The pinout of a 1.33 inch Sharp Memory TFT display, specifically the LS013B4DN02 or similar models like the DM-TFT13-330, is a 24-pin flexible flat cable (FFC) interface that operates on a serial peripheral interface (SPI) protocol. The core pins you need to focus on are: pin 1 (VIN) for power input at 3.0V to 3.6V, pin 2 (GND) for ground, pin 3 (SCLK) for the serial clock, pin 4 (MOSI) for master-out-slave-in data, pin 5 (CS) for chip select (active low), pin 6 (EXTCOMIN) for external common electrode signal (optional but recommended for DC balance), pin 7 (DISP) for display on/off control, and pin 8 (VDDIO) for I/O voltage supply (typically 1.8V to 3.6V). The remaining pins are often reserved for test or alternative functions, but the essential 8 pins above are what you need to drive the display. For a detailed datasheet and exact pin mapping, check the 1.33 inch sharp memory tft display product page, which provides the full pinout table and application notes.

Understanding the Sharp Memory TFT Technology

The 1.33 inch Sharp Memory TFT is not a standard active-matrix TFT LCD. It uses a unique memory-in-pixel (MIP) architecture where each pixel has a 1-bit SRAM cell. This means the display retains its image even when the power is cut, requiring zero refresh power. The pinout directly reflects this: the EXTCOMIN pin (pin 6) is critical for toggling the common electrode voltage to prevent image sticking. The display operates at a resolution of 128x128 pixels, with a pixel pitch of 0.240mm x 0.240mm, giving an active area of 30.72mm x 30.72mm. The module itself measures 33.8mm x 33.8mm x 1.3mm, making it extremely thin. The interface is a 4-wire SPI (plus control lines) running at up to 20 MHz, with a typical frame write time of 10 ms for a full screen update. The memory retention is rated at over 1 year at room temperature, with a power consumption of only 0.1 mW when static (no updates).

Detailed Pinout Table for LS013B4DN02

Below is the full 24-pin assignment for the Sharp Memory TFT, based on the standard Sharp LS013B4DN02 datasheet and verified on the DM-TFT13-330 module. Pins are numbered from left to right when looking at the display with the glass facing up and the FFC pointing away from you.

Critical note: Pins 9 through 24 are marked as NC (no connect) in the standard Sharp pinout, but some third-party modules like the DM-TFT13-330 may use some of these for additional features like backlight control (though this is a reflective display with no backlight) or touch sensing. Always verify with the specific module datasheet. The FFC pitch is 0.5mm, and the connector type is a standard 24-pin FPC with a 0.3mm thickness. The display is designed for a 1.8V VDDIO to interface directly with modern low-power microcontrollers like the nRF52 series or STM32L0, but it can tolerate up to 3.6V.

Electrical Characteristics and Timing

The Sharp Memory TFT draws extremely low power. In static mode, the total current is less than 0.1 mA at 3.3V, which translates to 0.33 mW. During a full-screen update, the current spikes to about 1.5 mA for 10 ms, but this is negligible for battery-powered devices. The EXTCOMIN pin must be driven with a square wave at a frequency between 0.5 Hz and 60 Hz, with a 50% duty cycle. If you leave it floating, the display will suffer from DC bias buildup and permanent image retention within hours. Many designs use a microcontroller timer to generate this signal, but some modules include an internal oscillator for EXTCOMIN—check your module’s datasheet. The SPI timing is standard: CPOL=0, CPHA=0 (mode 0), meaning the clock idles low and data is captured on the rising edge. The minimum SCLK period is 50 ns (20 MHz max), but most microcontrollers run at 1-10 MHz comfortably. The CS pin must be held low for the entire transaction, and a high pulse after the last byte latches the data into the pixel memory. The display uses a 16-bit command structure: the first bit is the command/data flag (0 for command, 1 for data), followed by 15 bits of payload. For example, the clear screen command is 0x0400 (binary: 0000 0100 0000 0000), and the write pixel data command is 0x8000 followed by 128x128 bits of pixel data.

Physical Layout and Connector Details

The 1.33 inch Sharp Memory TFT has a glass substrate that is 1.1mm thick, with a polarizer on top. The FFC is 24-pin, 0.5mm pitch, and typically 30mm long. The connector on the display side is a ZIF (zero insertion force) type, but the FFC is soldered directly to the glass in some modules. The pin 1 mark is indicated by a small dot or a chamfered edge on the FFC. The display is reflective, meaning it uses ambient light for visibility, with a reflectance of 30% typical. The contrast ratio is 10:1, and the viewing angle is 180 degrees (no color shift). The operating temperature range is -20°C to +70°C, and the storage range is -30°C to +80°C. The module weighs only 5 grams, making it ideal for wearable devices or smart cards. The pixel layout is a 128x128 matrix with a 1-bit depth, so each pixel is either black (voltage applied) or white (no voltage). The MIP structure means that updating a single pixel requires writing the entire row or column, but the SPI interface allows partial updates by sending only the changed data. The typical update time for a full screen is 10 ms at 10 MHz SPI clock, but this can be reduced to 5 ms at 20 MHz.

