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DSI Display (7" Official Raspberry Pi Panel)

Time estimate: ~30 minutes Prerequisites: SSH Login, Framebuffer Basics, DRM/KMS Test Pattern

Learning Objectives

By the end of this tutorial you will be able to:

  • Connect and configure the official 7" DSI display on a Raspberry Pi
  • Explain why DSI panels work out of the box and what makes this different from SPI displays
  • Verify the DSI connector in DRM/KMS and run test patterns on it
  • Use SDL2 and Qt EGLFS applications on DSI without modification
  • Configure dual-display output (DSI + HDMI simultaneously)
  • Compare SPI, DSI, and HDMI display interfaces with measurements
DSI: GPU-Accelerated Display via Ribbon Cable

MIPI DSI (Display Serial Interface) connects flat panels to the SoC's GPU display controller through dedicated high-speed differential lanes — the same scan-out path used by HDMI. The GPU renders into a DRM buffer and the display controller clocks pixels out over DSI lanes during VBlank, with no CPU involvement per frame. This contrasts with SPI displays, where the CPU must transfer every pixel through the SPI bus. Because DSI shares the DRM/KMS pipeline with HDMI, existing SDL2, Qt EGLFS, and custom DRM applications work on DSI panels without code changes. The physical differences are the connector (ribbon cable vs HDMI plug) and the touch controller (I2C capacitive vs none).

See also: Graphics Stack reference | Camera and Display Interfaces for D-PHY signaling, DSI packet structure, and bandwidth math

Introduction

MIPI DSI (Display Serial Interface) is the standard connection for flat panels in phones, tablets, and embedded products. Unlike SPI displays that push pixels through a slow serial bus with CPU involvement, DSI panels connect to the GPU's display controller through dedicated high-speed differential lanes. The GPU scans pixels out of a DRM buffer directly to the panel — the same path used for HDMI.

This means your existing DRM/KMS applications, SDL2 programs, and Qt EGLFS dashboards work on a DSI display without code changes. The only differences are physical: a ribbon cable instead of an HDMI connector, and an I2C capacitive touch controller instead of no touch.

This tutorial uses the official Raspberry Pi 7" 800×480 DSI display with its FT5x06 capacitive touch controller. The same steps apply to compatible third-party 5" and 7" DSI panels.

1. Physical Connection

Concept: DSI uses a flat ribbon cable connecting the Pi's dedicated DSI port to the panel's driver board. This is a direct GPU-to-panel link — no SPI, no GPIO.

Warning

DSI ribbon cables are fragile. Handle by the edges, not the contacts. The connector on the Pi has a locking tab — lift the tab, insert the cable with contacts facing the correct direction (usually toward the board), then press the tab down to lock.

Connection Steps

  1. Power off the Pi completely
  2. Locate the DSI connector on the Pi (labeled "DISPLAY", between the HDMI ports and the GPIO header)
  3. Lift the connector's locking tab gently
  4. Insert the ribbon cable — contacts face toward the Pi board (away from the tab)
  5. Press the locking tab down firmly
  6. Connect the other end to the display's driver board (same technique)
  7. Connect the display's power cable to the Pi's GPIO 5V and GND pins (or USB, depending on the panel)
Checkpoint

The ribbon cable is seated in both connectors with locking tabs closed. Power cables are connected.

2. Why It Works Out of the Box

Concept: On a fresh Raspberry Pi OS install, the official 7" DSI display requires zero configuration. The firmware detects the panel, enables it, and the kernel's DRM driver binds it automatically.

Power on the Pi with the DSI panel connected and SSH in.

Verify Detection

dmesg | grep -i dsi

You will see output like this:

[    0.025027] /soc/cprman@7e101000: Fixed dependency cycle(s) with /soc/dsi@7e700000
[    0.025164] /soc/dsi@7e700000: Fixed dependency cycle(s) with /soc/dsi@7e700000/bridge@0
[    5.854992] vc4-drm gpu: bound fe700000.dsi (ops vc4_dsi_ops [vc4])

The "Fixed dependency cycle" messages are harmless — the kernel's driver core is resolving circular references between the DSI controller, its bridge chip, and the clock manager. The important line is the last one: bound fe700000.dsi confirms the vc4 DRM driver has claimed the DSI hardware.

