XMEGA PiLoT

Go To Last Post
3 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

First, thanks to all contributors for a brilliant forum. I've found answers to questions here many times over the years.

 

I'm working on some hardware and software for building control / home automation. The hardware is mainly based on Xmega MCUs, so far I've used the 64D4, the 64A4 and am about to use a 32E5. The core of the work is an RS485 bus for comms between sensors/actuators and a "bridge" to a wired ethernet LAN. It makes it simple to create a sensor/actuator device which communicates with a LAN connected controller; the device hardware and software needs only to deal with the (simple) RS485 side of things, and can therefore be designed quickly and easily. As an aside, I do the bridging with a Wiznet Wiz850io module (based on their W5500 SPI-ethernet chip); getting this working was an interesting journey of discovery with both standard and USART SPI controllers, and also the DMA controllers in the Xmega A (the USART does SPI mastering faster, and the DMA controllers didn't help). 

 

So... I have found myself wishing there was an Xmega counterpart of the Arduino Mega - or something like it - for rapid prototyping. My question is: how useful would a Raspberry Pi form factor dev board with an Xmega be to you all? The Pi ecosystem is 3.3V friendly so it seems a better fit than the Arduino.

 

I'm thinking of designing 2 versions:

 

1) Pi model B+ format

  • (say) Xmega 128A3U MCU 
  • Pi compatible 3.3V GPIO header, with auxilliary header for ADC/DAC signals
  • Wiznet W5500 SPI-ethernet chip with RJ45 magjack for LAN connectivity
  • micro USB for power in during development, with data lines connected to USB signals for 'U' variants of the Xmega
  • optional DC-DC converter for 7-24V DC in
  • optional xtal
  • optional RTC

 

2) Pi model A format

  • as above, but physically smaller and without ethernet

 

The "PiLoT" name means "Pi form factor, LAN of Things"...

 

Grateful for any thoughts and suggestions. If I do design these things, I'll publish the result under some sort of free/open licence.

Last Edited: Wed. Jan 25, 2017 - 06:13 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

Rather than go to the trouble of designing a whole new prototyping platform, why not just use an Xplained Pro? There are many different Add-on modules that are  designed to simply plug into the extension headers which the Xplained Pro will recognize and work with. For example you could use this Xplained Pro combined with this Add-on board for RS-485. You can see a full list of Xplained Pro and Add-on boards that Atmel have designed here, but there might well be many others you can get hold of that other people and/ or companies have made. 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

amb5l wrote:
... I do the bridging with a Wiznet Wiz850io module (based on their W5500 SPI-ethernet chip); ...
That's similar for one of the Alvidi XMEGA boards (instead a W5200) :

http://alvidi.de/products/EN/AVR_Development_Boards/avr_board_xavrb_ext.php

amb5l wrote:
I have found myself wishing there was an Xmega counterpart of the Arduino Mega - or something like it - for rapid prototyping.
An XMEGA32A4 on an Arduino Uno factor :

Akafuino X

amb5l wrote:
... how useful would a Raspberry Pi form factor dev board with an Xmega be to you all?
Would prefer BeagleBone Capes instead of Pi HATs due to :

  • Slightly less area
  • Greater strength (opposing inline connectors)
  • Greater quantity of signals
  • BeagleBone Black Industrial (-40C to 85C)

http://www.newark.com/element14/bbone-black-ind-4g/beaglebone-black-rev-c-cortex/dp/53Y3717

amb5l wrote:
(say) Xmega 128A3U MCU
or an XMEGA128A1U for more signals though an XMEGA256A3U would be a better match for a Pi HAT with more program and data space

amb5l wrote:
optional DC-DC converter for 7-24V DC in
Increase to 30Vdc to match a charged 24V SLA battery (recreational vehicles, semi-tractors, buses, medium trucks)

amb5l wrote:
optional xtal
A third pad would open up resonators, and, adding a "common" oscillator footprint would allow temperature compensation, MEMS, etc

amb5l wrote:
optional RTC

  • Is there a common footprint for RTC? (reason : multiple manufacturers)
  • XMEGA256A3BU has a RTC

P.S.

amb5l wrote:
The core of the work is an RS485 bus for comms between sensors/actuators and a "bridge" to a wired ethernet LAN.
A way to bridge UART to LAN or WAN is by an embedded Linux board via a websocket server :

https://github.com/chilipeppr/serial-port-json-server

Serial Port JSON Server is a websocket server for your serial devices. It compiles to a binary for Windows, Mac, Linux, Raspberry Pi, or BeagleBone Black that lets you communicate with your serial port from a web application. This enables web apps to be written that can communicate with your local serial device such as an Arduino, CNC controller…

P.P.S.

Alternate ways :

  • Atmel Xplained Pro (only one XMEGA in the Xplained Pro series)
  • Competitor

http://busboard.com/images/products/BPS-KIT-BB2-F3-F4_Connected.jpg

via

http://busboard.com/KIT-BB2-F3-F4

 


http://schmartboard.com/content/Mechanical/schmartboard_pd_710-0010-01_dim.pdf (Pi HAT protoboard)

via

http://schmartboard.com/raspberry-pi-through-hole-prototyping-add-on-board-bare-board-only-710-0010-01/

http://schmartboard.com/content/Mechanical/schmartboard_pd_205-0001-01_dim.pdf (BeagleBone Cape protoboard)

via

http://schmartboard.com/beaglebone-through-hole-prototyping-cape-board-only-205-0001-01/

https://www.websocket.org/index.html

 

Edit : industrial BeagleBone

 

"Dare to be naïve." - Buckminster Fuller

Last Edited: Wed. Jan 25, 2017 - 08:37 PM