I'm using the Adafruit 7 Segment LED Backpack in a project. But, when I connect it to the Tiny, it doesn't change at all. It has power, as the green light is on. It is running off of 5V, which is in its specification. It's not a problem with the display, as I tested it with CircuitPython on a Pi Pico (at 3V if that's important) and it worked fine. That leads me to believe it's a problem with the code. My code is below. It compiles without issue, and connecting an LED to flash at certain points, it is indeed running the code - but the display is not reacting. I have double checked my wiring and it is in the correct pins. The tiny is running at 1MHz. There are pull-up resistors built into the LED Backpack. Please help.
/* SevenSegTest_tiny
This is a demonstration of using the Adafruit 4-digit
7-segment LED backpack with an ATtiny uC.
http://www.adafruit.com/category/37_103
ht16
It requires the TinyWireM library for I2C communication
and the Tiny_LEDBackpack library for the various display
functions.
TinyWireM library obtained from http://www.scenelight.nl/?wpfb_dl=22
NOTE: Tested successfully on ATtiny85, using 4700ohm pull-up
resistors on SCL and SDA lines. Tested using 1MHz internal clock.
ATtiny85 physical pin7 --> SCL pin on LED Backpack
ATtiny85 physical pin5 --> SDA pin on LED Backpack
NOTE: Tested successfully on ATtiny84, using 4700ohm pull-up
resistors on SCL and SDA lines. Tested using 1MHz internal clock
ATtiny84 physical pin9 --> SCL pin on LED Backpack
ATtiny84 physical pin7 --> SDA pin on LED Backpack
Tested with and without AVRISP mkII hooked up, works fine both
ways.
Additionally tested on ATtiny84 using 8MHz internal clock. To
enable this functionality, you must alter the USI_TWI_Master.h
file in the TinyWireM library to run at 8MHz. Search for the
line near the top that reads:
#define SYS_CLK 1000.0 // [kHz] Default for ATtiny2313
and change the 1000 to 8000.
Also tested with 10k ohm pull-up resistors on SDA and SCL lines.
This demo also uses a regular LED attached to
ATtiny84 physical pin 2 (Arduino pin 10) to show
that the sketch is running.
*/
#include <TinyWireM.h>
#include <Tiny_LEDBackpack.h>
Tiny_7segment sevenseg = Tiny_7segment();
int led = 10; // indicator LED for ATtiny84. Connect with 100-470ohm resistor
#define i2c_addr 0x70 // stock address for Adafruit 7-segment LED backpack
void setup() {
pinMode(led, OUTPUT);
digitalWrite(led,HIGH);
delay(1500);
digitalWrite(led,LOW);
delay(300);
sevenseg.begin(i2c_addr); // initialize HT16K33 controller
// sevenseg.blinkRate(2); // set blink rate (0,1,2 or 3)
sevenseg.clear(); // clear all digits on display
sevenseg.writeDisplay(); // push data to display
delay(1000);
}
void loop(){
sevenseg.drawColon(true); // draw colon
sevenseg.writeDisplay(); // push data to display
delay(500);
// Example of writing a multi-digit integer to the display
sevenseg.print(1234); // print integer
sevenseg.writeDisplay(); // push data to display
delay(500);
// Example of writing a multi-digit floating point number
// to the display. The 2nd argument specifies
// how many digits to display after the decimal. Omit the
// 2nd argument for integer values.
sevenseg.print(56.7, 1); // print a floating point number
sevenseg.writeDisplay(); // push data to display
delay(500);
sevenseg.clear(); // clear display before writing raw digit
sevenseg.writeDisplay();
// Example of writing a single digit to a specified position on the
// display. The 1st argument is the digit position (0,1,3,4), 2nd
// value is the numeric value to display (0-9, a-F), and the 3rd
// value is whether to show the decimal point. Note that if you
// don't clear the display ahead of time, any previously displayed
// values in other digits will remain visible. Digit position 2 is
// the colon, so we don't try to write numbers to it.
sevenseg.writeDigitNum(3, 9, true); // position 3, value 9, show decimal)
sevenseg.writeDisplay(); // push the data to the display
delay(500);
//-----------------------------------------------------------------
// Example of a hard-coded write using the
// TinyWireM library by itself. This doesn't use the Tiny_LEDBackpack
// library at all.
// delay(100);
// TinyWireM.beginTransmission(0x70); // device address
// TinyWireM.send(0x02); // digit address (0x00, 0x02, 0x06, 0x08)
// TinyWireM.send(0x4F); // send bitmask for number to display
// TinyWireM.endTransmission(); // push data to display
// TinyWireM.beginTransmission(0x70); //device address
// TinyWireM.send(0x08); // starting address (4th digit = 0x08)
// TinyWireM.send(0x7F); // send bitmask for number to display
// TinyWireM.endTransmission(); // push data to display
//----------------------------------------------------------------
//----------------------------------------------------------------
// Hard coded example of turning on colon using TinyWireM library
// TinyWireM.beginTransmission(0x70);
// TinyWireM.send(0x04); // position of colon
// TinyWireM.send(0xFF); // send a 255 to turn on the colon
// TinyWireM.endTransmission(); // push data to display
// delay(500);
//----------------------------------------------------------------
//-----------------------------------------------------------------
// Bit mask codes. These can be used with writeDigitRaw to
// print various letters and symbols in a digit on the
// seven segment LED display.