Check the DRM connector status:

cat /sys/class/drm/card0-DSI-1/status

connected
Why No Configuration Was Needed

Three things make this work without touching config.txt:

  1. display_auto_detect=1 — This firmware setting (enabled by default) tells the VideoCore bootloader to probe the I2C bus for known display controllers before Linux boots. The official 7" display has an ATTINY88 microcontroller on its driver board that responds to this probe.

  2. panel_disp@1 in the base device tree — The Pi's device tree already includes a panel node for the DSI display. You can inspect it:

    cat /proc/device-tree/panel_disp@1/compatible
# raspberrypi,7inch-dsi

    This node describes the panel's resolution (800×480), timing, and the TC358762 DSI-to-DPI bridge chip that sits between the SoC's DSI controller and the panel's LCD driver.

  3. The vc4 DRM driver binds the DSI controller at fe700000.dsi, discovers the bridge and panel nodes, and creates a card0-DSI-1 connector — the same DRM/KMS path used for HDMI.

The hardware chain on the official display:

SoC DSI controller (fe700000.dsi)
    → TC358762 bridge chip (DSI-to-DPI conversion)
        → LCD panel (800×480, 60 Hz)
FT5x06 touch controller ← I2C (address 0x38)
    → /dev/input/eventN

The DSI ribbon cable carries both the high-speed display lanes and the I2C signals for touch — one cable for everything.

For custom images: Enable CONFIG_DRM_PANEL_RASPBERRYPI_TOUCHSCREEN and CONFIG_DRM_VC4 in your kernel config. The device tree must include the panel_disp@1 node (copy it from the Pi's upstream .dts) or load the vc4-kms-dsi-7inch overlay.

Manual Overlay (Third-Party Panels)

If you have a non-official DSI panel that is not auto-detected, add the overlay manually:

sudo nano /boot/firmware/config.txt

Add the appropriate overlay:

dtoverlay=vc4-kms-dsi-7inch
Stuck?

The overlay name varies by panel. Common options:

  • vc4-kms-dsi-7inch — official Raspberry Pi 7" and many compatible 5"/7" panels
  • vc4-kms-dsi-waveshare-panel — some Waveshare DSI panels

Check what's available: 

ls /boot/firmware/overlays/*dsi*.dtbo

Reboot if you changed config.txt:

sudo reboot
Checkpoint

cat /sys/class/drm/card0-DSI-1/status shows connected. The display has its backlight on (showing a console or blank screen on Lite).

3. Verify with DRM/KMS

Concept: DSI appears as a DRM connector alongside HDMI. Both use the same GPU-accelerated DRM/KMS path — you choose the output by selecting the connector.

Install DRM Tools

modetest is not installed by default on Lite:

sudo apt install -y libdrm-tests

List Connectors

sudo modetest -M vc4 -c

You should see two connectors listed:

  • HDMI-A-1 (or HDMI-A-2) — status: connected or disconnected
  • DSI-1 — status: connected

Note the connector ID for DSI-1 (e.g., id: 2).

Run Test Pattern on DSI

The vc4 driver uses atomic modesetting — you must pass -a to modetest. The syntax is -s <CONNECTOR_ID>@<CRTC_ID>:<MODE>:

# Find your connector and CRTC IDs from the listing above
# Example: connector=47, crtc=46, mode=800x480
sudo modetest -M vc4 -a -s 47@46:800x480

Replace 47 and 46 with the connector and CRTC IDs from your modetest -c output. A test pattern should appear on the DSI display.

Why -a (Atomic Modesetting)?

The vc4 DRM driver on modern Raspberry Pi OS uses atomic modesetting exclusively. Without -a, modetest tries the legacy modesetting path and fails with "failed to find CRTC for pipe" — the CRTC is managed atomically and the legacy interface cannot claim it.

Atomic modesetting applies all display changes (connector, CRTC, plane, mode) in a single commit — either everything succeeds or nothing changes. This prevents partial updates that could leave the display in a broken state.

Checkpoint

A test pattern appears on the DSI display. This confirms the GPU scan-out path is working.

Stuck?
  • "failed to find CRTC for pipe" — you forgot -a, or fbcon still holds the CRTC. Unbind it first: echo 0 | sudo tee /sys/class/vtconsole/vtcon1/bind
  • "failed to find mode" — check the exact mode name from modetest -c. The DSI panel reports 800x480 (no -60 suffix)
  • Only HDMI listed — the DSI panel was not detected; check cable and overlay

4. Quick Visual Test with Python

Concept: The DSI display also appears as /dev/fb0 — writing pixels to this file makes them appear on screen, just like with SPI displays. The fbdev compatibility layer exposes the DSI framebuffer as RGB565 (16 bpp) by default — the same pixel format as SPI displays, so the same PIL pixel-packing code works on both.

