Strato Pi CM v3 and Duo v3

Sfera Labs’ Strato Pi CM v3 and Strato Pi CM Duo v3 bring in several innovations, including the support for the Raspberry Pi Compute Module 4S (CM4S). Based on the same CPU as the Raspberry Pi 4 Model B, Compute Module 4S is significantly more powerful than Compute Module 3+ and the older Compute Module 3. The Strato Pi CM is compatible with Compute Module 3, 3+, and 4S with embedded eMMC, it provides enhanced protection of the RS-485 lines, and it has a redesigned real-time-clock circuit with much-improved timekeeping accuracy and extended backup battery life.

Strato Pi CM v3 features a hardware watchdog, two USB ports that can be individually power-cycled, a secure element chip/crypto chip enabling the storage of security keys and the implementation of other security features, and the microcontroller’s firmware can be upgraded remotely from the Pi itself. As Strato Pi CM v3 lacks the microSD sockets, it is incompatible with the Compute Module Lite versions.

Strato Pi CM Duo adds two microSD card slots and an innovative high-speed switch matrix that allows the Raspberry Pi Compute Module Lite to boot the operating system from either SD card while at the same time having full access to the other SD card for additional storage or to keep an up-to-date failover image of the operating system and data. This architecture enables performing a full-image upgrade of the Pi's operating system on one SD card while the system runs from the other. Following verification of the new image, the Strato Pi CM Duo can restart the Compute Module, booting from the second SD card. If the boot process is unsuccessful, it will safely roll back to the original SD card.

Features

• 2-module DIN rail case
• Power supply and serial connections on a pluggable terminal block
• 9 V_DC to 28 V_DC power supply, with surge and reverse polarity protection and 1.1 A resettable fuse
• Up to 1.9 A max continuous current (3 A peaks) to the 5 V Raspberry Pi Compute Module power supply input pins at 24 V_DC
• Standard RS-485 interface to the Raspberry Pi serial line, with optoisolator and electrostatic discharge protection
• 2x USB 2.0 Type-A ports with individual power control and fault detection
• 10/100 Ethernet port
• Embedded Raspberry Pi Compute Module eMMC Flash memory (8 GB, 16 GB, or 32 GB)
• Hardware watchdog, fully independent from the Raspberry Pi Compute Module, controlled via GPIO
• Real-time clock (RTC) with replaceable back-up battery
• Embedded Microchip ATECC608 secure element chip
• Integrated boot loader for the Strato Pi microcontroller, allowing in-field firmware upgrades directly from the Raspberry Pi
• GPIO-controlled LED
• LEDs for power supply and serial line activity
• Recessed pushbutton is hidden behind the front panel and connected to a GPIO pin