Welcome¶

This documentation will guide you through the methods available in the Four Letter pHAT python library.

Four Letter pHAT is a Raspberry Pi add-on with four star displays.

• More information - https://shop.pimoroni.com/products/four-letter-phat
• GPIO Pinout - http://pinout.xyz/pinout/four_letter_phat
• Get the code - https://github.com/pimoroni/four-letter-phat
• Get help - http://forums.pimoroni.com/c/support

At A Glance¶

Alphanumeric 14 segment LED backpack display.

fourletterphat.begin()¶

fourletterphat.clear()¶

fourletterphat.glow(period=4, duration=4)¶

fourletterphat.print_float(value, decimal_digits=2, justify_right=True)¶

fourletterphat.print_hex(value, justify_right=True)¶

fourletterphat.print_number_str(value, justify_right=True)¶

fourletterphat.print_str(value, justify_right=True)¶

fourletterphat.scroll_print(s, tempo=0.3)¶

fourletterphat.set_blink(frequency)¶

fourletterphat.set_brightness(brightness)¶

fourletterphat.set_decimal(pos, decimal)¶

fourletterphat.set_digit(pos, digit, decimal=False)¶

fourletterphat.set_digit_raw(pos, bitmask)¶

fourletterphat.set_led(led, value)¶

fourletterphat.show()¶

fourletterphat.write_display()¶

Set A Single Digit¶

fourletterphat.set_digit(pos, digit, decimal=False)

Set digit at position to provided value.

Position should be a value of 0 to 3 with 0 being the left most digit on the display. Digit should be any ASCII value 32-127 (printable ASCII).

fourletterphat.set_digit_raw(pos, bitmask)

Set digit at position to raw bitmask value.

Position should be a value of 0 to 3 with 0 being the left most digit on the display.

Set A Decimal Point¶

fourletterphat.set_decimal(pos, decimal)

Turn decimal point on or off at provided position.

Position should be a value 0 to 3 with 0 being the left most digit on the display. Decimal should be True to turn on the decimal point and False to turn it off.

Print A Float¶

fourletterphat.print_float(value, decimal_digits=2, justify_right=True)

Print a numeric value to the display.

If value is negative it will be printed with a leading minus sign. Decimal digits is the desired number of digits after the decimal point.

Print Hexadecimal¶

fourletterphat.print_hex(value, justify_right=True)

Print a numeric value in hexadecimal.

Value should be from 0 to FFFF.

Print A String¶

fourletterphat.print_str(value, justify_right=True)

Print a 4 character long string of values to the display.

Characters in the string should be any ASCII value 32 to 127 (printable ASCII).

Print A Number String¶

fourletterphat.print_number_str(value, justify_right=True)

Print a 4 character long string of numeric values to the display.

This function is similar to print_str but will interpret periods not as characters but as decimal points associated with the previous character.

Blink The Display¶

fourletterphat.set_blink(frequency)

Blink display at specified frequency.

Note that frequency must be a value allowed by the HT16K33, specifically one of:

• HT16K33_BLINK_OFF,
• HT16K33_BLINK_2HZ,
• HT16K33_BLINK_1HZ, or
• HT16K33_BLINK_HALFHZ.

Set Brightness¶

fourletterphat.set_brightness(brightness)

Set brightness of entire display to specified value.

Supports 16 levels, from 0 to 15.

Clear The Display¶

fourletterphat.clear()

Clear contents of display buffer.

Update The Display¶

Once you’ve made your changes, you’ll need to update the display.

fourletterphat.show()

Display buffer on display.