Tech Review – Rock Pi S

by @edent | # # # | Read ~103 times.

The good folk at Seeed Studio have sent me a Rock Pi S to review. Since the original Raspberry Pi came out, there has been an explosion in Single Board Computers – but this one is special.

Various photos of a tiny computer.

It is miniscule – almost dominated by the Ethernet port. And the specifications are ridiculously good – considering this thing costs US$10 + postage.

  • 256MB RAM
  • USB-C power
  • Ethernet
  • 26 GPIO pins
  • Another 26 pins for voice/audio (I2C, PCM, TDM, PDM, SPDIF, and HDMI ARC)
  • And, of course, it runs Ubuntu!

Quickstart

Head over to the download page and grab either Debian or Ubuntu. Follow the guide to burn the OS to a micro SD card.

Shove the card in the Pi, and attach the board to your computer using a USB-C cable. Here comes the clever bit!

The OS responds to adb (Android Debug Bridge) commands.

adb shell connects to the Rock Pi.
/bin/bash starts the regular shell.

By default, a “heartbeat” LED blinks.

Disable it with the following command:

echo none > /sys/class/leds/rockpis\:blue\:user/trigger

OK. Now what?

Connect to the Internet

The higher spec versions have WiFi and Bluetooth. If you want them on this version, you’ll need to plug them in to the USB port. Or, shove an ethernet cable in it. Once connected, the date automagically updates and you can upgrade the OS with

sudo apt update
sudo apt upgrade

SSH is enabled on the device, if you don’t want to use ADB. The default username / password is rock.

Music

The board is pretty well optimised for audio work.

As a test, I ran an example .wav through the Opus encoder, on a ridiculous quality setting.

Encoding using libopus 1.1.2 (audio)
-----------------------------------------------------
   Input: 48kHz 2 channels
  Output: 2 channels (2 coupled)
          20ms packets, 512kbit/sec VBR
 Preskip: 312

Encoding complete                                
-----------------------------------------------------
       Encoded: 1 minute and 30.82 seconds
       Runtime: 13 seconds
                (6.986x realtime)
         Wrote: 5647048 bytes, 4541 packets, 100 pages
       Bitrate: 494.968kbit/s (without overhead)
 Instant rates: 121.6kbit/s to 510.4kbit/s
                (304 to 1276 bytes per packet)
      Overhead: 0.494% (container+metadata)

Good enough! Decoding back to .wav from .opus took 6 seconds.

The arm64 version of ffmpeg is also available. It was similarly quick at decoding AC3 and DTS audio.

Conclusion

Obviously, everyone wants to know how this compares to the Raspberry Pi.

Pros

Cheap! Tiny! And USB-C. Everything I love in a device.

The audio support is magnificent.

Cons

Lack of community. There’s excellent documentation, but the forum is sparsely populated. There are lots of enthusiasts, but I worry that’s not enough to sustain interest.

It is audio only – no HDMI for video output.

Buy it!

Buy the Rock Pi S from Seeed Studio.

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