Rockchip RK3308 is a quad-core Cortex-A35 processor that was announced in 2018 together with RK3326 specifically for Smart AI solutions. While the processor is equipped with an RGB LCD output interface, it does not come with a 2D or 3D graphics accelerator, so it’s better suited to smart speakers with an optional display using a basic user interface.
I’ve not seen many hardware platforms or boards based on the processor, but today I noticed “Hangzhou Wild Chip Tech” had an RK3308 system-on-module, as well as development kits for sale on Aliexpress with the module price starting at $23.
- SoC – Rockchip RK3308 quad-core Cortex-A35 processor @ 1.3 GHz with NEON and VFPv4 FPU
- System memory / storage configurations:
- 256MB DDR3/3L + 256MB NAND flash
- 512MB DDR3/3L + 8GB eMMC flash
- 2x 100-pin dual row headers (1.27mm pitch) exposing:
- Display – LCD interface up to 1024×600 (RGB), up to 1280×720 (LVDS)
- Networking – 10/100M Ethernet (apparently multiplexed with the LCD interface)
- Audio – I2S, PDM, TDM, PCM, microphone inputs, S/PDIF, speaker outputs, LINE out, headphone out,
- USB – USB OTG+Host
- GPIO’s, 5x UART, 3x SPI, 4x I2C
- SDIO 3.0 for WiFi/Bt module
- ADC input and ADC temperature sensor
- Power signals
- Power Supply – 5V DC input; RK816-3 PMU with support for battery charging
- Dimensions – 65 x 45 mm (6-layer PCB)
The company apparently provides documentation with a user manual, schematics, and datasheets as well as Qt 4.8.7 demos, a Linux 4.14 image, a Linux BSP based on Rockchip BSP, as well as host computer drivers for the board. Some of which are available on Mcuzone’s downloads page. Although everything looks to be in Chinese, some documentation like RK3308 technical reference manual is in English.
The company is also offering a complete development kit for the module with MDK3308-EK baseboard, and optional accessories such as a 4G modem (EC20), a USB UVC camera, or a 7″ touch screen display.
- SoM Support – Socket for “MDK3308 Coreboard” RK3308 system-on-module described above
- Storage – SD card slot
- Display I/F – RGB666 LCD FPC connector with 0.5mm pitch
- Connectivity – 10/100 Mbps Ethernet (RJ45); dual-band 802.11b/g/n/ac WiFI 5 and Bluetooth 4.1 via Ampak AP6255 wireless module + u.FL WiFi antenna
- Audio – 6x MIC analog microphone array
- USB – 3x USB hosts via USB hub controller, USB OTG interface via 1x micro USB or USB-A port
- Serial – 3x 4-pin TTL UART header with 2mm pitch
- Sensor – LM75A I2C temperature sensor
- Debugging – Micro USB serial console via CH340G USB to UART chip; TTL debug port
- Misc – 5x LED including 3x PWM, 1x heartbeat, 1x power; debug port jumper; 5x ADC user buttons; reset button
- Power Supply – 5V/2A via power barrel jack; 2-pin header for Lithium battery
- Dimensions – 180 x 130 mm
The full MDK3308-EK evaluation kit includes the RK3308 CoreBoard, the baseboard with WiFi antenna, a micro USB cable, and a power supply.
MDK3308 Coreboard price starts at $23 with 256MB RAM and 256MB NAND flash, $26 with 512MB RAM, and 8GB eMMC flash. The MDK3308-EK evaluation kit sells for $69.99, but you can also select other bundles with the C70 display for $109, a USB UVC camera for $89.99, or a 4G modem for $99.99.