Tech

Raspberry Pi 4 now also as a Compute Module (CM4)

The Raspberry Pi Foundation presents the Raspberry Pi Compute Module 4 (CM4). Like its predecessor, the CM3, it is intended for use as an embedded system in other devices and is available from US $ 25. There are a total of 32 variants with or without WLAN adapter, with or without or with up to 32 GByte eMMC flash and with 1, 2, 4 or 8 GByte RAM.

Compared to the CM3 and its predecessor, the CM, the CM4 has a different, significantly smaller connector. In order to be able to use a CM4 on a CM3 base board, there are adapters, for example from Gumstix.

Raspi mastermind Upton announced the CM4 in a blog. Accordingly, the same ARM SoC Broadcom BCM2711 with four Cortex-A72 cores sits on the CM4 as on the Raspberry Pi 4. However, the USB 3.0 controller is missing. Instead, a PCI Express 2.0 lane (PCIe 2.0 x1) can be used. A USB 3.0 adapter could also be retrofitted to a baseboard.


Raspberry Pi Compute Module 4 IO Board with attached CM4 and PCIe-x1 socket.
(Image: Raspberry Pi Foundation)

The cheapest lite versions of the CM4 come without eMMC Flash and without a WLAN adapter. Gigabit Ethernet is always included.

The in-house “IO Board” of the Raspberry Pi Foundation should be available from $ 35. It doesn’t have a USB 3.0 controller, but a PCIe x1 socket for a PCI Express card.

It also provides the 40-pin pin header typical of Raspi as well as a microSD card reader, Ethernet socket, two HDMI sockets, two USB 2.0 sockets, a 12-volt power connection, DSI and CSI connections for camera and display as well as a battery-backed real-time clock (RTC).

Other providers will bring out their own CM4 base boards, also known as break-out boards. Gumstix, for example, offers that $ 130 Raspberry Pi CM4 Development Board, which among other things has an M.2 socket for an M.2-2280 SSD.


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The Raspberry Pi Foundation also sells an antenna kit for the CM4.

The Compute Module is actually intended for installation in other devices, the developers of which are designing their own base boards. The Raspberry Pi Foundation provides the necessary design data in KiCad format. There is a mechanical description in STEP format for the CM4. The CM4 board has edge lengths of 4 and 5.5 centimeters.

The CM4 should be and was available at least until January 2028 certified according to several standards.


(ciw)

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