Eye Remote Hardware & Interfaces
Supported Hardware
Display Module
| Component |
Model |
Specifications |
| Display |
Pimoroni HyperPixel 2.1 Round |
480×480 IPS, capacitive touch |
| Controller |
ST7701S |
DPI interface, SPI init required |
| Interface |
40-pin GPIO |
Full GPIO header required |
| Touch |
I2C |
Address 0x15 on I2C-10 |
Computing Units
| Board |
SoC |
Status |
Notes |
| Raspberry Pi Zero W |
BCM2835 (ARMv6) |
✅ Recommended |
512MB RAM, WiFi, BT |
| Raspberry Pi Zero 2 W |
BCM2710 (ARMv8) |
⚠️ Untested |
512MB RAM, quad-core |
| Raspberry Pi Zero WH |
BCM2835 |
✅ Works |
Pre-soldered headers |
Note: Pi Zero W is recommended for power efficiency. Pi 3/4/5 not supported due to form factor.
Hardware Connections
GPIO Pinout (HyperPixel 2.1 Round)
┌─────────────────────────────────────────────────────────────┐
│ 40-pin GPIO Header │
├──────┬──────┬───────────────────────────────────────────────┤
│ Pin │ GPIO │ Function │
├──────┼──────┼───────────────────────────────────────────────┤
│ 1 │ 3V3 │ Power │
│ 2 │ 5V │ Power (display backlight) │
│ 3 │ 2 │ I2C1 SDA (touch controller) │
│ 5 │ 3 │ I2C1 SCL (touch controller) │
│ 6 │ GND │ Ground │
│ 10 │ 15 │ SPI CE1 (LCD chip select) │
│ 11 │ 17 │ LCD CLK (SPI clock) │
│ 13 │ 27 │ LCD MOSI (SPI data) │
│ 15 │ 22 │ LCD DC (data/command select) │
│ 19 │ 10 │ SPI MOSI (alt function) │
│ 21 │ 9 │ SPI MISO (alt function) │
│ 23 │ 11 │ SPI CLK (alt function) │
│ 35 │ 19 │ Backlight PWM │
│ 36 │ 16 │ LCD Reset │
│ 37 │ 26 │ Touch interrupt │
│ 38 │ 20 │ DPI DE │
│ 40 │ 21 │ DPI CLK │
│ 4-40 │ ... │ DPI data (RGB666) │
└──────┴──────┴───────────────────────────────────────────────┘
USB OTG Connection
Pi Zero W
┌───────────────────────────────┐
│ PWR DATA HDMI │
│ (○) (●) (○) │
│ ↑ │
│ USB OTG data port │
│ Connect here! │
└───────────────────────────────┘
│
│ Micro-USB cable
│
┌────────────▼────────────────┐
│ SecuBox Host │
│ USB-A port (any) │
└─────────────────────────────┘
⚠️ WARNING: Do NOT use the PWR port for OTG!
The DATA port (middle) must be used.
Network Interfaces
USB OTG Network (Primary)
| Parameter |
Value |
| Interface |
usb0 (Eye) / secubox-round (Host) |
| Eye IP |
10.55.0.2/30 |
| Host IP |
10.55.0.1/30 |
| Gateway |
10.55.0.1 |
| Protocol |
CDC-ECM (Ethernet over USB) |
USB Serial Console (Rescue)
| Parameter |
Value |
| Device (Host) |
/dev/ttyACM0 |
| Device (Eye) |
/dev/ttyGS0 |
| Baud Rate |
115200 |
| Protocol |
CDC-ACM (Serial over USB) |
# Connect from SecuBox host
screen /dev/ttyACM0 115200
# or
minicom -D /dev/ttyACM0 -b 115200
WiFi (Fallback)
| Parameter |
Value |
| Interface |
wlan0 |
| Mode |
Client (WPA2-PSK) |
| Hostname |
secubox-round.local |
| mDNS |
Avahi (enabled) |
Complete Display Requirements
Hardware Stack
┌─────────────────────────────────────────────────────────────┐
│ Display Stack │
├─────────────────────────────────────────────────────────────┤
│ Layer 7: Chromium Browser (kiosk mode, fullscreen) │
├─────────────────────────────────────────────────────────────┤
│ Layer 6: HTML5 Dashboard (Canvas API, WebSocket) │
├─────────────────────────────────────────────────────────────┤
│ Layer 5: nginx (localhost:8080 → proxy to API) │
├─────────────────────────────────────────────────────────────┤
│ Layer 4: Openbox Window Manager (minimal, no decorations) │
