Rock64: Cheap and rock solid // Review

It’s been a while since the Rock64 was released into the wild for hackers, but 8 months on, how good is this board looking? Let’s find out.

The back story

A lot of you will know about the original Pine64. It was a Kickstarter that launched back in December 2015. It looked like the best, cheapest SBC around, but unfortunately they ended up promising more than they could deliver.

The Pine64 guys have been steadily repairing their damaged reputation since and by the looks of their recent SBC, I reckon they’ve done a great job.

The Rock64 was released to minimal fanfare – there weren’t any outrageous claims, like “Super Computer” and they have adopted more of WYSIWYG approach.

(UPDATE: In my travels, I’ve discovered that this design may be very similar to the UNIC UC46 WiFi projector. I haven’t yet confirmed this.)

However, they’ve made it as easy as possible to get on board with this new SBC.

They have also provided a customized flashing tool based on Etcher, where you can download and burn a number of O/S images.

For tests within this video I ran several Linux distros:

What do you get?

So, what do you get for your hard earned US$25? Starting from the top right working clockwise.

  • USB3.0 host port.
  • Two USB2.0 ports.
  • GbE.
  • Audio/Visual jack.
  • HDMI out capable of 4K at 60Hz.
  • 5v/3A DC power jack.
  • IR receiver.
  • eMMC socket.
  • Reset button.
  • Flash recovery button.
  • Power button.
  • Standard Pi2 GPIO header.
  • And an additional header breaking out 12 more GPIOs and 100MbE. The first 8 pins are compatible with the Raspberry Pi P5 header.

We also have:

RK805 – is a RockChip designed PMIC that not only has 4 DC buck converters, soft start and power sequencing but an on-board RTC accessible over I2C.

RTL8211F – GbE transceiver.

SGM89000 – A stereo line driver, which has a decent Signal to Noise ratio of around 114dB.

25Q127CSIG – 128Mb SPI flash.

K4E8E324EB-EGCF – On this board, at least, 1G LPDDR3 RAM. You can also have 2G or 4G LPDDR3 RAM.

RK3288 – And lastly the RK3328, which is a 64 bit quad core SoC with frequency scaling up to 1.3GHz.

On the flip side it’s really quite boring with only an SD slot. OK… Moving on.

GPIO tests

So from the GPIO perspective what works and what doesn’t?

I had no issues with either of the I2C buses. My handy dandy, (MCP9808), temperature sensor responded OK on every O/S.

GPIOs were also accessible without issue. However, SPI was another thing altogether. In every distro, SPI wasn’t available at all. It was certainly present in the Device Tree, but there was no working kernel module.

Looking at the RK3328 datasheet, there should be 3 SPI buses. However, on the schematic, SPI2 goes directly to SPI flash and also the Pi GPIO header.

This is almost guaranteed to cause issues with some SPI devices when using the SPI flash for booting.

However, you can read the SPI flash easily via the MTD subsystem interface.