`lcd` — lcd driver¶

The lcd module is used for driving SPI LCDs, 24-bit parallel LCDs, MIPI DSI LCDs, HDMI output, and Display Port output.

Example usage for driving the 128x160 LCD shield:

import sensor, lcd

# Setup camera.
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.LCD)
sensor.skip_frames()
lcd.init()

# Show image.
while(True):
    lcd.display(sensor.snapshot())

Functions¶

lcd.init([type=lcd.LCD_SHIELD[, width=128[, height=160[, framesize=lcd.FWVGA[, refresh=60[, triple_buffer=False[, bgr=False[, byte_reverse=False]]]]]]]])¶

Initializes an attached lcd module.

type indicates how the lcd module should be initialized:

lcd.LCD_NONE: Do nothing.

lcd.LCD_SHIELD: Initialize a SPI LCD display. Uses pins P0, P2, P3, P6, P7, and P8.

lcd.LCD_DISPLAY: Initialize the LCD module driving a high resolution display.

lcd.LCD_DISPLAY_WITH_HDMI: Initialize dirivng a high res display and HDMI output too.

lcd.LCD_DISPLAY_ONLY_HDMI: Initialize only driving the HDMI output.

width SPI LCD width in lcd.LCD_SHIELD mode. By default this is 128 to match the OpenMV 128x160 LCD shield.

height SPI LCD height in lcd.LCD_SHIELD mode. By default this is 160 to match the OpenMV 128x160 LCD shield.

framesize One of the standard supported resolutions in LCD_DISPLAY* modes.

refresh Sets the LCD refresh rate in hertz. In particular, this controls the SPI LCD shield clock and high resolution display clock. If you are experiencing bandwidth issues driving the external display you may lower this to lower the memory bandwidth requirements. Alternatively, you can raise this if all system components allow for faster screen updates.

triple_buffer If True then makes updates to the screen non-blocking in lcd.LCD_SHIELD mode at the cost of 3X the display RAM. In LCD_DISPLAY* modes triple_buffer is always on.

bgr set to True in lcd.LCD_SHIELD to swap the red and blue channels. This argument allows you to use our driver with more types of displays.

byte_reverse set to True in lcd.LCD_SHIELD to swap RGB565 pixel bytes sent to the LCD. This argument allows you to use our driver with more types of displays.

lcd.deinit()¶: Deinitializes the lcd module, internal/external hardware, and I/O pins.

lcd.width()¶: Returns the width of the screen that was set during lcd.init().

lcd.height()¶: Returns the height of the screen that was set during lcd.init().

lcd.type()¶: Returns the type of the screen that was set during lcd.init().

lcd.triple_buffer()¶: Returns if triple buffering is enabled that was set during lcd.init().

lcd.bgr()¶: Returns if the red and blue channels are swapped that was set during lcd.init().

lcd.byte_reverse()¶: Returns if the RGB565 pixels are displayed byte reversed that was set during lcd.init().

lcd.framesize()¶: Returns the framesize that was set during lcd.init().

lcd.refresh()¶: Returns the refresh rate that was set during lcd.init().

lcd.set_backlight(value)¶

Sets the lcd backlight dimming value. 0 (off) to 255 (on).

In lcd.LCD_SHIELD mode this controls the DAC on P6 to provide the dimming value. If set to 0 P6 is pulled low and if set to 255 P6 is unitialized assuming that the SPI LCD shield’s backlight is by default always on.

In LCD_DISPLAY* modes this controls a PWM signal to a standard backlight dimming circuit.

lcd.get_backlight()¶: Returns the lcd backlight dimming value.

lcd.get_display_connected()¶

In LCD_DISPLAY_*_HDMI modes returns if an external display is connected.

This function can be called before lcd.init() so you can control how you init this module.

lcd.register_hotplug_cb(callback)¶

In LCD_DISPLAY_*_HDMI modes registers a callback function that be called whenever the state of an external display being connected changes. The new state will be passed as an argument.

If you use this method do not call lcd.get_display_connected() anymore until the callback is disabled by pass None as the callback for this method.

lcd.get_display_id_data()¶

In LCD_DISPLAY_*_HDMI modes this function returns the external display EDID data as a bytes() object. Verifying the EDID headers, checksums, and concatenating all sections into one bytes() object is done for you. You may then parse this information by following this guide.

This function can be called before lcd.init() so you can control how you init this module.

lcd.send_frame(dst_addr, src_addr, bytes)¶: In LCD_DISPLAY_*_HDMI modes this function sends a packet on the HDMI-CEC bus to dst_addr with source src_addr and data bytes.

lcd.receive_frame(dst_addr, timeout=1000)¶: In LCD_DISPLAY_*_HDMI modes this function waits timeout milliseconds to receive an HDMI-CEC frame for address dst_addr. Returns True if the received frame was for dst_addr and False if not. On timeout throws an OSError Exception.

lcd.register_receive_cb(callback, dst_addr)¶

In LCD_DISPLAY_*_HDMI modes registers a callback which will be called on reception of an HDMI-CEC frame. The callback will receive one argument of True or False if the HDMI-CEC frame was for dst_addr or not.

If you use this method do not call lcd.receive_frame() anymore until the callback is disabled by pass None as the callback for this method.

lcd.received_frame_src_addr()¶

In LCD_DISPLAY_*_HDMI modes returns the received HDMI-CEC frame source address if lcd.receive_frame() or the callback in lcd.register_receive_cb() returned True.

When a callback is enabled for the HDMI-CEC bus this method should not be called anymore except inside of the callback.

lcd.received_frame_bytes()¶

In LCD_DISPLAY_*_HDMI modes returns the received HDMI-CEC frame data payload as a bytes object if lcd.receive_frame() or the callback in lcd.register_receive_cb() returned True.

When a callback is enabled for the HDMI-CEC bus this method should not be called anymore except inside of the callback.

lcd.update_touch_points()¶: In LCD_DISPLAY* modes this function reads the touch screen state and returns the number of touch points (0-5).

lcd.register_touch_cb(callback)¶

In LCD_DISPLAY* modes this function registers a callback which will receive the number of touch points (0-5) when a touch event happens.

If you use this method do not call lcd.update_touch_points() anymore until the callback is disabled by pass None as the callback for this method.

lcd.get_gesture()¶

In LCD_DISPLAY* modes this returns the current touch gesture.

This is one of LCD_GESTURE_*.