Close

Here We Go First Piece of Hardware: Vine

A project log for Agricoltura - IO

A connected control system for all agriculture applications based on RS485 control nodes and multiple wireless sensor networks

avrAVR 06/27/2020 at 03:440 Comments

Hey folks this is the first big update aside form the anouncement and rundown of the overall project. So before the page even went up I had been working out what sort of boards and subsystems I'd need to implement for this sensing network, I then began implementing these ideas and made the page once i felt things got to a certain point. The first board I started working on was Vine, well now at this point I've gotten it to the point where i want to share what I've been doing with it. 

In the first announcement I mentioned general specifications of the Vine board and mentioned that there will be multiple versions of Vine to cover all the needs in a potential system, sensing, 5V IO, and high voltage switching. I decided to implement all those features into the first Vine making it a kitchen sink kind of board, its got a little bit of everything to get started and what not. These are the new specs:

- ST Microelectronics STM32F446RET6 ARM Cortex M4F 180MHZ MCU
- 5V Tolerant Analog Inputs
- 8x I2C interfaces
- 4x UART interface (via mux)
- 8x 5V digital IO ports
- 2x G5LE-14 DC5 SPDT Relays
- USB 2.0 connectivity
- RS485 port
- 24VAC power input
- 2A 3.3V DCDC Regulator, for supporting lots of sensors
- 2A 5V DCDC Regulator, for 5V IO and other devices

The only real change form the perspective of features is losing 8 5V outputs in place of two relays for high voltage switching, but in the end this simplified the design and removed the need for a few digital components. I'm now using an IO expander that does the level conversion from 3V3 to 5V all built in, simplifying the BOM and PCB layout.  Here is the latest mockup of the design:

2D Progress in KiCAD, still need to add the relay driver circuit, but this is the mockup

3D raytracing render:

Im in the process of selecting components for the relay driver circuit and will be implementing that before the next update. The Relays and 5V IO are all being driven off the IO expander IC which will make sofware and the rest of the layout simple. Stay tuned for the next update on Vine and the rest of the family of hardware, I'm hoping to go on a design binge this weekend so expect a lot of progress. 

Lets Rock!

Discussions