PocketBeagle: Linux and lots of I/O pins for 25 dollars
Summary
Ken Shirriff examines the PocketBeagle and shows how much Linux, real-time I/O and expandability fit on a tiny board. The PocketBeagle measures about 56 by 35 millimetres. Its Sitara AM3358 runs at up to one gigahertz.
Ideas
- The AM3358 processor combines an ARM core with two programmable real-time units.
- The PRUs control time-critical pins independently of the Linux scheduler.
- Two pin headers bring out numerous signals for your own hardware.
- Leaving out Ethernet and HDMI keeps size, price and power consumption low.
Insights
- Deterministic coprocessors turn a small Linux computer into a precise controller.
- Open pin assignments shorten the path from prototype to your own board.
- Hardware choice should weight interfaces and real-time requirements more than computing power.
Facts
- At release the board cost about 25 US dollars.
Recommendations
- Plan level shifters and power supply before connecting your own hardware.
- Use PRUs for hard timing requirements instead of time-critical shell scripts.
References
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