The new Raspberry Pi Model 3 is almost identical to the Pi 2 in the board physical dimensions and mechanical construction.
The board size, the holes for the support bars, the connectors placement, including the GPIO one, are exactly the same. The only substantial change is that the two LEDs for the power supply (red) and I/O activity (green), are in different positions.
On a mechanical standpoint, therefore, Strato Pi is totally compatible with the Raspberry Pi Model 3.
The Pi3 introduces a substantial change in the serial port usage. In the Pi 3, the hardware UART of the Broadcom CPU, that used to be wired to the TXD0 and TXD1 pins of the GPIO connector, is used for the communication with the Bluetooth chipset, while the TXD0 and TXD1 outputs rely on the Mini-UART. This latter relies on the core CPU clock speed rather thank having a separate clock divider.
This may cause the baud-rate, i.e. the actual throughput of the serial port, to vary depending on the speed of the CPU core itself, making the serial port unusable. This issue has been a very debated point on the official Raspberry forum. Different solutions have been proposed to make the functionalities of the Pi 3 completely compatible with the Pi 2.
One of the first proposed solutions has been to set the CPU core speed to a fixed value, lower that the maximum one. This workaround can obviously impact the board overall performance.
Also, some “device tree” have been developed, in particular the bcm2709-rpi-2-b.dtb, disabling the WiFi and Bluetooth and connecting the hardware UART, now called PL011, with the TXD0 e RXD0 pins.
This way, the Pi 3 essentially becomes a faster Pi 2, and the full compatibility with Strato Pi is ensured.
The Pi user community is very active on this topic. We therefore expect new solutions to be developed and included in the upcoming Raspbian upgrades. As usual, it is of the outmost importance to regularly follow the existing forums. We recommend a couple of very interesting ones: