Raspberry Pi 2 Model B Update: Xenon Flash Related Failures

I’m still waiting on my Pi to arrive, but I came across this great video by Dave over at EEVblog that covers a very interesting problem with the new Pi’s.

The trouble is that when exposed to light from a xenon flash (typical camera flash), the Pi shuts down and requires a hard reset to come back up.

This problem is caused by the photoelectric effect, which allows things like image sensors to work. Based on Dave’s experiments, it seems that the problem is from a voltage regulator chip with an exposed die. The exposed die appears to allow the photoelectric effect to cause the regulator to drop out just long enough for the system to fail.

Raspberry Pi 2 Model B Preview

These were announced last week, and I can’t wait to get my hands on one. The Raspberry Pi finally got a major upgrade. It’s actually a real computer now, and the best part is that the price hasn’t increased.

At a glance, the Raspberry Pi 2 Model B appears to have carried over the layout from the B+. It retains all the same external connections in the same locations.

Where this model gets its major upgrade is at the core. The chipset has been upgraded from a single core ARMv6 to a quad core ARMv7. The RAM has been boosted from 512 MB to 1 GB. It is no longer in the chip, and is now located on the back of the board.

It looks like most Pi HATs that were designed for the Raspberry Pi B+ should work with the model 2, since the layout and header haven’t changed.

If you plan on upgrading from an older board, the SD card will need to be updated for the new processor. You can either update your existing system before swapping the card, or just flash it with a new image.

One other noteworthy change is the power requirement. The maximum rated power draw of the Model 2 is 900 mA, over the 600 mA of the B+. This means that it really should be running on a dedicated power supply capable of delivering at least 1 amp, even though it is still powered by the MicroUSB connector.

All these upgrades actually make the Pi competitive with the Beagle Bone Black. Here are some numbers I compiled from a couple benchmarks (1, 2) over at Adafruit:

nbench Scores RasPi 2 (900 mHz) BBB RasPi 2 (950 mHz)
Memory Index 4.228 5.661 4.359
Integer Index 5.607 6.032 6.341
Floating Point Index 4.769 1.591 5.037

As you can see, the Pi’s floating point numbers come out well above the BeagleBone’s. That alone doesn’t make this a BeagleBone killer since the BeagleBone still has lots of features that make it stand out, but the Pi just became a much closer competitor.