The Radxa ROCK3 Model C is a credit card-sized single-board computer that looks a bit like a Raspberry Pi, but with more input and output options, including an M.2 2230 slot for adding storage or a wireless network card.
The Raspberry Pi 4 is powered by Broadcom’s BCM2711 chip, while the ROCK3 Model C is powered by the 1.6 GHz Rockchip RK3566 quad-core ARM Cortex-A55 processor. The Rock3 Model C is priced from $39 (currently about $269).
The starting price applies to models with only 1GB of LPDDR4-3200 memory and no storage, and upgrading to a 2GB memory model costs an additional $5 (currently about $34). Versions with 4GB or 8GB of memory are not yet available, but are expected to be available soon.
In addition to the M.2 slot, the Radxa single-board computer has a microSD slot that can also be used for storage and supports the optional eMMC module.
The single-board computer ports include
1 x HDMI
1 x 3.5 mm audio
1 USB 2.0 OTG
1 USB 3.0 host
2 USB 2.0 hosts
1 x GbE Ethernet (with optional HAT support for Ethernet)
There is also a MIPI CSI camera connector and a MIPI DSI display connector (although the system only supports one display at a time, so it cannot be used if the HDMI port is used).
Other features include support for 24bit / 96 kHz audio, a 40-pin expansion connector, support for an optional RTC battery, and support for Wi-Fi 5 and Bluetooth 5.
Radxa says the board measures 85 x 56 mm (3.3″ x 2.2″) and works with 5V / 3A USB Type-C power supplies, but if using an SSD on a computer, a 5V / 5A power supply is recommended.