Go Down

Topic: Practical Maker PWM shield issues on a MEGA 2560 (Read 2403 times) previous topic - next topic

cube

Hi all, I just bought a PWM shield from Practicalmaker.com to expand my PWM IO's to 32 instead of the base 14 you get with the MEGA.

Basically all I am trying to achieve is a lighting display made up of arrays (separately powered) and switched, all I want the MEGA and PWM shield to do is send the signal for the arrays to fade in/out or blink.

So I connected all my arrays to the IO's of the PWM shield and tried to run the 'basic use' sketch that Alex Leone has provided with/via the website. For starters the sketch won't compile which raised an eyebrow to begin with, and (I'm no expert) but the sketch calls for loops/files that are not there... :~

Has anyone else bought this shield? and have you got it to work?

AWOL

#1
Oct 28, 2011, 01:02 pm Last Edit: Oct 28, 2011, 01:57 pm by AWOL Reason: 1
Links?
Code?

cube

The link for the shield-

http://www.practicalmaker.com/content/pwm-shield-assembled

and is documentation-

http://www.practicalmaker.com/tutorials/pwm-shield-documentation

The code for basic use sketch(a night rider effect)-

/*
    Basic Pin setup:
    ------------                                  ---u----
    ARDUINO   13|-> SCLK (pin 25)           OUT1 |1     28| OUT channel 0
              12|                           OUT2 |2     27|-> GND (VPRG)
              11|-> SIN (pin 26)            OUT3 |3     26|-> SIN (pin 11)
              10|-> BLANK (pin 23)          OUT4 |4     25|-> SCLK (pin 13)
               9|-> XLAT (pin 24)             .  |5     24|-> XLAT (pin 9)
               8|                             .  |6     23|-> BLANK (pin 10)
               7|                             .  |7     22|-> GND
               6|                             .  |8     21|-> VCC (+5V)
               5|                             .  |9     20|-> 2K Resistor -> GND
               4|                             .  |10    19|-> +5V (DCPRG)
               3|-> GSCLK (pin 18)            .  |11    18|-> GSCLK (pin 3)
               2|                             .  |12    17|-> SOUT
               1|                             .  |13    16|-> XERR
               0|                           OUT14|14    15| OUT channel 15
    ------------                                  --------

    -  Put the longer leg (anode) of the LEDs in the +5V and the shorter leg
         (cathode) in OUT(0-15).
    -  +5V from Arduino -> TLC pin 21 and 19     (VCC and DCPRG)
    -  GND from Arduino -> TLC pin 22 and 27     (GND and VPRG)
    -  digital 3        -> TLC pin 18            (GSCLK)
    -  digital 9        -> TLC pin 24            (XLAT)
    -  digital 10       -> TLC pin 23            (BLANK)
    -  digital 11       -> TLC pin 26            (SIN)
    -  digital 13       -> TLC pin 25            (SCLK)
    -  The 2K resistor between TLC pin 20 and GND will let ~20mA through each
       LED.  To be precise, it's I = 39.06 / R (in ohms).  This doesn't depend
       on the LED driving voltage.
    - (Optional): put a pull-up resistor (~10k) between +5V and BLANK so that
                  all the LEDs will turn off when the Arduino is reset.

    If you are daisy-chaining more than one TLC, connect the SOUT of the first
    TLC to the SIN of the next.  All the other pins should just be connected
    together:
        BLANK on Arduino -> BLANK of TLC1 -> BLANK of TLC2 -> ...
        XLAT on Arduino  -> XLAT of TLC1  -> XLAT of TLC2  -> ...
    The one exception is that each TLC needs it's own resistor between pin 20
    and GND.

    This library uses the PWM output ability of digital pins 3, 9, 10, and 11.
    Do not use analogWrite(...) on these pins.

    This sketch does the Knight Rider strobe across a line of LEDs.

    Alex Leone <acleone ~AT~ gmail.com>, 2009-02-03 */

#include "Tlc5940.h"

void setup()
{
  /* Call Tlc.init() to setup the tlc.
     You can optionally pass an initial PWM value (0 - 4095) for all channels.*/
  Tlc.init();
}

/* This loop will create a Knight Rider-like effect if you have LEDs plugged
   into all the TLC outputs.  NUM_TLCS is defined in "tlc_config.h" in the
   library folder.  After editing tlc_config.h for your setup, delete the
   Tlc5940.o file to save the changes. */

void loop()
{
  int direction = 1;
  for (int channel = 0; channel < NUM_TLCS * 16; channel += direction) {

    /* Tlc.clear() sets all the grayscale values to zero, but does not send
       them to the TLCs.  To actually send the data, call Tlc.update() */
    Tlc.clear();

    /* Tlc.set(channel (0-15), value (0-4095)) sets the grayscale value for
       one channel (15 is OUT15 on the first TLC, if multiple TLCs are daisy-
       chained, then channel = 16 would be OUT0 of the second TLC, etc.).

       value goes from off (0) to always on (4095).

       Like Tlc.clear(), this function only sets up the data, Tlc.update()
       will send the data. */
    if (channel == 0) {
      direction = 1;
    } else {
      Tlc.set(channel - 1, 1000);
    }
    Tlc.set(channel, 4095);
    if (channel != NUM_TLCS * 16 - 1) {
      Tlc.set(channel + 1, 1000);
    } else {
      direction = -1;
    }

    /* Tlc.update() sends the data to the TLCs.  This is when the LEDs will
       actually change. */
    Tlc.update();

    delay(75);
  }

}

Go Up