Raspberry Pi: First Impressions and Notes

I got my Raspberry Pi today, and it’s really lovely.

The first thing that struck me was how small it is – the pictures didn’t really correlate in my head, at least, to the size of the device.

I was smart enough to have pre-made my SD card, which provides its boot code as well as the filesystem containing a basic Debian Squeeze for ARM.

I’ll write up a proper post soon, but for now I wanted to share some bullet points I’ve discovered during setup:

  • You can’t really power the thing from a USB hub or computer – It needs about 700mA of power, and almost all USB sockets will provide 500mA at most, unless more is negotiated. The power port on the pi is only connected to the power rails, so can’t do that negotiation. That said, if you’re not using HDMI, aren’t really pushing the CPU and don’t have many/any USB devices attached, you’ll be fine on one.
  • With that in mind, there is a typo/mistake in the documentation from RS. One piece of paper included says you must use a 500mA max power supply, the quick start guide says it must be at least 700mA.
  • I had problems with an Ethernet cable that works fine on every other device i’ve used it on. Not sure if its a shielding issue, but swapping it out for another one worked fine. The symptoms of this including disconnections if you’re connected via. SSH, or “connection refused” error messages when you try to connect to any service.

Comments

One response to “Raspberry Pi: First Impressions and Notes”

  1. WesleyRElsberry Avatar
    WesleyRElsberry

    I bought a ‘Y’ USB cable specifically to get to the power requirement of the RasPi using a powered USB hub. The hub supply is rated to 2.5 amps, so there’s plenty for the RasPi and peripherals. I agree about the size of the RasPi unit.
     
    http://austringer.net/wp/index.php/2012/05/31/raspberry-pi-first-run/
     

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