by Alex Eames - RasPi.TV
@Craig Thanks for mentioning that. Yes that is correct if you're using 14/15 as UART. But if you're using 14/15 as GPIO (rather than alt function Tx/Rx) that issue becomes irrelevant. So it really only affects advanced users who will solder on a header and connect via the direct Tx/Rx connections.
I believe it was just discovered that there are changes to the GPIO pins on the Pi3. From the FAQ:
"My GPIO-connected UART device is broken on Pi 3, why?
The mini-uart is now routed to GPIO14/15 as the PL011 UART is now used for bluetooth communications. The mini-uart doesn't have a separate clock divisor and uses the core clock frequency. Changes in core clock (e.g. through throttling or idle/load frequency changes) will result in arbitrary modification of the effective baud rate. "
You can see some workarounds, but even these GPIO reassignments will cause other issues and/or loss of functionality. See this blog for full details on the issue and workarounds: http://www.briandorey.com/post/Raspberry-Pi-3-UART-Overlay-Workaround
Hi Sami it's really simple and I have published the basics in the FAQ...
How does the port protection work?
It uses a 330R resistor in series with each port to limit current to 10 mA per port. A 3V3 Zener diode 'clips' any over-voltage and diverts the excess to GND. It also protects against small negative voltage (~-1V)
...but I doubt it would help you very much at 5000V. It's designed to protect against someone accidentally wiring 5V (or maybe 12V) up to a GPIO pin. It's not for seriously High voltage protection. Yes I do plan a blog about this at some point, but it won't be very soon.
Can you please soon explain/describe how the hat can protect Raspberries. You once claimed that the hat saved your RB2b and said you would explain that later thoroughly. However, I have not seen any convincing explanation.
It would be very nice to get some designs about the isolation. How many layers and where isolations etc? I would like to understand how the hat could improve the isolation of the raspberry. I am interested in the fact because I am using my own hats where I have protected the raspberry from exterior by ADUMs1000 which lasts one minute at 5000 V. It would be nice to understand how the hat could interfere my designs. I would like to see how the hat can better isolate the raspberry from the transformer.