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allObjects

Member since Jul 2014 • Last active Dec 2018

Espruino makes IoT as easy as 123!

Most recent activity

  • in Puck.js, Pixl.js and MDBT42
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    @Marty_McFly,

    'scan' them out

    means exactly what you are saying.

    @Gordon suggested to let the scan run free to reduce the flicker - see Driving LED matrix with shift registers such as 74HC595 and Retro Bubble Displays driven with 74HC595. I used timeouts how long I would turn on a segment (and how much to wait after turning it of and turn on the next segment). Free running gives the eye the most snapshot like image of all segments. On the other hand - if you can afford from brightness / dimness - you could think of timing the next free run to save battery. Without, one segment would be always on and be the determining factor for power consummation.

  • in Projects
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    @SergeP, I think that for a clock the startup noise is not really a problem, because a clock is usually started rarely and tried to be kept up as long as possible. To avoid noise, you could think of adding some power control of the neopixels.

    According to NeoPixel WS2812 data sheet (as attached as .pdf), control logic and LEDs have separate power supply. That would be ideal to blank the LEDs. For clean start, power the control and keep the LEDs unpowered until after sending reset followed by complete string of desired data.

    It may not be possible with the boards you have, because most follow the simple approach and power the control logic locally for each pixel locally. This is reflected in the sample circuit in the data sheet.

    To prevent a reset - or other blocking tasks - while a send is going on, make the reset application controlled - and delay it until after all data has been sent.

    Since most neopixel products do not use the two power lines approach, you may not power the neopixels until all other things have completed the start up, then power the neopixels and send right away a reset and (blanking) data stream that you have prepared beforehand. This way you can minimize the noise moment.

  • in Projects
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    @user95697, micro:bit is extremely memory stricken... so, not much to the point to log data in memory for even decent time. Yes, you can apply all kinds of trickery / technology to compress the information (delta recording, etc), but that just grows the amount of code, which eats into the memory too.

    Not for nothing are peripherals available on busses.

    Therefore, I suggest that you look into external memory to log data onto. Some serial memory - which is also quite cheap and has plenty of space - where you can log the data, and even then pull and read it directly in some other device. Since you have plenty of target memory and it is time series, you can think of do round-robin / ring storage. You have enough memory for storing the meta / management data to efficiently handle the logging and communication.

  • in Interfacing
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    ...just add one more neopixel in front of the chain and enclose it... sometimes 'the solution' is not really a solution but resolves the issue (@Robin: ...even thoug I looked at the fix in Makuna's code...).

  • in Interfacing
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    @George, amazing... about 6 months ago I looked thru options to try a nixie clock - driven with an Espruino and port expander / shift register (and of course, 'high'-voltage drivers) ... but these original nixies as well as the red bubble LED displays are disappearing like extinct species... About the bubble displays I have posted and someone else actually is building this watch w/ a bank of four of these red bubble displays.

    On the Web I found a site about a place that produces new ones... and not just nixies, but also regular one... just not affordable for people like me. Getting a good stash yourself was a smart move...

    Looking forward to see your project come to completion...

    ...the fix @MaBe posted is really interesting, but not suitable in my case.

    May be it could be: just get an additional RGB LED and place it 'in front' of the one you have to have working (I see one under and between each of the nixies).

    Thank you for the great pictures.

  • in Projects
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    Sow what can make is kind of a jeopardy game, where the game console then advertises the question to the gamer pixls. The gamer pixls are preloaded with the questions, multiple choice answers, which the players then can pick from as soon as displayed. The time from display to answering - and of course the right answer give the ranking / negative points after back-advertising the group id and time.. and picked up by the gaming console. The audience would huddle as groups of 3..5.

  • in Interfacing
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    @George, I did some more adjustments... and added details. Yes, it is quite a finicky thing... but when you solder R83 and R2X upright only at one end onto the pads of R83, T1 also upright with Collector and Emitter straddling Q1's Basis and Emitter, and finally connect with two thin strands from a stranded wire what has to be connected, it could work... but as said: it is really finicky. Since you have not a free chain of RGB LEDs, you unfortunately cannot sacrifice one... otherwise, @MaBe's cool suggestion could be the 'perfect' solution (...ah fix...(:/...

    Btw, where did you get the nixie thing from, and what tubes are you using?

  • in Interfacing
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    @George, I guess that's the area of interest, as attached in pic.

  • in Interfacing
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    @MaBe, nice!

    I though think it should not be that difficult to do some air wiring. @George, could you pub a pic of you PCB?

  • in Projects
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    It all depends...

    Will a) some of the audience have most of these pixls in their hand? - or b) all the pixls shown by a camera on a screen? - How big will the audience be - assumed it is an 'in person' event?

    How much time do you have available until the presentation?

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