├─────────────────────────────────────────────────────────────┤
│ Layer 3: X11 Server (xserver-xorg-video-fbdev) │
├─────────────────────────────────────────────────────────────┤
│ Layer 2: LightDM Display Manager (autologin: secubox) │
├─────────────────────────────────────────────────────────────┤
│ Layer 1: Linux Framebuffer (/dev/fb0, 480x480 RGB666) │
├─────────────────────────────────────────────────────────────┤
│ Layer 0: HyperPixel DPI Interface (24-bit parallel RGB) │
└─────────────────────────────────────────────────────────────┘
Required Packages
| Package |
Purpose |
Size |
xserver-xorg |
X11 server |
~2MB |
xserver-xorg-video-fbdev |
Framebuffer driver |
~20KB |
xinit |
X initialization |
~100KB |
lightdm |
Display manager |
~1MB |
openbox |
Window manager |
~1MB |
chromium-browser |
Kiosk browser |
~200MB |
unclutter |
Hide mouse cursor |
~20KB |
x11-xserver-utils |
xset, xrandr, etc |
~200KB |
nginx |
Web server for dashboard |
~1MB |
pigpio |
GPIO control daemon |
~500KB |
python3-pigpio |
Python GPIO bindings |
~100KB |
fonts-dejavu-core |
Dashboard fonts |
~3MB |
Required Services
| Service |
Purpose |
Depends On |
pigpiod |
GPIO daemon for LCD init |
- |
hyperpixel2r-init |
ST7701S LCD initialization |
pigpiod |
lightdm |
Display manager |
hyperpixel2r-init |
nginx |
Serve dashboard HTML |
- |
Boot Sequence
1. Kernel boots (bcm2708-rpi-zero-w.dtb)
↓
2. DPI interface initialized (config.txt dpi_timings)
↓
3. systemd starts multi-user.target
↓
4. pigpiod.service starts (GPIO daemon)
↓
5. hyperpixel2r-init.service runs
- Connects to pigpiod
- Sends SPI commands to ST7701S
- Enables backlight
- Display shows framebuffer content
↓
6. lightdm.service starts
- Starts X11 server on :0
- Auto-logs in as 'secubox' user
↓
7. openbox-session starts
- Executes ~/.config/openbox/autostart
- Disables screensaver (xset s off)
- Hides cursor (unclutter)
↓
8. chromium-browser --kiosk http://localhost:8080
- Fullscreen, no UI elements
- Dashboard renders
↓
9. Dashboard connects to SecuBox API
- Fetches metrics every 2 seconds
- Renders on Canvas
Critical Configuration Files
| File |
Purpose |
/boot/config.txt |
DPI timings, overlays, GPIO |
/boot/cmdline.txt |
Kernel modules (dwc2, libcomposite) |
/etc/systemd/system/hyperpixel2r-init.service |
LCD init service |
/usr/bin/hyperpixel2r-init |
ST7701S init script |
/etc/lightdm/lightdm.conf.d/50-autologin.conf |
Auto-login config |
/home/secubox/.config/openbox/autostart |
Kiosk startup script |
/etc/nginx/sites-available/secubox-round |
Dashboard web server |
Display Configuration
Legacy DPI Mode (Required for Pi Zero W)
The HyperPixel 2.1 Round uses a DPI (parallel) interface that requires specific timing configuration. KMS (Kernel Mode Setting) does not work on Pi Zero W.
/boot/config.txt
# HyperPixel 2.1 Round - Legacy DPI
dtoverlay=hyperpixel2r
enable_dpi_lcd=1
display_default_lcd=1
dpi_group=2
dpi_mode=87
dpi_output_format=0x7f216
dpi_timings=480 0 10 16 55 480 0 15 60 15 0 0 0 60 0 19200000 6
framebuffer_width=480
framebuffer_height=480
display_rotate=0
# I2C for touch
dtparam=i2c_arm=on
dtparam=spi=on
ST7701S LCD Initialization
The LCD controller requires SPI commands at boot to initialize. This is handled by hyperpixel2r-init service.
