Raspberry Pi aims the CM4S at industrial users migrating from earlier Compute Modules. Loosely based on Raspberry Pi 4 Model B electronics, it comes in the same DDR2-SODIMM-like form factor as the Compute Module 3 and 3+.
Sfera’s CM4S-based computers are Strato Pi CM v3 and CM Duo v3, which come in 8, 16 and 32Gbyte versions.
“Strato Pi CM v3 and CM Duo v3 provide users with the improved performance of CM4S, which is significantly more powerful than CM 3+ or CM 3,” according to the company. “The models feature enhanced protection for the RS-485 lines, and a re-designed real-time-clock circuit with improved time-keeping accuracy and extended back-up battery life. Each retains the same watchdog and isolated RS-485 port that has been built into previous generations of Strato Pi CM.”
Each of the two USB ports gets its own circuit fault protection and detection, and they can individually be power-cycled – enabling externally-connected USB-powered devices to be turned off and back on again should they lock-up, without someone physically unplugging them.
A ‘secure element’ chip is included for storing security keys and, through a pre-installed boot loader and supplied utilities, internal microcontroller firmware can be upgraded remotely from the Pi itself, with the Pi remaining functional during the upgrade, said Sfera.
The Duo version gets its name from having twin SDcard slots, and it has a switch matrix that allows the Compute Module to boot its operating system from either SD card, while retaining access to the other SD card for additional storage or to keep a fail-over image of both operating system and data.
Duo “architecture enables a full-image upgrade of the Pi’s operating system to be performed on one SD card while the system runs from the other”, said Sfera. “Following verification of the new image, the 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.”
The company expects the computers to be used in industrial and IoT applications ranging from energy management and data collection to building automation and control of marine systems.
The Strato Pi CM v3 and its Duo cousin can be found on this webpage