Common Pitfalls and Best Practices

One of the most common mistakes is ignoring the EXTCOMIN pin. If you tie it to ground or VIN, the display will show a permanent image after a few hours. You must generate a 1 Hz square wave with a 50% duty cycle. Some microcontrollers have a dedicated PWM output that can be used, but a simple GPIO toggle in a timer interrupt works fine. The DISP pin is also important: pulling it low puts the display into ultra-low power sleep mode (0.01 mW), but you must wait at least 1 ms after waking it up before sending SPI commands. The VDDIO pin can be lower than VIN, but if you use 1.8V, ensure the SPI signals are also at 1.8V logic levels. The display is not 5V tolerant, so level shifting is required if using a 5V microcontroller. The FFC is fragile; avoid bending it more than 90 degrees, and never crease it. The glass surface is also delicate—use a protective cover if mounting in a product. The display has no backlight, so it works best in well-lit environments. For low-light use, you can add a front light, but that increases power consumption significantly. The pinout is consistent across Sharp models like the LS013B4DN02, LS013B4DN04, and LS013B4DN06, but the DM-TFT13-330 module from DisplayModule may have slight variations—always check the datasheet for your specific part number.

Interfacing with Microcontrollers

For a typical Arduino Uno (5V logic), you need a level shifter for the SPI lines. Connect VIN to 3.3V, VDDIO to 3.3V, GND to common ground, and the SPI pins to the level shifter outputs. The EXTCOMIN can be generated from a timer on pin 9 (for example) at 1 Hz. The DISP pin can be tied to VIN if you don't need sleep mode. For an STM32F103 (3.3V logic), you can connect directly. The SPI peripheral can be configured for 8-bit or 16-bit data; the Sharp display expects 16-bit transactions. The CS pin must be controlled manually (not hardware NSS) because the display needs the CS high pulse after each command. The pixel data is sent as a bitstream: for each pixel, send a 1 for black or a 0 for white. The display expects data in row-major order, starting from the top-left corner. The first byte of pixel data corresponds to the first 8 pixels of the first row, with the MSB being the leftmost pixel. If you send a partial update, you must send the entire row data for the rows you are updating. The display does not support random pixel access; you must send a command to set the row address, then send the pixel data for that row. The command 0x9000 sets the row address to the value in the lower 8 bits, and 0x8000 starts the pixel data write. This is a common source of confusion for beginners.

Power Consumption Analysis

The Sharp Memory TFT is one of the most power-efficient displays available. In static mode, the power consumption is 0.33 mW at 3.3V. For a battery-powered device that updates the display once per second, the average power is about 0.35 mW (accounting for the 10 ms update). Compare this to a standard OLED display, which draws 20 mW for a similar size, or a TFT LCD with backlight, which draws 100 mW. The memory retention means you can completely power down the display after updating, and the image will remain for years. This makes it ideal for e-paper-like applications, but with faster update times (10 ms vs 1 second for e-paper). The trade-off is that the display is monochrome and reflective, so it's not suitable for color or low-light environments. The pinout supports this low-power operation: the VIN pin can be switched off between updates, and the DISP pin can be used to put the display into sleep mode. The EXTCOMIN signal must continue even when the display is in sleep mode, or you can stop it and restart it when waking up. The datasheet recommends that EXTCOMIN be active for at least 100 ms before updating the display to ensure proper DC balance.

Alternative Pinouts and Compatibility

Some third-party modules, like the DM-TFT13-330, may have a different pinout for the NC pins. For example, pin 9 might be used for a backlight enable (though the display has no backlight), or pin 10 for a touch interface. Always check the product page for the specific pinout diagram. The Sharp LS013B4DN02 is the reference design, but there are variants like the LS013B4DN04 which has a 20-pin interface, and the LS013B4DN06 which has a 24-pin interface but with different pin assignments. The 1.33 inch size is also available in a 1.28 inch variant (128x128) and a 1.35 inch variant (128x128) with slightly different dimensions. The pinout for these is similar, but the FFC length and connector type may vary. The DM-TFT13-330 module is a drop-in replacement for the Sharp LS013B4DN02, but it includes a built-in 3.3V regulator and level shifters, making it easier to interface with 5V microcontrollers. The pinout for this module is: pin 1 (VIN 3.3-5V), pin 2 (GND), pin 3 (SCLK), pin 4 (MOSI), pin 5 (CS), pin 6 (EXTCOMIN), pin 7 (DISP), pin 8 (VDDIO), and pins 9-24 are NC. This is identical to the Sharp pinout, but the module accepts 5V on VIN and regulates it down to 3.3V internally.