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…
This is a 3D of my Sensor IO Hat Rev 1.0 that allow interfacing to 8 x Analogue/Digital sensors, 3 x I2C and 3 x SPI. STM32F405 have 16 x 12 bit ADC channels and each AD port have 2 IO pins that can be used . The Sensor IO Hat is about connecting to…
The most obvious Hat to use HLK-7688A on is a Ethernet Switch or Router with SPI backbone support. I have ordered a dev unit so I can test out this possibility. The Ethernet switch part is very straight forward, I also see a very decent SPI, but I need to dig a bit more into…
First attempt on block diagram for the 3D Sensor Hat. The main components are FXOS8700 (Accelerometer and Magnetometer), FXAS21002 (Gyroscope), NEO 6/7/8 (GPS) and BME280 (Temperature, Humidity and Pressure). I am also attempting a TFT connection here, but this is secondary and can be ditched if needed. The rest is classic – Raspberry PI/SPI on…
Final 3D of the Sensor Hat. The most noticeable here is that I start using the 2×5 pin SWD header. The rest is as described before. MCU STM32F405RG 1 x High Speed SPI for backbone Raspberry PI Hat format 1 x CAN for control bus. 8 x 2 x Analogue/Digital IO Signals. 3 x I2C…
Just added the package for CR1220. The actual package look at bit different, but this has the correct footprint and size. This looks like a large component, but it is not – it is more an indication of how small and dense these Hat’s are. I will attempt to update the next revision of XPortHub…
I have still not routed this, but schematics and component location is getting in place. I have to make a package for CR1220 battery holder for RTC + I would like to make the proper packages for the connectors as well. I dropped the extra CAN and RS485 due to lack of space + I…
This little circuit show the passive protection I want to add to each analogue and digital line. D1 is a TVS diode set to ca 5V, meaning it will suppress spikes above this level or negative spikes. This is the real light-weight protection. The drawbacks with a TVS is that it takes time to activate…
An early mockup indicate I can manage 15 connector on a Hat with USB, but I will have to remove the external power connector and one of the connectors are CAN1, meaning the actual number of sensors are 14 connectors. If I dropped I2C and SPI I could just about manage 16 Analogue/Digital sensors, but…
Some sensors like 3D sensors are suited to be mounted directly on a Hat, but a majority of sensors actually need to be mounted remotely to provide proper input. To interface to these I need an adapter card with connectors as illustrated above. STM32F405 have 16 ADC inputs that also can be used as GPIO…