Framebuffer Pixel Format: fbdev vs DRM

The /dev/fb0 legacy framebuffer interface defaults to 16 bpp (RGB565) on the Pi's DSI output. This is the fbdev compatibility layer — a simplified interface over the real DRM/KMS driver. Applications using the full DRM/KMS path (SDL2, Qt EGLFS) work with XRGB8888 (32 bpp) and get GPU-accelerated rendering, VSync, and page flipping.

For Python PIL scripts that write directly to /dev/fb0, RGB565 is fine and keeps the code identical to the SPI display scripts. The important difference from SPI is not the pixel format but the scan-out path — the GPU reads this buffer via DMA at 60 Hz, while SPI requires the CPU to push every pixel over the bus.

Install Dependencies

sudo apt-get install -y python3-pil python3-evdev fonts-dejavu-core

Draw a Test Pattern

This script auto-detects the framebuffer's pixel format and draws a status UI:

cat > dsi_draw.py << 'EOF'
#!/usr/bin/env python3
"""Draw a test pattern on the DSI display framebuffer.

Auto-detects pixel format (RGB565 or XRGB8888) from sysfs.
"""
import struct, os, sys

# ── Framebuffer setup ────────────────────────────────────
fb_dev = "/dev/fb0"
fb_id = os.path.basename(fb_dev)
def read_sysfs(attr):
    with open(f"/sys/class/graphics/{fb_id}/{attr}") as f:
        return f.read().strip()

width, height = [int(x) for x in read_sysfs("virtual_size").split(",")]
bpp = int(read_sysfs("bits_per_pixel"))
stride = int(read_sysfs("stride"))
Bpp = bpp // 8   # bytes per pixel
fmt = "RGB565" if bpp == 16 else "XRGB8888"
print(f"Resolution: {width}x{height}, {bpp} bpp ({fmt}), stride={stride}")

# ── Draw with PIL ────────────────────────────────────────
from PIL import Image, ImageDraw, ImageFont

img = Image.new("RGB", (width, height), (0, 0, 0))
draw = ImageDraw.Draw(img)

try:
    font = ImageFont.load_default(size=24)
    font_sm = ImageFont.load_default(size=18)
except TypeError:
    font = ImageFont.load_default()
    font_sm = font

draw.rectangle([10, 10, width-10, height-10], outline=(0, 200, 255), width=2)
draw.text((30, 30), "DSI DISPLAY", fill=(200, 200, 220), font=font)
draw.text((30, 70), f"Resolution: {width}x{height}", fill=(100, 180, 120), font=font_sm)
draw.text((30, 100), f"Format: {fmt} ({bpp} bpp)", fill=(100, 180, 120), font=font_sm)
draw.text((30, 130), f"Frame: {stride * height:,} bytes", fill=(100, 180, 120), font=font_sm)
draw.text((30, 170), "GPU scan-out (DRM/KMS)", fill=(180, 140, 80), font=font_sm)

# Color bars
bar_h = 60
colors = [(255,0,0), (0,255,0), (0,0,255), (255,255,0),
          (255,0,255), (0,255,255), (255,128,0), (128,0,255)]
bar_w = width // len(colors)
for i, c in enumerate(colors):
    draw.rectangle([i*bar_w, height-bar_h, (i+1)*bar_w, height], fill=c)

# Gradient
for x in range(width - 20):
    gray = int(x / (width - 20) * 255)
    draw.line([(x+10, height-bar_h-30), (x+10, height-bar_h-10)], fill=(gray,gray,gray))

# ── Convert and write ────────────────────────────────────
raw = bytearray(stride * height)
pixels = img.load()
for y in range(height):
    for x in range(width):
        r, g, b = pixels[x, y]
        offset = y * stride + x * Bpp
        if bpp == 16:
            # RGB565 little-endian
            struct.pack_into("<H", raw, offset,
                             ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3))
        else:
            # XRGB8888 little-endian
            struct.pack_into("<I", raw, offset,
                             0xFF000000 | (r << 16) | (g << 8) | b)

with open(fb_dev, "wb") as fb:
    fb.write(raw)
print(f"Wrote {len(raw):,} bytes to {fb_dev}")
EOF

sudo python3 dsi_draw.py

You should see a black screen with a cyan border, text, color bars, and a gradient on the DSI panel.

