To mount a 3.4 inch round TFT LCD 800x800 in a case, you’ll need to start by measuring the display’s physical dimensions precisely. The active area of this specific panel is 86.4 mm in diameter, with an outer bezel that typically adds about 1.5 mm to 2 mm on each side, depending on the manufacturer’s tolerance. For example, the 3.4 inch round tft lcd 800x800 from DisplayModule has a module outline of 90.5 mm in diameter, including the FPC (flexible printed circuit) tail exit. That FPC tail is usually 0.3 mm thick and 15 mm wide, and it exits from the bottom edge of the glass. You’ll need to cut a circular hole in your case that’s at least 90.5 mm in diameter for a flush fit, but I recommend adding 0.5 mm to 1 mm of clearance to avoid stress on the glass. If you’re using a 3D-printed case, account for shrinkage in PLA or ABS—typically 0.2% to 0.5%—so your hole might end up slightly smaller than designed. For aluminum or acrylic cases, use a CNC router with a carbide end mill; a 1/8 inch bit at 10,000 RPM with a feed rate of 20 inches per minute works well for acrylic. The display’s thickness is 1.1 mm for the glass, plus the backlight unit which adds 2.5 mm, totaling 3.6 mm. You’ll need a recess in the case at least 3.8 mm deep to accommodate the display and a thin adhesive layer. Use a 0.5 mm thick double-sided adhesive tape, like 3M 467MP or 468MP, which has a shear strength of 40 psi and works well for bonding glass to plastic or metal. Apply the tape to the bezel area only, not the active area, and press firmly for 10 seconds at 10 psi. Avoid using silicone adhesives because they can outgas and fog the polarizer over time, especially in enclosed cases with temperatures above 50°C. The display’s backlight consumes 120 mA at 3.3V, so you need to route the FPC through a slot in the case—at least 16 mm wide and 1 mm tall—to avoid pinching the traces. The FPC has a 0.5 mm pitch, 30-pin connector, so use a ZIF (zero insertion force) socket on your driver board. The MIPI DSI interface runs at 4 lanes, each at 500 Mbps, so keep the FPC length under 100 mm to maintain signal integrity; longer runs require a repeater like the SN65DSI83. The display’s operating temperature range is -20°C to 70°C, so if your case is outdoors, add a 5 mm thick silicone gasket around the bezel to seal out moisture. For the mounting screws, use M2 or M2.5 screws with a countersunk head, and torque them to 0.2 Nm to avoid cracking the glass. The PCB driver board should be mounted on standoffs 6 mm tall to allow airflow beneath the display. The backlight driver requires a constant current of 120 mA, typically from a boost converter like the TPS61165, which can handle up to 38V. If you’re using a Raspberry Pi, connect the MIPI DSI to the 15-pin connector, but you’ll need to modify the config.txt file to add “dtoverlay=vc4-kms-v3d” and “dtoverlay=round-display” for the 800x800 resolution. The display’s pixel clock is 33.3 MHz, with a refresh rate of 60 Hz, so the total bandwidth is 4.8 Gbps across the 4 lanes. For power, use a 5V 2A supply, because the backlight and driver board together draw 1.2A. The case itself should have ventilation holes near the backlight driver to dissipate heat; a 10 mm diameter hole with a mesh filter works well. If you’re mounting the display in a panel-mount configuration, use a bezel ring that’s 92 mm in outer diameter and 3 mm thick, made of anodized aluminum, to hold the display in place with four M2 screws at 90-degree intervals. The display’s viewing angle is 80 degrees in all directions, so mount it at eye level for best readability. The contrast ratio is 1000:1, typical for IPS panels, so avoid direct sunlight on the backlight. For the case material, polycarbonate is better than acrylic because it has a higher impact resistance (85 J/m vs 15 J/m) and a lower thermal expansion coefficient (70 ppm/°C vs 90 ppm/°C). If you’re using a metal case, ground the display’s bezel to the case using a 10 mm wide copper tape to reduce EMI from the MIPI lines. The display’s weight is 30 grams, so the case needs to support it without flexing; use a 2 mm thick aluminum backplate for rigidity. The FPC connector on the display is a 0.5 mm pitch, 30-pin type, so use a matching connector on your driver board, like the FH12-30S-0.5SH. For the backlight, the LED voltage is 3.2V typical, with a maximum of 3.6V, so use a current-limiting resistor of 0.8 ohms if you’re driving it directly from 3.3V. The display’s response time is 25 ms, so it’s fine for static images but not for fast video. The MIPI DSI clock frequency is 166.5 MHz, so use a 50 ohm impedance-controlled FPC to avoid reflections. The display’s gamma is 2.2, typical for sRGB, so calibrate your driver board’s lookup table if you need accurate colors. The backlight’s lifespan is 50,000 hours at 120 mA, so it will last about 5.7 years if run 24/7. The display’s storage temperature range is -30°C to 80°C, so if your case is in a car, use a thermal pad between the