I decided to change XPortHub2 due to parts of the layout – I need to use SPI 1 for “Device Bus” due to speed on F405, but the paths was crossed with Ethernet SPI and USB, meaning I had high frequency signals close without any isolation. I decided to re-route that part and add the…
This is the block diagram for XPortHub2 with an added Watchdog/D-bus. My objective here is that I want to add some features to the board and decided to do an experiment adding an external Watchdog/D-Bus by using a smaller STM32 in support. SPX3819 can be switched on/off enabling me to power a board on/off. Adding…
3D model of XPortHub2. This contains an 10/100Mbps Ethernet with a standard RJ45 socket that replace TF Card, I2C and SPI on XPortHub1. New style SWD port. Raspberry PI Backbone with SPI and CAN. RTC with Battery holder on back. 8 x user leds. 2 x CAN ports. CAN1 is connected on Raspberry PI Connector…
This pic is from the new XPortHub2 with Ethernet via W5500. The routing is close to being a single layer. The total number of passive components makes this occupy 1/3 of the board. The only challenge here is that HR911105A is a bit to tall for the next board in the stack – this…
I am not sure where I wanna use this W5500 circuit, but the nice thing is that KiKad makes this a module I can re-use. This actually is the reference schematics.
Adding the USB console with a buffer so I can perform printf before the console is open was very usefully as I instantly detect that it’s huge differences between starting the device from the IDE on debug mode or on its own. These things are a bit annoying, but they can be handled if your…
Kind of cool – using USB as console on XPortHub – notice all the init messages before the USB starts. Just a buffer tricks. The “Terminal” is a simple C# app that open a port, read/write. I will upgrade it to a proper CLI later. This is maybe the most important part of the infrastructure…
This drawing is an overview of the Hat’s in progress. A few is only on the planning stage, but most electronics is on prototype level and SW is coming on. Raspberry PI is the obvious core if I need heavier processing. Due to the nature of it’s SPI I can only connect one of these…
This illustrates the BasicPI Firmware Stack in progress. What I always do in embedded applications is to make a “standard” main.cpp as follows: void AppInit() { // wire hardware } int main() { AppInit(); // start OS } A team I worked in years ago agreed on this standard so we should…
CAN CAN RS485 RS485 Terminal switch for CAN & RS485 USB Micro SD Card SPI Flash RTC Battery Power connector I2C SPI TTL UART RS232 RS232 Raspberry PI Connector STM32F405RG SWD Connector Changes from Rev 1.0 1 Corrected wrong SPI Flash package 2 Added resistors to SPI 1 to support Half-Duplex SPI 3 Replaced…