Checkpoint

The test pattern is visible on the DSI display with text and color bars.

Quick Noise Test

cat /dev/urandom | sudo tee /dev/fb0 > /dev/null
# Press Ctrl+C after you see noise — the "No space left" error is normal

5. Run DRM/KMS Applications

Concept: Since DSI uses the DRM/KMS path, any application that targets DRM works unchanged. SDL2, Qt EGLFS, and custom DRM applications all work.

SDL2 Applications

If you have built the SDL2 Dashboard or Level Display SDL2, run them on DSI:

export SDL_VIDEODRIVER=kmsdrm
./your_sdl2_app

SDL2 auto-selects the first connected display. If both DSI and HDMI are connected, you can specify the connector:

export SDL_VIDEODRIVER=kmsdrm
export SDL_VIDEO_KMSDRM_CONNECTOR_INDEX=1
./your_sdl2_app

Framebuffer Compatibility

The DSI display also appears as /dev/fb0 (or /dev/fb1 if HDMI is primary). The Python PIL scripts above write directly to this framebuffer — the same approach as the SPI Display tutorial but with XRGB8888 instead of RGB565.

Checkpoint

An SDL2 application (or PIL test pattern) is visible on the DSI display, running at full resolution.

6. Touch Input (I2C Capacitive)

Concept: The DSI panel's touch controller (FT5x06) uses I2C, not SPI. It supports multi-touch and requires no calibration — capacitive touch panels are factory-calibrated.

Install Tools

sudo apt install -y evtest

Identify the Touch Device

sudo evtest

The device list shows all input devices. Look for the FT5x06 touch controller:

Available devices:
/dev/input/event0:      vc4-hdmi-0
/dev/input/event1:      vc4-hdmi-0 HDMI Jack
/dev/input/event2:      vc4-hdmi-1
/dev/input/event3:      10-0038 generic ft5x06 (00)
/dev/input/event4:      vc4-hdmi-1 HDMI Jack

Select event3 (the ft5x06 device). The device info confirms a multitouch panel:

Input device name: "10-0038 generic ft5x06 (00)"
Supported events:
  Event type 1 (EV_KEY)
    Event code 330 (BTN_TOUCH)
  Event type 3 (EV_ABS)
    Event code 0 (ABS_X)        Min 0, Max 799
    Event code 1 (ABS_Y)        Min 0, Max 479
    Event code 47 (ABS_MT_SLOT)         Min 0, Max 9
    Event code 53 (ABS_MT_POSITION_X)   Min 0, Max 799
    Event code 54 (ABS_MT_POSITION_Y)   Min 0, Max 479
    Event code 57 (ABS_MT_TRACKING_ID)  Min 0, Max 65535
Properties:
  Property type 1 (INPUT_PROP_DIRECT)

Now tap the screen — you should see multitouch protocol B events:

Event: type 3 (EV_ABS), code 57 (ABS_MT_TRACKING_ID), value 12
Event: type 3 (EV_ABS), code 53 (ABS_MT_POSITION_X), value 241
Event: type 3 (EV_ABS), code 54 (ABS_MT_POSITION_Y), value 240
Event: type 1 (EV_KEY), code 330 (BTN_TOUCH), value 1
Event: -------------- SYN_REPORT ------------

Lifting the finger sends a tracking ID of -1 to release the slot:

Event: type 3 (EV_ABS), code 57 (ABS_MT_TRACKING_ID), value -1
Event: type 1 (EV_KEY), code 330 (BTN_TOUCH), value 0
Event: -------------- SYN_REPORT ------------
FT5x06 Driver and the "10-0038" Name

The device name 10-0038 generic ft5x06 (00) encodes how the kernel found it:

  • 10 — I2C bus 10 (the DSI ribbon cable carries I2C alongside the display lanes)
  • 0038 — I2C address 0x38 (the FT5x06's default slave address)
  • generic ft5x06 — the kernel's edt-ft5x06 driver (drivers/input/touchscreen/edt-ft5x06.c)

The driver uses multitouch protocol B — each finger gets a numbered slot (ABS_MT_SLOT) with its own tracking ID. The official display supports 10 simultaneous touch points (Max 9 means slots 0–9). The coordinate range (0–799, 0–479) maps directly to the panel's 800×480 pixels, so no userspace calibration is needed.

