back in the day my mom learned to use a slide rule when working in a factory.  If it's part of the job you do every day it's no big deal for someone to learn that three short and two long means the digit 3.
> 
> Geeze!  Look at all the damn blinking lights in use today.  PCs used to beep codes for boot errors.  Even devices with hugely complex interfaces will have blinking lights with very specific meanings depending on just what they are doing.  Even my Tesla uses a tiny icon with a red light to indicate the media for storing video is ready.  Then there are several other states I don't remember because I don't see them on a regular basis.
> 
> Something like this a person sees every day will be second nature after a bit.
> 
> Actually the best idea is to print a label with the count, but I assume there is a reason why that isn't being done as it is a rather simple and obvious solution.
> 
If you only want to express numbers, Morse code is inefficient.  "Dits" 
for 1 - 4 with a "Dah" at the beginning for 5 - 9 and a double "Dah" for 
0 would be faster, and equally easy for a person who doesn't know Morse.

-- 
Best wishes,
--Phil
pomartel At Comcast(ignore_this) dot net

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#28981

On 27/12/19 6:51 am, John Speth wrote:
> I'm working on a project in which the hardware is already designed. The 
> customer added a late stage requirement to output a numerical counter 
> value. The only output port is a single three-color (RGB) LED.
> 
> Does anybody have any ideas how one might drive the LED to output a 
> numerical value?

> In the past, I've experimented with single LED numerical output by 
> flashing the LED for each digit. The user must pay strict attention to 
> the LED without blinking to count flashes accurately.  It takes practice 
> to get right. I have not been able to find even a hint of possible 
> methods using Google.


That's exactly what Bosch did in the Motronic ML4.1 fuel injection 
system in the Alfa 75 Twin Spark (and probably other cars). It outputs 
fault codes if booted while a button is pressed. Useful if you don;t 
have a proper fault code reader.

It's tedious, but it does work. You can re-run the process multiple 
times if you miss a code.

Clifford Heath.

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