Raspberry Pi Development
From CM4 carrier board to production embedded Linux — Raspberry Pi engineered for industrial IoT, machine vision, and custom product deployment.
What We Build on This Platform
CM4 Carrier Board Design
Custom carrier board with PCIe, CSI, DSI, USB, Ethernet, and custom GPIO routed from the CM4's 200-pin high-density connector.
Raspberry Pi 5 Integration
Pi 5 and RP1 I/O controller integration for development, prototyping, and products where the full board form factor is acceptable.
Embedded Linux for Pi
Raspberry Pi OS customisation, Buildroot, and Yocto for production Pi images with read-only rootfs and overlayfs.
Industrial Gateway Applications
IoT gateway, protocol bridge, and edge compute on CM4 with industrial interfaces: CAN Bus, RS-485, Modbus RTU.
Machine Vision on Pi
Camera interface, libcamera integration, image processing, and edge AI inference on Pi hardware with CSI camera modules.
Qt and GUI Applications
Qt 5/6 embedded application development for Raspberry Pi touchscreen products with hardware-accelerated display rendering.
Custom HAT Design
Raspberry Pi HAT with EEPROM, GPIO, SPI, I2C, and hardware add-on design compliant with the HAT specification.
Production Provisioning
CM4 eMMC production imaging via usbboot, configuration injection, and fleet management agent for deployed products.
How Ankh Uses This Platform
Form Factor Selection
Pi 5 for development, prototyping, and lower-volume products where the full board form factor is acceptable. CM4 for production products requiring custom carrier board design, compact form factor, or industrial interface requirements. CM4 variant selection: eMMC versus Lite, RAM from the application requirement, Wi-Fi/BLE built-in versus custom RF module on carrier.
CM4 Carrier Board Design
Custom carrier board designed from the PCB schematic integrating the CM4 200-pin connector, power supply, PCIe for NVMe storage, CSI FPC connectors for camera interfaces, HDMI or DSI display output, USB hub, Ethernet PHY, and product-specific custom interfaces. Mechanical envelope matched to the product enclosure.
OS Image Configuration
Raspberry Pi OS Lite for headless products, or full Raspberry Pi OS with Qt for GUI products. Image customised with cloud-init or custom firstboot script for provisioning. Read-only rootfs with overlay for production reliability. Custom kernel module for product-specific hardware. Systemd service configuration for application auto-start.
Application Development
C++, Python, or Qt application for the specific product function. Camera application using libcamera for CSI camera products. OpenCV or custom pipeline for image processing products. GPIO library gpiod for hardware interface. Industrial protocol library libmodbus or socketcan for gateway products.
Production Imaging and Fleet Management
Production master image created and signed. USB mass storage programming tool usbboot for CM4 eMMC for manufacturing line programming. Configuration injection for device-unique serial number, certificates, and application configuration. Remote management via SSH, Ansible, or custom fleet management agent for deployed Pi products.
Deep Technical Capability
PCIe on CM4 for NVMe and Custom Peripherals
The CM4's single PCIe Gen2 x1 lane provides 5Gbps theoretical bandwidth that makes NVMe storage, PCIe-attached FPGA, and custom PCIe endpoint devices practical on a Raspberry Pi platform. The carrier board PCIe implementation requires correct AC coupling capacitor values at each PCIe data lane (100nF for Gen2), correct trace impedance (85Ω differential), and correct clock source — the CM4 provides a 100MHz PCIe reference clock that must be routed with controlled impedance and correct trace length matching to the endpoint device. Ankh designs CM4 carrier board PCIe implementations from the PCIe base specification and the CM4 hardware design guide — including the specific AC coupling network, the impedance-controlled differential pair routing, and the power supply sequence for the PCIe endpoint device — so the PCIe link trains at first power-on rather than requiring debug that the Raspberry Pi's locked bootloader makes impossible.