Unlike SPI resistive touch (XPT2046) which requires a calibration matrix because the analog touch film's coordinates drift with temperature and pressure, capacitive panels like the FT5x06 are factory-calibrated — the controller's firmware maps touch positions to fixed pixel coordinates.

The INPUT_PROP_DIRECT property tells userspace (libinput, SDL2) that this is a direct-input device (touchscreen) rather than indirect (trackpad), so coordinates map 1:1 to the display without pointer acceleration.

Capacitive vs Resistive Touch

Feature SPI Display (XPT2046) DSI Display (FT5x06)
Technology Resistive Capacitive
Bus SPI I2C (via DSI ribbon)
Multi-touch No (single point) Yes (up to 10 points)
Calibration needed Yes (matrix) No (factory-calibrated)
Glove support Yes (pressure-based) No (needs conductive contact)
Wear over time Degrades (film layers) Stable (glass surface)

Touch Drawing App

With touch verified, combine it with framebuffer drawing. This script draws dots where you touch, with a color picker and clear button:

# Copy from course source files
cp src/embedded-linux/solutions/dsi-display/dsi_touch_draw.py ~/
sudo python3 ~/dsi_touch_draw.py

Or if you completed the SPI Display touch drawing app, compare the two scripts. The DSI version is simpler because:

  • No calibration needed — coordinates from ABS_MT_POSITION_X/Y are already in pixels (0–799, 0–479), so the SWAP_XY/INVERT_X/INVERT_Y logic is gone
  • Multitouch protocol B — reads ABS_MT_POSITION_X/Y instead of ABS_X/Y with ADC values
  • XRGB8888 — 4 bytes per pixel with struct.pack("<I", 0xFF000000 | (r<<16) | (g<<8) | b) instead of RGB565's 2-byte packing
Checkpoint

evtest shows touch coordinates when you tap the DSI display. The touch drawing app renders dots that follow your finger.

7. GPU Rendering

Concept: Unlike SPI displays, DSI panels have full GPU acceleration — OpenGL ES, hardware compositing, VSync, and page flipping all work.

Confirm OpenGL ES

sudo apt-get install -y mesa-utils
glxinfo | grep "OpenGL renderer"

Or use the EGL info tool:

eglinfo 2>/dev/null | head -20

SDL2 Hardware Acceleration

SDL2 applications using the kmsdrm video driver get hardware-accelerated rendering on DSI:

export SDL_VIDEODRIVER=kmsdrm
export SDL_RENDER_DRIVER=opengles2
./your_sdl2_app

Qt EGLFS

Qt applications using the EGLFS platform plugin render directly via EGL on the DSI display:

export QT_QPA_PLATFORM=eglfs
./your_qt_app

Feature Comparison: SPI vs DSI

Feature SPI Display DSI Display
GPU scan-out No — CPU only Yes — full GPU path
OpenGL ES Not available Available
VSync / page flip Not available Available (DRM)
Hardware compositing Not available Available (DRM planes)
Maximum FPS (full frame) ~13 FPS (SPI bandwidth limit) 60 FPS (panel refresh rate)
Tearing Cannot be avoided Eliminated via VSync
Suitable for Status displays, simple UI Dashboards, animations, video
Checkpoint

You can confirm GPU acceleration is available on the DSI display. If you have an SDL2 or Qt app, it runs at full frame rate with no tearing.

8. Dual Display: DSI + HDMI

Concept: The Pi's GPU has multiple CRTCs (display controllers). DSI and HDMI connect to separate CRTCs, so both can be active simultaneously with independent content.

Verify Both Connectors

sudo modetest -M vc4 -c

Both DSI-1 and HDMI-A-1 should show connected status (assuming both displays are plugged in).

Run Content on Each Display

You can display different content on each:

# Test pattern on DSI (use your connector@crtc IDs)
sudo modetest -M vc4 -a -s <DSI_ID>@<DSI_CRTC>:800x480 &

# Test pattern on HDMI (different connector@crtc)
sudo modetest -M vc4 -a -s <HDMI_ID>@<HDMI_CRTC>:800x480 &

Use Cases for Dual Display

  • Development: HDMI for desktop/terminal, DSI for the embedded application
  • Product: DSI for the user-facing UI, HDMI for a technician/debug display
  • Mirroring: Same content on both (via compositor or application logic)
Checkpoint

Both DSI and HDMI show output simultaneously. Each displays independent content.

