Raspberry Pi alternative, Milk-V, has previously released three other single-board computers, many of which share more than a passing resemblance to our favorite single-board computer. One of the trio was the Milk-V Mars, a board that looks like a Raspberry Pi 3B+, albeit with a white PCB. Another Milk-V Mars board has dropped into the range, but this board, the Milk-V Mars CM, apes the Raspberry Pi Compute Module 4 form factor.
The show's star is the JH7110 SoC, specifically the RISC-V-based CPU. This is the same CPU as the Milk-V Mars. This quad-core CPU is capable of up to 1.5 GHz and is supported by between 2 and 8GB of LPDDR4 RAM.
| SoC | StartFive JH7110 64bit SoC with Quad-Core RV64GC at up to 1.5 GHz |
| RAM | 2 / 4 / 8GB LPDDR4 |
| Storage | 8 / 16 / 32GB eMMC |
| Row 3 - Cell 0 | 1x SDIO 2.0 |
| Row 4 - Cell 0 | 1x Nor Flash for boot (16M) |
| Ports | 1 x HDMI, 1 x MIPI DSI (4-lane) via breakout |
| Row 6 - Cell 0 | Camera via MIPI CSI (2-lane) via breakout |
| Row 7 - Cell 0 | 3 x USB 3, 1 x USB 2 via breakout |
| Row 8 - Cell 0 | 1x PCIe 1-lane Host, Gen 2 (5Gbps) via breakout |
| Networking | Wi-Fi 5 and Bluetooth 5.2 via AP6256 |
| Row 10 - Cell 0 | Gigabit Ethernet (PoE) via breakout |
| GPIO | 40 pin GPIO via breakout |
| Power | 5V |
| Dimensions | 55 x 40 mm |
On the Milk-V product page, we can see an image that shows the Milk-V Mars CM connected to a Compute Module 4 IO board via 2 x 100-pin connectors, and this could mean that it is electrically compatible with breakout boards designed for the CM4.
The page also states "1x SDIO 2.0 (options to eMMC)" as a storage option but fails to clarify if that means there is a micro SD card slot or various eMMC capacities to choose from. If Milk-V is following the Raspberry Pi playbook, then there are most likely versions with eMMC and "lite" versions with micro SD. We need to go to a reseller to confirm the three models that will be available and their RAM/storage configurations.
We can confirm from the official product page that the Milk-V Mars CM has an onboard Gigabit Ethernet IC; of course, this can only be used with an IO board. Wi-Fi and Bluetooth are provided via an AP6256 IC. This chip connects to the SoC via SPI and provides Wi-Fi 802.11ac/a/b/g/n and Bluetooth 5.2 in one handy package. Unlike the Compute Module 4, which uses an on-chip antenna, an external antenna connection is required.
| RAM | eMMC Storage | Price |
|---|---|---|
| 2GB | 8GB | $34 |
| 4GB | 16GB | $49 |
| 8GB | 32GB | $79 |
We need a breakout board to use the Milk-V Mars CM. The official Raspberry Pi CM4 IO board seems compatible and can connect to HDMI, Ethernet, micro SD, and PCIe. It also provides access to the GPIO. We have a 40-pin GPIO (6 x UART, 8 x PWM, 7 x I2C, SPI and I2S). Are these GPIO pins compatible with the best Raspberry Pi HATs? We do not know. Electrically, they may be consistent, but software support may be a dealbreaker.
The Milk-V Mars CM is currently on pre-sale, with units expected to ship from September 30.
