Posted March 14, 2018
In honor of Pi Day, I figure I would mention a few facts about the Raspberry Pi series of computers that people might not know about. Note that this post is not an introduction to what the Raspberry Pi is, but rather is a discussion of certain things you might not know about.
Version differences:
There exist different versions of some of the Raspberry Pi boards, even with the same number and model. Those differences are likely to be minor, but there are exceptions:
* Pi Zero: Version 1.3 has a port for the Raspberry Pi Camera Module.
* Pi 2: There's a rather significant difference; version 1.;2 actually uses a different chip than earlier models. Instead of the BCM2836 like the earlier Pi 2 versions, it has a BCM2837, like in the Pi 3. This means that version 1.2 of the Pi 2 can run 64-bit code; it is basically a Pi 3 without the wireless or bluetooth, and with an underclocked CPU.
Pi 1 model B: Originally, these had only 256MB of RAM, but at one point they upped the RAM to 512MB. (The model A has only 256MB, but why get that when you can get the model A+ for the same price?)
Other ways to boot the Pi:
It turns out that some Pi models can be booted without an SD card inserted. In particular:
* Pi 0 and 0W can be booted as a USB device. Connect the Pi to a computer with a USB cable, and it will appear as a USB device. You can then use the rpiboot program to boot the Pi. (One use of this is to turn the Pi into a microSD card reader, meaning that you don't need a separate card reader to install the OS or fix it if it stops booting.)
* Pi 3 (and likely Pi 2 version 1.2) can boot via USB (as a host), but you need to make an irreversible change to do this. They can also boot via wired Ethernet.
It's also worth noting that the Pi 0 and 0W can function as USB devices, if you have the right device tree overlay and kernel modules enabled.
Version differences:
There exist different versions of some of the Raspberry Pi boards, even with the same number and model. Those differences are likely to be minor, but there are exceptions:
* Pi Zero: Version 1.3 has a port for the Raspberry Pi Camera Module.
* Pi 2: There's a rather significant difference; version 1.;2 actually uses a different chip than earlier models. Instead of the BCM2836 like the earlier Pi 2 versions, it has a BCM2837, like in the Pi 3. This means that version 1.2 of the Pi 2 can run 64-bit code; it is basically a Pi 3 without the wireless or bluetooth, and with an underclocked CPU.
Pi 1 model B: Originally, these had only 256MB of RAM, but at one point they upped the RAM to 512MB. (The model A has only 256MB, but why get that when you can get the model A+ for the same price?)
Other ways to boot the Pi:
It turns out that some Pi models can be booted without an SD card inserted. In particular:
* Pi 0 and 0W can be booted as a USB device. Connect the Pi to a computer with a USB cable, and it will appear as a USB device. You can then use the rpiboot program to boot the Pi. (One use of this is to turn the Pi into a microSD card reader, meaning that you don't need a separate card reader to install the OS or fix it if it stops booting.)
* Pi 3 (and likely Pi 2 version 1.2) can boot via USB (as a host), but you need to make an irreversible change to do this. They can also boot via wired Ethernet.
It's also worth noting that the Pi 0 and 0W can function as USB devices, if you have the right device tree overlay and kernel modules enabled.