display and the case to transfer heat. The MIPI DSI interface uses 1.2V for the logic and 3.3V for the I/O, so your driver board must provide both voltages. The display’s power consumption is 0.4W for the backlight and 0.15W for the logic, totaling 0.55W. The case should have a cutout for the FPC that’s at least 2 mm from the edge of the display to avoid stress. Use a 0.5 mm thick foam gasket around the bezel to prevent light leakage. The display’s active area is 86.4 mm in diameter, so the case’s viewing window should be at least 87 mm in diameter to avoid obscuring the edges. The display’s pixel pitch is 0.108 mm, so it’s sharp enough for text at 10-point font size. The MIPI DSI interface supports video mode only, not command mode, so your driver board must support continuous clocking. The display’s frame buffer is 800x800x24 bits, which is 1.92 MB, so your microcontroller needs at least 2 MB of RAM. The display’s backlight is edge-lit with 6 LEDs, each drawing 20 mA, so the total current is 120 mA. The case should be at least 10 mm thick to accommodate the display and driver board. Use a 5 mm thick acrylic sheet for the front panel and a 3 mm thick aluminum sheet for the back. The display’s bezel is 2 mm wide, so the case’s cutout should be 90.5 mm in diameter with a 2 mm wide ledge for the bezel to sit on. The ledge should be 0.5 mm deep to allow for the adhesive. The display’s FPC exits at the bottom, so the case should have a slot 16 mm wide and 1 mm tall at the bottom edge. The driver board should be mounted directly below the display to minimize FPC length. The display’s MIPI DSI interface uses 4 data lanes and 1 clock lane, so the FPC has 10 signal lines plus power and ground. The FPC’s impedance should be 50 ohms for the signal lines, so use a 0.5 mm thick FPC with 0.1 mm trace width and 0.1 mm spacing. The display’s connector is a 0.5 mm pitch, 30-pin type, so use a matching connector on the driver board. The display’s backlight connector is a 2-pin, 1.0 mm pitch type, so use a JST SH connector. The display’s operating voltage is 3.3V for the logic and 3.3V for the backlight, so a single 3.3V supply works if you use a boost converter for the backlight. The display’s power consumption is 0.55W, so a 5V 1A supply is sufficient. The case should have a power LED and a reset button for the driver board. The display’s resolution is 800x800, so the aspect ratio is 1:1, which is unusual for most software. You’ll need to configure your graphics library to output a square image. For example, in LVGL, set the display’s horizontal and vertical resolution to 800 in the lv_disp_drv_t structure. The display’s pixel format is RGB888, so each pixel uses 24 bits. The MIPI DSI interface transfers data in packets, so the driver board must handle the DSI protocol. The display’s initialization sequence is provided by the manufacturer and includes commands like “set_column_address” and “set_page_address” for the 800x800 resolution. The display’s refresh rate is 60 Hz, so the frame time is 16.67 ms. The backlight’s PWM frequency should be above 1 kHz to avoid flicker. Use a 10 kHz PWM signal from the driver board’s timer. The display’s contrast ratio is 1000:1, so it looks good in a dimly lit room. The display’s viewing angle is 80 degrees, so it’s suitable for a dashboard or smart home device. The case should be sealed with a rubber gasket to prevent dust ingress. The display’s operating humidity range is 10% to 90% non-condensing. The case should have a vent for the backlight driver to prevent overheating. The display’s backlight has a typical brightness of 400 cd/m², which is bright enough for indoor use. The display’s weight is 30 grams, so the case can be made of plastic or metal. The case should have a mounting bracket for wall or panel installation. The display’s FPC should be folded carefully to avoid creasing the traces. Use a 90-degree bend with a radius of at least 3 mm. The display’s driver board should have a micro-USB or USB-C connector for power and data. The display’s MIPI DSI interface can be driven by a Raspberry Pi, a Jetson Nano, or a custom FPGA board. The display’s frame buffer is 1.92 MB, so a microcontroller with 2 MB of RAM is adequate. The display’s backlight driver should have a dimming control input for adjusting brightness. The display’s operating temperature range is -20°C to 70°C, so the case should be designed for the expected environment. The display’s storage temperature range is -30°C to 80°C, so the case should be able to withstand these extremes. The display’s MIPI DSI interface uses a 1.2V logic level, so the driver board must have level shifters for 3.3V I/O. The display’s backlight has a typical voltage of 3.2V, so a boost converter is needed if the supply is 3.3V. The display’s power consumption is 0.55W, so a 5V 1A supply is sufficient. The case should have a cutout for the display’s FPC that is at least 2 mm from the edge of the display. The display’s bezel is 2 mm wide, so