PCA9622Matrix8x8 (pca9622matrix8x8 v0.1.3)

Driver for the switch-science "I2C 8x8 LED matrix" board (https://www.switch-science.com/products/2071), which multiplexes an 8x8 LED matrix over I2C using the PCA9622 constant-current LED driver.

start_link/1 accepts:

:bus_name - the I2C bus to open (default: "i2c-2")
:i2c_address - the PCA9622's I2C address (default: 0x50)
:reflesh_interval - column refresh interval in ms (default: 10)
:initial_matrix - initial 8x8 matrix to display
:name - GenServer name to register under (default: PCA9622Matrix8x8); pass nil to start unnamed, which allows multiple boards to run at once. When a name other than the default is used (or nil), pass the returned pid/name explicitly to set_matrix/2, set_matrix_bit/4 and stop/1.

Summary

Functions

all_off(ref, i2c_address \\ 80)

Turns every LED on the board fully off. Takes a raw I2C ref (from Circuits.I2C.open/1 or init_led/2), not a GenServer.

all_on(ref, i2c_address \\ 80)

Turns every LED on the board fully on. Takes a raw I2C ref (from Circuits.I2C.open/1 or init_led/2), not a GenServer. Useful as a quick hardware sanity check.

child_spec(init_arg)

Returns a specification to start this module under a supervisor.

set_matrix(server \\ __MODULE__, mat)

Replaces the whole 8x8 matrix that is currently displayed.

set_matrix_all(value)

Builds an 8x8 matrix (as used by set_matrix/2) with every pixel set to value. value may be 0/1, or any other term treated as falsy/truthy.

set_matrix_bit(server \\ __MODULE__, x, y, value)

Sets a single pixel (x, y) of the currently displayed matrix to value (0 or 1).

start_link(opts \\ [])

Starts the LED matrix driver GenServer. See the moduledoc for available opts.

stop(server \\ __MODULE__)

Stops the LED matrix driver GenServer, turning all LEDs off and closing the I2C bus.