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This repository has been archived by the owner on Dec 4, 2020. It is now read-only.
Ben Nuttall edited this page Jan 17, 2019 · 5 revisions

Oddities in the script:

Python wheels

Unlike the rest, wheels for opencv, grpcio and tensorflow are compiled separately for Armv6 and Armv7. Since a) Astro Pis are Pi 1; b) Armv6 wheels work on all models; and c) we want to support students using all models, we install the Armv6 wheels knowing they will work on any model and still work when moving an SD card from Pi 1 to Pi 3 or vice-versa.

If we ran pip install for these wheels on a Pi 2/3, it would pull down the Armv7 wheels, which would then be incompatible with Pi 1, so they've been downloaded in advance. They're then copied/renamed to Armv6 and installed locally.

The rest are installed from PyPI/piwheels, but they must be installed first as some of them are dependencies of the locally installed ones.

config.txt

The following throttling options are added in Raspbian Lite only.

GPU/CPU memory split is determined by gpu_mem_512 and gpu_mem_1024 in astropiconfig.txt (which is included by config.txt). Regardless of the Pi model, the CPU is given 384MB RAM to match the Pi 1 B+ on the Astro Pi.

The Pi is throttled to use a single CPU core. The Astro Pi is obviously clocked at 700MHz, and because even with a single core, the Pi 2/3 chips are faster, it is underclocked at 600MHz to be more realistic.

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