After a pair of spoiled SD Cards, I've started to investigate what's happening with the SD cards and the Raspberry PI. Overlocking? Too many reads and writes?? Bad batchs?? At the current point of my investigation (2013-08-24) it seems that nobody knows, or at least all these problems can cause a SD corruption.
I've started this page to collect all my investigations and further directions.
I was using as a power source for the Raspberry PI an spare micro-usb charger. In fact, I've switched among chargers thinking that they were interchangeable. After this problem, I've made several investigations:
One thing I've discovered is this:
I've bought a new card (27-sept-2013) and started again. However, there are some changes in my configuration that worth mention. Let's see if this solve the problem or not.
The previous model was pluged directly to the power source, and I have to admit I had several blackouts. It could be the cause of the corruption??? It is not clear.
However, with this new model, I've installed also a blackout detector that sends me a message when the house is out of power and also, after 25 minutes, shuts the Raspberry Pi down, so I think possible problems related with power are removed from the equation.
I've bought a 1A (1000 mA) power source with 5V output. Ok, let's be true: it was sold in the supermarket as “charger”, but it cost 15 euros instead of the usual 5 euros a cheap one usually costs.
I've measured it and it's regulated: it gives 5V despite of the consumption of the device, or (I guess) the power source of the house.
You can get one of this from farnell, but the problem with farnell is that you have to spend at least 25 bucks per shipment.
After this, the board is running well, but it's too early to reach conclusions; lets give it some time.
The unit is powered via the microUSB connector (only the power pins are connected, so it will not transfer data over this connection). A standard modern phone charger with a microUSB connector will do, providing it can supply at least 700mA at +5Vdc. Check your power supply's ratings carefully. Suitable mains adaptors will be available from the RPi Shop and are recommended if you are unsure what to use.