// The first argument is the position
// on the 4-digit display, starting at 0 (far left),
// ending at 4 (far right), with position 2 being
// the colon (so you'll skip this position usually).
// The second argument is an integer that corresponds
// to the binary representation of the combination of
// 7 segments making up each digit.
// 0
// ------
// 5 | | 1
// | 6 |
// ------
// 4 | | 2
// | |
// ------ o7
// 3
// For example, to make upper case A, you want to
// light up segments 0,1,2,4,5,6.
// The binary representation would be b01110111.
// The bit positions are -->b76543210
// The corresponding integer value is 119 for A.
// Use a binary-to-decimal calculator to convert.
// Below is a list of codes for letters and symbols
// sevenseg.writeDigitRaw(0,119); // 119 = "A"
// sevenseg.writeDigitRaw(0,124); // 124 = "b"
// sevenseg.writeDigitRaw(0,57); // 57 = "C"
// sevenseg.writeDigitRaw(0,94); // 94 = "d"
// sevenseg.writeDigitRaw(0,121); // 121 = "E"
// sevenseg.writeDigitRaw(0,113); // 113 = "F"
// sevenseg.writeDigitRaw(0,125); // 125 = "G"
// sevenseg.writeDigitRaw(0,118); // 118 = "H"
// sevenseg.writeDigitRaw(0,116); // 116 = "h"
// sevenseg.writeDigitRaw(0,6); // 6 = "I" aka 1
// sevenseg.writeDigitRaw(0,4); // 4 = "i"
// sevenseg.writeDigitRaw(0,30); // 30 = "J"
// sevenseg.writeDigitRaw(0,56); // 56 = "L"
// sevenseg.writeDigitRaw(0,84); // 84 = "n"
// sevenseg.writeDigitRaw(0,92); // 92 = "o"
// sevenseg.writeDigitRaw(0,115); // 115 = "P"
// sevenseg.writeDigitRaw(0,103); // 103 = "q" aka 9
// sevenseg.writeDigitRaw(0,80); // 80 = "r"
// sevenseg.writeDigitRaw(0,109); // 109 = "S" aka 5
// sevenseg.writeDigitRaw(0,70); // 70 = "t"
// sevenseg.writeDigitRaw(0,28); // 28 = "u"
// sevenseg.writeDigitRaw(0,62); // 62 = "U"
// sevenseg.writeDigitRaw(0,110); // 110 = "y"
// sevenseg.writeDigitRaw(0,64); // 64 = "-" negative sign
// sevenseg.writeDigitRaw(0,34); // 34 = " " " double quote
// sevenseg.writeDigitRaw(0,32); // 32 = "'" apostrophe (upper left)
// sevenseg.writeDigitRaw(0,2); // 2 = "'" apostrophe (upper right)
// sevenseg.writeDigitRaw(0,8); // 8 = "_" underscore
// sevenseg.writeDigitRaw(0,1); // 1 = "-" overbar
// sevenseg.writeDigitRaw(0,16); // 16 = lower left bar
// sevenseg.writeDigitRaw(0,4); // 4 = lower right bar
// sevenseg.writeDigitRaw(0,128); // 128 = "." decimal
// sevenseg.writeDigitRaw(0,0); // blank
// sevenseg.writeDigitRaw(2,255); // 255 = ":" colon, always position 2
/* *********************
Always follow a writeDigitRaw command with the
writeDisplay(); command to push the data to the
display.
************************ */
// sevenseg.writeDisplay(); // push data to display
// Example using writeDigitRaw to write numbers or characters
// to specific digits on the display. This spells 'run'.
sevenseg.writeDigitRaw(0,80); // specify position and code, 80 = 'r'
sevenseg.writeDigitRaw(1,28); // specify position and code, 28 = 'u'
sevenseg.writeDigitRaw(3,84); // specify position and code, 84 = 'n'
sevenseg.writeDisplay(); // push data to display
delay(1000);
//---------------------------------------------------------------
// A cute trick to make a little "processing" indicator
// This will light each of the outer segments of a digit
// in series, making a rotating indicator. The outer
// segments are conveniently set up with bit mask values
// that are increasing multiples of 2.
sevenseg.clear();
sevenseg.writeDisplay();
for (int wait = 0; wait < 3; wait++) { // repeat multiple times
for (int i = 1; i < 64; i *= 2) {
sevenseg.writeDigitRaw(0,i);
sevenseg.writeDisplay(); // push data to display
delay(100);
}
}
//-----------------------------------------------------------------
// Another animation that lights each of the decimal points in
// succession.
for (int wait = 0; wait < 3; wait++) { // repeat multiple times
for (int i = 0; i < 5; i++) {
if (i == 2) i++; // This is needed to skip over position 2
sevenseg.writeDigitRaw(i,128); // light the decimal at position i
sevenseg.writeDisplay(); // push data to display
delay(100);
sevenseg.writeDigitRaw(i,0); // clear the decimal at position i
sevenseg.writeDisplay(); // push data to display
}
}
// Flash the external LED to indicate that the sketch is running
// in case the 7-segment LED display isn't working.
digitalWrite(led,HIGH);
delay(200);
digitalWrite(led,LOW);
delay(200);
}
Yes, I am just using the example code..
