Arduino library for 7-segment LCDs based on the HT1621 driver, with support for 4-digit displays and various low power modes. Often marked as PDC-6X1 (6-digits) or LCM0220 (4-digits).
Based on the bitbanging efforts by anxzhu (2016-2018).
APIs rewritten in 2018 to follow the LiquidCrystal format by valerionew.
Rewritten again by kreddkrikk with support for 4-digit displays and low power modes.
-
void begin(int width, int cs_p, int wr_p, int data_p)Activate the display. Acceptable values for width are 6 for 6-digit displays and 4 for 4-digit displays. -
void begin(int width, int cs_p, int wr_p, int data_p, int backlight_p)Activate the display with backlight control. -
void powerDown()Power down the display. This reduces power consumption to <0.1uA. -
void powerUp()Bring the display out of power down status. -
void standBy()Turn off MCU pins, but keep the display active. This reduces power consumption by about 100uA. The display cannot be updated while in standby mode until active() is called. -
void active()Come out of standby mode to update the display. -
void clear()Clear the display. -
void lcdOn()Turn the display on. -
void lcdOff()Turn the display off. -
void backlightOn()Turn on the backlight. -
void backlightOff()Turn off the backlight. -
void print(const char* str)Base function for all other print functions. -
void print(double num, int precision)Print floating value, right-aligned. -
void print(int num)Print 16-bit integer, right-aligned. -
void print(long num)Print 32-bit integer, right-aligned. -
void printTemp(double num, char unit, bool degree)Print the temperature, optionally including degree symbol and unit. Setunitto NULL to hide the unit symbol. -
void printTime(bool pad, int num1, int num2)Print clock/timer number pair separated by colon or decimal, with the first number optionally padded by leading zeros. -
void printError(int err)Print an error code to the display. -
void batteryLevel(int level)Set the battery indicator.
Current draw for an active display can be reduced to ~100uA using standby mode and running the display from a 3.3V power source. If operating the display from a microcontroller running at <10uA, two AAA batteries (3.0V, 2400mAh) would theoretically power such a setup for ~2.5 years.