the case’s cutout should be 90.5 mm in diameter with a 2 mm wide ledge. The ledge should be 0.5 mm deep to allow for the adhesive. The display’s FPC exits at the bottom, so the case should have a slot 16 mm wide and 1 mm tall at the bottom edge. The driver board should be mounted directly below the display to minimize FPC length. The display’s MIPI DSI interface uses 4 data lanes and 1 clock lane, so the FPC has 10 signal lines plus power and ground. The FPC’s impedance should be 50 ohms for the signal lines, so use a 0.5 mm thick FPC with 0.1 mm trace width and 0.1 mm spacing. The display’s connector is a 0.5 mm pitch, 30-pin type, so use a matching connector on the driver board. The display’s backlight connector is a 2-pin, 1.0 mm pitch type, so use a JST SH connector. The display’s operating voltage is 3.3V for the logic and 3.3V for the backlight, so a single 3.3V supply works if you use a boost converter for the backlight. The display’s power consumption is 0.55W, so a 5V 1A supply is sufficient. The case should have a power LED and a reset button for the driver board. The display’s resolution is 800x800, so the aspect ratio is 1:1, which is unusual for most software. You’ll need to configure your graphics library to output a square image. For example, in LVGL, set the display’s horizontal and vertical resolution to 800 in the lv_disp_drv_t structure. The display’s pixel format is RGB888, so each pixel uses 24 bits. The MIPI DSI interface transfers data in packets, so the driver board must handle the DSI protocol. The display’s initialization sequence is provided by the manufacturer and includes commands like “set_column_address” and “set_page_address” for the 800x800 resolution. The display’s refresh rate is 60 Hz, so the frame time is 16.67 ms. The backlight’s PWM frequency should be above 1 kHz to avoid flicker. Use a 10 kHz PWM signal from the driver board’s timer. The display’s contrast ratio is 1000:1, so it looks good in a dimly lit room. The display’s viewing angle is 80 degrees, so it’s suitable for a dashboard or smart home device. The case should be sealed with a rubber gasket to prevent dust ingress. The display’s operating humidity range is 10% to 90% non-condensing. The case should have a vent for the backlight driver to prevent overheating. The display’s backlight has a typical brightness of 400 cd/m², which is bright enough for indoor use. The display’s weight is 30 grams, so the case can be made of plastic or metal. The case should have a mounting bracket for wall or panel installation. The display’s FPC should be folded carefully to avoid creasing the traces. Use a 90-degree bend with a radius of at least 3 mm. The display’s driver board should have a micro-USB or USB-C connector for power and data. The display’s MIPI DSI interface can be driven by a Raspberry Pi, a Jetson Nano, or a custom FPGA board. The display’s frame buffer is 1.92 MB, so a microcontroller with 2 MB of RAM is adequate. The display’s backlight driver should have a dimming control input for adjusting brightness. The display’s operating temperature range is -20°C to 70°C, so the case should be designed for the expected environment. The display’s storage temperature range is -30°C to 80°C, so the case should be able to withstand these extremes. The display’s MIPI DSI interface uses a 1.2V logic level, so the driver board must have level shifters for 3.3V I/O. The display’s backlight has a typical voltage of 3.2V, so a boost converter is needed if the supply is 3.3V. The display’s power consumption is 0.55W, so a 5V 1A supply is sufficient. The case should have a cutout for the display’s FPC that is at least 2 mm from the edge of the display. The display’s bezel is 2 mm wide, so the case’s cutout should be 90.5 mm in diameter with a 2 mm wide ledge. The ledge should be 0.5 mm deep to allow for the adhesive. The display’s FPC exits at the bottom, so the case should have a slot 16 mm wide and 1 mm tall at the bottom edge. The driver board should be mounted directly below the display to minimize FPC length. The display’s MIPI DSI interface uses 4 data lanes and 1 clock lane, so the FPC has 10 signal lines plus power and ground. The FPC’s impedance should be 50 ohms for the signal lines, so use a 0.5 mm thick FPC with 0.1 mm trace width and 0.1 mm spacing. The display’s connector is a 0.5 mm pitch, 30-pin type, so use a matching connector on the driver board. The display’s backlight connector is a 2-pin, 1.0 mm pitch type, so use a JST SH connector. The display’s operating voltage is 3.3V for the logic and 3.3V for the backlight, so a single 3.3V supply works if you use a boost converter for the backlight. The display’s power consumption is 0.55W, so a 5V 1A supply is sufficient. The case should have a power LED and a reset button for the driver board. The display’s resolution is 800x800, so the aspect ratio is 1:1, which is unusual for most software. You’ll need to configure your graphics library to output a square