Arduino library to control Texas Instruments TIL306 (decimal point on left) and TIL307 (decimal point on right) numeric LED displays.

As few as one or as many as four output pins are needed to control the display, as noted below:

If any of the optional pins are hardwired, use TIL306::NO_PIN as the pin number in the constructor.

The decimal point (LED pin 13) is not controlled by the library, and may be controlled with a regular OUTPUT pin separately. One pin is needed for each LED digit. If you do not need to control the decimal point, tie it LOW to keep it off or HIGH to keep it on (do not leave it floating).

To control the level of the display's intensity, connect a PWM-capable pin to BI. The intensity() method can be use to set the brightness level, with 255 being brightes and 0 turning the display off.

If a non-PWM-capable pin is connected to BI, then use the blank() method to turn the display on (true) or off (false).

Refer to the sketch in the examples folder.

1. Include the library header file:

   #include "TIL306.h"

2. Instantiate the object.

   myLED = TIL306(byte CLK, byte BI, byte CLR, byte LS);

3. Initialize and prepare the display:

   myLED.begin();             // Initialize the objec
   myLED.blank(false);        // Turn on the display
   myLED.latch_strobe(true);  // Display latch is loaded with counter value

4. Methods to control the display:

   void increment(byte val);   // increments the display by val counts
   void intensity(byte val);   // 255 = display fully on, 0 = display off
   void blank(bool v);         // true = display off, false = display on
   void clear(bool v);         // true = set counter to zero, false = normal counting
   void clear_counter();       // sends a low-high pulse to clear the counter
   void latch_strobe(bool v);  // true = display matches counter, false = counter updates without changing display
   void print(uint32_t val);   // write val to the display right-justified; extra digits truncated
   void print(const char* s);  // Converts s to an integer and displays the integer

EX1_Demo.ino
Runs through various display control examples using all of the library methods.

Internal to the LED, there is a BCD counter that is updated by the CLK signal. Each rising clock edge increments the counter by one. This counter data is loaded into the LED segment display latches depending on the LS signal. By controlling the LS signal, the display can be updated to an arbitray number without having each intermediate value display while clocking in the new digit.

The other control signals on the LED are not used by the library. Consult the datasheet and application note for details. A few common configurations are described below.

None of the input signals on the LED should be left floating; each of them should be tied either HIGH or LOW depending on the configuration.

Below are some typical display configurations that can be used with the library, from a minimal-pin single digit operation all the way to full control of a multi-digit diplay.

This configuration uses a single I/O pin. The display is always on and the latch always displays what's in the counter, meaning that there may be some flicker visible on the display when updating the display by more than one. Also, the display cannot be forced to zero, so this configuration is best used for counting clock pulses rather than displaying arbitrary numbers.

Use the constructor:

myLED = TIL306(clk_pin, TIL306::NO_PIN, TIL306::NO_PIN, TIL306::NO_PIN);

Connect the pins as follows (pins not listed should be left floating):

By using four the control pins, all of the library functionality may be used (including intensity() if BI is connected to a PWM-capable pin).

Use the constructor:

myLED = TIL306(clk_pin, bi_pin, clr_pin, ls_pin);

Connect the pins as follows:

Recommended wiring to create a multiple-digit display (from The Optoelectronics Data Book for Design Engineers, Texas Instruments, Fifth Edition, p. 238):

Note that the above diagram has the least significant digit RBI (LED pin 6) connected to the second least significant digit RBO (LED pin 11). This will cause all digits to go blank when displaying zero across all digits. If you would like the value zero to be displayed with a zero in the least significant digit, then hardwire RBI HIGH on the least significant digit (and leave RBO floating on the second least significant digit).

• TIL306/307 datasheet
• The Optoelectronics Data Book for Design Engineers by Texas Instruments

The software and other files in this repository are released under what is commonly called the MIT License. See the file LICENSE.txt in this repository.