Camera Interface on CM4 for Machine Vision Products
The CM4 provides two MIPI CSI-2 interfaces through 15-pin and 22-pin FPC connectors. The CSI interface is served by the Unicam peripheral of the BCM2711, accessed through the libcamera stack that replaced the legacy MMAL camera API. A custom camera sensor requires a libcamera IPA module and a kernel driver for the sensor's I2C register interface — both developed from the sensor's datasheet. Ankh develops custom libcamera IPA modules and kernel sensor drivers for non-standard camera sensors on CM4, enabling industrial and scientific cameras with specific pixel formats, frame rate requirements, or exposure control modes that the standard Raspberry Pi camera software stack does not support.
Production Reliability with CM4 eMMC and Read-Only Rootfs
The Raspberry Pi product deployed in an industrial or commercial environment with a microSD card root filesystem accumulates file system corruption risk from power loss events — the SD card's write cache and FAT32 filesystem on /boot are particularly vulnerable. The CM4 with eMMC eliminates SD card failure modes, but eMMC with a read-write rootfs still accumulates corruption risk. Ankh configures CM4 production images with a read-only squashfs rootfs on the eMMC system partition, an overlayfs upper layer on a separate data partition for mutable files, and a factory reset mechanism that clears the overlayfs upper layer to restore the device to factory defaults — so the production CM4 product survives power loss events in the same way that embedded Linux products on dedicated MCU platforms do.
Products Built on This Platform
AI Vision Systems
CM4 as edge compute gateway for multi-camera machine vision pipeline with USB 3.0 to industrial frame grabber.
View ProductData Loggers
CM4 for high-throughput data logger with NVMe storage, USB 3.0 download, and Ethernet connectivity.
View ProductIndustrial Equipment Monitoring
CM4 with Qt 6 touchscreen application for industrial HMI panel.
View ProductSmart Home Devices
CM4 as smart home hub and Thread border router gateway.
View ProductSmart Agriculture
CM4 as farm IoT gateway aggregating LoRaWAN and MQTT sensor data.
View ProductThe CM4 carrier board is an electronics design programme, not a breakout board
The CM4 carrier board that connects the CM4's 200-pin connector to the product's specific peripherals requires the same electronics design discipline as any other custom PCB — controlled impedance routing for PCIe and MIPI CSI lanes, correct power supply sequencing for the CM4's VDDHD and core supply rails, correct HDMI termination for the specific display panel, and USB hub topology for the required port count. A CM4 carrier board designed without this discipline fails to train the PCIe link, produces MIPI CSI image corruption, or browns out the CM4 during USB storage enumeration. Ankh designs CM4 carrier boards as engineering projects with the same schematic review, signal integrity analysis, and DFM discipline as any other high-speed digital PCB.
Raspberry Pi OS is not a production OS without hardening
Raspberry Pi OS with default configuration enables SSH with default credentials, runs the avahi-daemon, the triggerhappy button daemon, and the fake-hwclock service that are irrelevant to most products, and mounts the boot partition read-write at every boot. A production product requires SSH keys replaced with product-specific certificates, unnecessary services disabled, the boot partition mounted read-only after initial configuration, and automatic security updates replaced with a controlled update mechanism. Ankh delivers production Pi images hardened for the specific application — not Raspberry Pi OS with the default student workstation configuration.
Mass production programming of CM4 eMMC requires purpose-built tooling
The CM4 with eMMC cannot be programmed with a standard SD card image writer — it requires the CM4 to boot in USB mass storage mode via the usbboot utility. Programming 500 CM4 units on a manufacturing line requires a production programming fixture with the correct USB hub, a reliable usbboot session management script that handles CM4 enumeration variability, and a programming verification step that reads back the programmed eMMC content before the CM4 is installed in the product enclosure. Ankh develops production CM4 programming tooling as part of every CM4-based product programme — not as an afterthought when the contract manufacturer asks how to program the modules.