On any Raspberry Pi Model B/B+, the OTGID pin is driven to 0 and therefore will only boot via host mode once enabled (it is not possible to boot through device mode because the LAN951x device is in the way).

The Raspberry Pi 4 Model B (Pi4B) is the first of a new generation of Raspberry Pi computers supporting more RAM and with significantly enhanced CPU, GPU and I/O performance in a similar form factor, power envelope and cost as the previous generation Raspberry Pi 3B+.

The GPIO header has grown to 40 pins, while retaining the same pinout for the first 26 pins as the Model A and B. More USB ports. It comes with 4 USB 2.0 ports, compared to 2 on the Model B, and better hotplug and overcurrent behaviour.

Raspberry Pi 4 Model B product brief; Raspberry Pi 4 Model B schematic diagrams; Raspberry Pi 4 Model B mechanical drawing; Documentation including hardware and configuration

Raspberry Pi 3 Model B+ has a 64-bit quad-core processor running at 1.4GHz, dual-band 2.4GHz and 5GHz wireless LAN, Bluetooth 4.2/BLE, Gigabit Ethernet over USB 2.0, and PoE capability via a separate PoE HAT.

Raspberry Pi 4 Model B features a high-performance 64-bit quad-core processor, dual-display support at resolutions up to 4K via a pair of micro HDMI ports, hardware video decode at up to 4Kp60, up to 8GB of RAM, dual-band 2.4/5.0 GHz wireless LAN,

2018年6月20日 · Re: Weird problem with GPIO in/out in RASP PI Zero and model B. Wed Jun 20, 2018 12:27 pm

2017年10月4日 · Re: Adding a 5V Fan to a Raspberry Pi 3 Model B and having control of it Tue Dec 19, 2017 12:03 pm Using my original diagram to connect your fan you can control the fan speed using PWM.

2012年10月22日 · We are pleased to announce that schematics for the revision 2.0 Raspberry Pi Model B are now available here. This post describes the key changes introduced in the new board revision.

2013年3月4日 · Could someone tell me the pinouts of the Model B headphone jack (the light blue jack)? (Or pads D5-D10 that the jack connects to on the board.) Thanks!