Category: Embedded Development

Smart SPI Schemes

SPI is a very powerfully and fast serial port used between Master and one or more slaves, but I want to evolve the bus into a proper device to device bus. This is actually far more straight forward than I expected as both Raspberry PI and STM32F405 support Half-Duplex modes. RPI only support Half-Duplex Master,…

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Upgraded LoRa Options

I finished the LoRa + GPS w/E22-900M30S earlier today and decided to add in E22-900M22S footprint. The modules are almost identical except in size. The only difference is that 30S have pin 10 to 3.3V while 22S have this to ground, so it is straight forward to have both footprints on the PCB. The 3D…

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LoRa/GPS Hat Annotated

IPX Antenna for LoRa directly on the module. PCB Antenna for LoRa. Power leds + MCU Status. USB Connector for MCU. Separate Power connector. GPS Module. Can use NEO-6M, NEO-7M or NEO-8M. GPS Antenna. USB for GPS Module. UART TTL. SWD STM32F405RG. Powerfully ARM M4 capable of running MicroPython. Raspberry PI Connector. CAN Port. LoRa…

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NEO-6M GPS Hat

This is a LoRa and GPS Hat. The larger E22-900M30S with a range of 12km at left and the small NEO-6M at right. NEO-7M and NEO-8M should also work. I mistook NEO-6M for having a SPI interface, but realized this was for Flash/EEPROM. I replaced coils normally used to separate frequency interference with 3 x…

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60V DC/DC Hat

I decided to add the Hat form and RPI connection to my Hat allowing me to use this as a PSU as well. I need far more powerfully PSU’s than this, but TPS54260 can deliver 2.5A on any voltage I need, so it’s a beginning + its 3 voltages coming from this board so why…

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4G/NB-IoT Hat

SIM7020E is a small module that offer 4G services and access to the new NB-IoT service that is available to give access to remote sensors that earlier was not possible. All-in-All this is just a new wrapping on a service that have been available since GSM and can be achieved with several low cost modules.…

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