• Designed for a high resolution 800x480 LCD
• Works with many 40-pin 4.3" LCDs

• 21-bit DPI 777 when using 40-pin Raspberry Pi boards
• 24-bit DPI 888 when using the Raspberry Pi CM4

Color depth refers to the number of bits used to represent the color of a single pixel.

• 21-bit DPI 777: Uses 7 bits for each color channel (red, green, blue), allowing for 128 shades per channel. This results in 2,097,152 possible colors.
• 24-bit DPI 888: Uses 8 bits for each color channel, allowing for 256 shades per channel. This results in 16,777,216 possible colors.

The CM4 supports a higher color depth, potentially providing smoother color gradients and more accurate color representation.

• 8 levels of adjustment available via display button
• Brightness level is stored when changed and recalled at bootup

Provides real-time feedback for:

• Brightness adjustments
• Battery status and charge levels
• Volume and mute controls

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• Graceful startup and shutdown with a momentary push switch
• More details in the Input section

• Supports 3.7v batteries with a JST PH 2.0mm connector
• Charge using the miniUSB or barrel jack (at up to 1.35 amps)
• The board works when no battery is installed, using only external power (you need a high amperage power source to run the CM4 in this manner)
• Efficient charging using a switching regulator with minimal heat generation
• Auto shutdown when the battery is depleted
• Auto forced power-off when the battery voltage drops below 3.08v

• Supports external USB power input for charging
• Provides output power to external USB devices

Note: The miniUSB port does not provide power to external devices unless the PSPi is powered on, with one exception. If the barrel jack is plugged in, the power from the barrel jack will pass through directly to the miniUSB port. This is useful when a USB device needs extra power.

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PWM audio signal processed through a low-noise buffer and filters for enhanced quality

• The low-noise buffer helps reduce unwanted electrical noise
• Filters smooth out the pulses into a continuous analog signal

This process helps achieve better audio quality from the digital output of the Raspberry Pi.

Automatic speaker muting upon headphone connection

Adjustable via buttons, with immediate feedback displayed on the OSD

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• Power Switch:
  • Power On: Sliding upward momentarily powers the PSPi on
  • Power Off: When on, another momentary press will shut the OS down and power the PSPi off
  • Forced Power Off: Holding it upward for 3-5 seconds will force the PSPi to power off
  • Sleep: Placing it into the Hold position will activate a locked sleep mode, disabling audio, input, and the LCD
• Left Switch: Enables and disables the battery indicator (programmable)
• Display Button:
  • Pressing cycles through 8 brightness levels
  • The brightness level is stored when changed and recalled at bootup
• Mute Button:
  • Press to mute speakers, headphones, and disable audio electronics
  • Press again to re-enable and unmute audio
  • The mute status is stored when changed and recalled at bootup
• Volume Buttons:
  • Press or hold Vol - or + to adjust volume

• SD/eMMC activity indicator above the left switch
• WiFi connection status indicator below the left switch (programmable)
  • LED turns on when WiFi is connected
• Power status indicated by the right LED
  • Green for normal status
  • Orange for charging or low battery
  • Pulsing when the power switch is in the Hold position

Maintains time and date when powered off

Atmega8a performs several crucial functions:

1. Power Management:

   • Monitors battery voltage and manages power states
   • Handles graceful startup and shutdown sequences
   • Controls sleep mode to reduce power consumption

2. Input Processing:

   • Reads and debounces button inputs
   • Manages analog inputs for joysticks
   • Handles special button combinations (e.g., for brightness control)

3. Display Control:

   • Manages LCD backlight brightness levels
   • Initializes and controls the LCD display

4. Audio Control:

   • Manages audio mute functionality
   • Controls power to audio components

5. I2C Communication:

   • Acts as an I2C slave device to communicate with the Raspberry Pi
   • Sends input states and receives commands from the Raspberry Pi

6. LED Management:

   • Controls status LEDs for various indicators (e.g., battery status, WiFi)

By handling these tasks, the Atmega8a reduces the workload on the Raspberry Pi, freeing up those resources for other uses.

• Additional inputs for 2 analog axes (single joystick) and two buttons
• I2C: Pads for SDA and SCL, enabling use of additional I2C devices
• Touch: Connections for touch panel (details to be provided later)

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• Reduces power consumption while in "standby"
• ATmega microcontroller turns off screen and cuts power to audio circuits
• Controls are locked to prevent accidental inputs
• Raspberry Pi detects sleep mode, pauses drivers, switches CPU governor to powersave mode
• If RetroArch is running, it will be paused to save resources
• Can disable WiFi if configured to do so

Reduces power usage by disabling audio circuits

Design optimized for minimal power consumption, using as many of the Raspberry Pi's integrated features as possible

All functionalities are programmed in C for optimal performance