Stuck?
  • Only one display works — check that /boot/firmware/config.txt has max_framebuffers=2 (add it if missing, then reboot)
  • Second display flickers — the GPU may not have enough memory for two large framebuffers; try gpu_mem=128 in config.txt
What max_framebuffers and gpu_mem Control

These are firmware-level settings parsed by the Pi's VideoCore bootloader before Linux starts:

  • max_framebuffers=2 tells the firmware to allocate CRTCs (display pipelines) for two simultaneous outputs. By default, only one is active. This setting is read by the vc4 DRM driver during probe to determine how many connectors to enable.
  • gpu_mem=128 reserves 128 MB of the Pi's RAM for the GPU. Each active framebuffer needs width × height × bpp bytes in GPU memory. Two 800×480×32bpp buffers (double-buffered) need 4 × 800 × 480 × 4 = ~6 MB, well within 128 MB. The default 76 MB is usually sufficient, but increase it if you see allocation failures in dmesg.

These settings have no equivalent in mainline Linux — they are specific to the Pi's firmware-managed memory split. On other SoCs with unified memory (i.MX, STM32MP), the DRM driver allocates buffers from the main CMA (Contiguous Memory Allocator) pool, configured via cma=128M on the kernel command line.

9. Performance Comparison

Concept: DSI should match HDMI performance since both use the GPU scan-out path. SPI is the outlier due to its CPU-driven architecture.

Three-Way Measurement Table

Fill in by running your frame timing tests on each display interface:

Metric SPI Display DSI Display HDMI Display
Resolution 480 × 320 800 × 480 800 × 480
Color depth 16 bpp (RGB565) 32 bpp (XRGB8888) 32 bpp (XRGB8888)
Frame size (bytes) _ _ _
Frame time (ms) _ _ _
Effective FPS _ _ _
CPU usage (%) _ _ _
GPU accelerated No Yes Yes
Tearing visible _ _ _
Checkpoint

Your three-way comparison table is filled in. DSI and HDMI should show similar performance (60 FPS, low CPU), while SPI shows ~10-15 FPS with high CPU usage.

What Just Happened?

You connected a display that uses the same GPU-accelerated rendering path as HDMI, but through a different physical interface:

DSI:  App → GPU render → DRM buffer → Display controller → DSI lanes → Panel
HDMI: App → GPU render → DRM buffer → Display controller → HDMI encoder → Monitor
SPI:  App → CPU render → RAM → fbtft driver → SPI bus → Panel controller → LCD

DSI and HDMI share everything up to the final output stage. The GPU renders frames into a DRM buffer, the display controller scans them out during VBlank, and the only difference is whether the pixels travel over DSI differential lanes or HDMI TMDS encoding. This is why your SDL2 and Qt applications work on DSI without modification.

SPI is the fundamentally different path — the GPU cannot push pixels over SPI, so the CPU must handle every transfer.

Challenges

Challenge 1: Rotate to Portrait

Some applications work better in portrait orientation. Configure the DSI display for 480×800 by adding display_lcd_rotate=1 to /boot/firmware/config.txt. Verify with modetest that the mode changes, and test an SDL2 application in portrait mode.

Challenge 2: Mirror Dashboard on Both Screens

Write a script that runs the same SDL2 dashboard on both DSI and HDMI simultaneously. Hint: you may need two separate application instances, each targeting a different DRM connector, or use a compositor like Weston to mirror output.

Challenge 3: Runtime Display Detection

Write a shell script that detects which displays are connected at boot and configures the application accordingly:

#!/bin/bash
# Detect connected displays and launch appropriate UI
for connector in /sys/class/drm/card*-*/status; do
    name=$(basename $(dirname $connector))
    status=$(cat $connector)
    echo "$name: $status"
done

Extend this to automatically start the dashboard on whichever display is connected.

Solution Files

Note

src/embedded-linux/solutions/dsi-display/ — contains:

  • dsi_draw.py — test pattern with color bars and gradient
  • dsi_benchmark.py — framebuffer write speed measurement
  • dsi_touch_draw.py — complete touch drawing app with color picker, clear button, line drawing, and latency measurement
  • dsi_dashboard.py — live system dashboard (CPU, memory, temperature, disk, IP)

Deliverable

  • [ ] DSI display showing DRM/KMS test pattern or application output
  • [ ] Touch input verified with evtest (multi-touch events)
  • [ ] Touch drawing app running — dots appear where you tap
  • [ ] Three-way comparison table (SPI vs DSI vs HDMI) filled in
  • [ ] Brief note: one sentence explaining why DSI and HDMI share the same rendering path

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