Boot sequence:
1. pigpiod.service starts (GPIO daemon)
2. hyperpixel2r-init.service runs (SPI init)
3. framebuffer becomes available
4. lightdm.service starts (X11)
5. Chromium kiosk launches
DPI Timing Parameters
| Parameter |
Value |
Description |
| H pixels |
480 |
Horizontal resolution |
| H front porch |
10 |
H blank before sync |
| H sync |
16 |
H sync pulse width |
| H back porch |
55 |
H blank after sync |
| V pixels |
480 |
Vertical resolution |
| V front porch |
15 |
V blank before sync |
| V sync |
60 |
V sync pulse width |
| V back porch |
15 |
V blank after sync |
| V sync polarity |
0 |
Active low |
| H sync polarity |
0 |
Active low |
| DE polarity |
0 |
Active high |
| Pixel clock |
19200000 |
19.2 MHz |
| Clock edge |
6 |
Sample on rising edge |
USB Gadget Modes
The Eye Remote supports multiple USB gadget configurations:
Mode: start (Default)
┌─────────────────────────────┐
│ USB Composite │
├─────────────────────────────┤
│ ECM (Ethernet) usb0 │
│ ACM (Serial) ttyGS0 │
└─────────────────────────────┘
Mode: tty (HID Keyboard)
┌─────────────────────────────┐
│ USB HID │
├─────────────────────────────┤
│ HID Keyboard hidg0 │
│ Can type on host │
└─────────────────────────────┘
Mode: debug (Network + Storage)
┌─────────────────────────────┐
│ USB Composite │
├─────────────────────────────┤
│ ECM (Ethernet) usb0 │
│ ACM (Serial) ttyGS0 │
│ Mass Storage debug.img │
└─────────────────────────────┘
Mode: flash (Bootable USB)
┌─────────────────────────────┐
│ USB Mass Storage │
├─────────────────────────────┤
│ Boot image only │
│ Host sees USB drive │
└─────────────────────────────┘
Mode: auth (FIDO2)
┌─────────────────────────────┐
│ USB FIDO2 │
├─────────────────────────────┤
│ FIDO2/U2F Security Key │
│ WebAuthn compatible │
└─────────────────────────────┘
Power Requirements
| State |
Current |
Notes |
| Boot |
~400mA |
Peak during initialization |
| Idle |
~150mA |
Display on, no activity |
| Active |
~250mA |
WiFi + display + CPU |
| Sleep |
~100mA |
Display dimmed |
Power source: USB 5V from host (via DATA port)
Note: Ensure host USB port provides at least 500mA. Use powered hub if needed.
Troubleshooting
Display Issues
| Symptom |
Cause |
Solution |
| Black screen |
KMS enabled |
Use legacy DPI mode |
| White screen |
ST7701S not initialized |
Check pigpiod + hyperpixel2r-init |
| Flickering |
Wrong DPI timings |
Verify config.txt settings |
| No touch |
I2C not enabled |
Check dtparam=i2c_arm=on |
Network Issues
| Symptom |
Cause |
Solution |
| No usb0 |
Gadget not loaded |
Check secubox-otg-gadget.service |
| No IP |
usb0-up failed |
Check /var/log/usb0-up.log |
| Host no interface |
udev rule missing |
Check /etc/udev/rules.d/90-secubox-otg.rules |
USB Issues
| Symptom |
Cause |
Solution |
| Not recognized |
Wrong port |
Use DATA port (middle) |
| Disconnects |
Power insufficient |
Use powered hub |
| No serial |
ACM not loaded |
Check libcomposite module |
Hardware Revisions
HyperPixel 2.1 Round
| Version |
Changes |
Compatibility |
| v1.0 |
Original release |
✅ Works |
| v2.0 |
Improved touch |
✅ Works |
| v2.1 |
Current production |
✅ Recommended |
Eye Remote Board Compatibility
| Version |
Pi Zero W |
Pi Zero 2 W |
Notes |
| v1.x |
✅ |
⚠️ Untested |
KMS mode (broken) |
| v2.0 |
✅ |
⚠️ Untested |
Legacy DPI mode |
CyberMind · SecuBox Eye Remote Hardware Guide · April 2026
CyberMind-FR
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