In a previous article we looked at the scroll:bit, this is an add on from Pimoroni which contains a lot of LEDs, in fact there are 119 in total in a 17 x 7 matrix – its controlled by a IS31FL3731 LED matrix driver chip.
This is what the scroll:bit looks like fitted to a bpi:bit
Parts List
The scroll:bit costs about $18.99 from the US.
Here are a couple of links to the products
| Part | Link |
|---|---|
| Banana PI Bit board | Banana PI Bit board with ESP32 |
| scroll:bit | Pimoroni Scroll:bit |
Code
You need to to install the Adafruit_GFX and Adafruit_IS31FL3731 libraries, you can add these using the library manager.
The key thing is that the Featherwing version is the same size as the scroll:bit. So in the code you need to use
Adafruit_IS31FL3731_Wing ledmatrix = Adafruit_IS31FL3731_Wing();
These 2 examples work fairly well
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_IS31FL3731.h>
// If you're using the full breakout...
//Adafruit_IS31FL3731 ledmatrix = Adafruit_IS31FL3731();
// If you're using the FeatherWing version
Adafruit_IS31FL3731_Wing ledmatrix = Adafruit_IS31FL3731_Wing();
// The lookup table to make the brightness changes be more visible
uint8_t sweep[] = {1, 2, 3, 4, 6, 8, 10, 15, 20, 30, 40, 60, 60, 40, 30, 20, 15, 10, 8, 6, 4, 3, 2, 1};
void setup() {
Serial.begin(9600);
Serial.println("ISSI swirl test");
if (! ledmatrix.begin()) {
Serial.println("IS31 not found");
while (1);
}
Serial.println("IS31 found!");
}
void loop() {
// animate over all the pixels, and set the brightness from the sweep table
for (uint8_t incr = 0; incr < 24; incr++)
for (uint8_t x = 0; x < 16; x++)
for (uint8_t y = 0; y < 9; y++)
ledmatrix.drawPixel(x, y, sweep[(x+y+incr)%24]);
delay(20);
}and now for the second example
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_IS31FL3731.h>
// If you're using the full breakout...
//Adafruit_IS31FL3731 matrix = Adafruit_IS31FL3731(17,7);
// If you're using the FeatherWing version
Adafruit_IS31FL3731_Wing matrix = Adafruit_IS31FL3731_Wing();
static const uint8_t PROGMEM
smile_bmp[] =
{ B00111100,
B01000010,
B10100101,
B10000001,
B10100101,
B10011001,
B01000010,
B00111100 },
neutral_bmp[] =
{ B00111100,
B01000010,
B10100101,
B10000001,
B10111101,
B10000001,
B01000010,
B00111100 },
frown_bmp[] =
{ B00111100,
B01000010,
B10100101,
B10000001,
B10011001,
B10100101,
B01000010,
B00111100 };
void setup() {
Serial.begin(9600);
Serial.println("ISSI manual animation test");
if (! matrix.begin()) {
Serial.println("IS31 not found");
while (1);
}
Serial.println("IS31 Found!");
}
void loop() {
matrix.setRotation(0);
matrix.clear();
matrix.drawBitmap(3, 0, smile_bmp, 8, 8, 255);
delay(500);
matrix.clear();
matrix.drawBitmap(3, 0, neutral_bmp, 8, 8, 64);
delay(500);
matrix.clear();
matrix.drawBitmap(3, 0, frown_bmp, 8, 8, 32);
delay(500);
matrix.clear();
matrix.drawPixel(0, 0, 255);
delay(500);
matrix.clear();
matrix.drawLine(0,0, matrix.width()-1, matrix.height()-1, 127);
delay(500);
matrix.clear();
matrix.drawRect(0,0, matrix.width(), matrix.height(), 255);
matrix.fillRect(2,2, matrix.width()-4, matrix.height()-4, 20);
delay(500);
matrix.clear();
matrix.drawCircle(8,4, 4, 64);
matrix.drawCircle(8,4, 2, 32);
delay(500);
matrix.setTextSize(1);
matrix.setTextWrap(false); // we dont want text to wrap so it scrolls nicely
matrix.setTextColor(100);
for (int8_t x=0; x>=-32; x--) {
matrix.clear();
matrix.setCursor(x,0);
matrix.print("Hello");
delay(100);
}
matrix.setTextSize(2);
matrix.setTextWrap(false); // we dont want text to wrap so it scrolls nicely
matrix.setTextColor(32);
matrix.setRotation(1);
for (int8_t x=7; x>=-64; x--) {
matrix.clear();
matrix.setCursor(x,0);
matrix.print("World");
delay(100);
}
}
