Orologio Nixie: 3 – RTC ed expander

luca 16/03/2012 11

In questo terzo articolo, vedremo lo schema logico dell’orologio e due componenti fondamentali: il real time clock per mantenere l’orario e l’expander per avere a disposizione più linee di I/O.

Schema logico

Vediamo i componenti fondamentali dell’orologio:

  • Un modulo alimentazione con uscite 5V (per la logica) e 170V (per le Nixie);
  • un Arduino Mini per coordinare i vari elementi;
  • un modulo per la gestione di contatti a sfioramento (argomento di un prossimo post);
  • un modulo RTC connesso via bus I2C;
  • un integrato per espandere il numero di porte I/O, anch’esso via I2C;
  • quattro integrati 74141 per il controllo delle Nixie;
  • quattro tubi Nixie ZM1177.

Di seguito vedremo in dettaglio due di questi elementi…

Pagine: 1 2 3 4

11 Comments »

  1. pitchoilcan 06/04/2012 at 06:19 - Reply

    I get :error:
    PCF8575_Led_rolling_Demo.cpp: In function ‘void loop()’:
    PCF8575_Led_rolling_Demo.cpp:24:8: error: ‘class TwoWire’ has no member named ‘write’
    PCF8575_Led_rolling_Demo.cpp:25:8: error: ‘class TwoWire’ has no member named ‘write’
    I able to compile by change it for
    Wire.write(low);
    Wire.write(high);
    to
    Wire.send(low);
    Wire.send(high);
    but still now a blink from any of the LED’s. Are you using any resistor? I”ve tryed it using just the pcf8575 anf an arduino board, no RTC module. Is that doable and if so what I’m I doing wrong?

    • luca 10/04/2012 at 08:07 - Reply

      Hi

      You’re probably using an older (< 1.0) version of Arduino IDE… anyway you don’t need a RTC module for this example, could you post your connections so I can check?

  2. pitchoilcan 06/04/2012 at 07:15 - Reply
  3. Fernando Garcia 25/12/2012 at 18:27 - Reply

    Hello!

    I’m trying to build a circuit with a RTC and a PCF8575 .

    It happens that the RTC does not tell the correct time.
    There must be some conflict.

    The code I’m using to test is this:
    […]

  4. Fernando Garcia 25/12/2012 at 18:43 - Reply

    The code does not appear correctly.

    Here’s a link to it.

    https://gist.github.com/21dfdc057cfbd1cc44a9/5e7c42002b4025b9d48a21896d81c9a6bd74cbba

    Best regards.

    • luca 11/01/2013 at 08:32 - Reply

      Hi Fernando,

      are you using an Arduino Mega?

  5. Dmitry 19/03/2015 at 09:15 - Reply

    Hello Luca.
    Thanx for your manual!

    Could you advise IO extender on 24 pins (for 6 tubes)?

    I’ve found the Tca6424rgjr but probably there is something better.

    • luca 19/03/2015 at 11:15 - Reply

      Hi Dmitry… it depends on you: on the I2C bus you can connect more than one expander, therefore you can use 3 8-pins expanders or the one you found that works fine!

  6. DRS 30/11/2015 at 11:50 - Reply

    Hi, where i can read more about power supply ?
    Thx.

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