Wednesday, 3 July 2013

The new mini biggie

First build of my Mini-web board.
It has:
ATMEGA1284 (2 serial ports, 16K ram, lots of other goodies....)
DS1307 battery-backed clock
micro SD card
Ethernet (WIZ820 module)
Radio socket-strip (for nRF24L01 or other)
Breadboard friendly
Atmel 6-pin ICP header

Initial testing with Arduino software, programming by AVRISP MkII.
Ethernet, RTC, SD and radio all tested. 
Soon, I'll put an Arduino bootloader on and try serial programming. It should work with a FDTI basic, using DTR to reset. The resistor/cap are in place on the reset line and the DTR has a pin of the board-edge.
The required TX/RX/DTR/+V/GND are not all together as per the Arduino standard but a small wire harness will hook it up OK.
Serial programming was an afterthought, I use the ICP header for all my stuff.

Its a layered construction. The SD socket is under the Ethernet connector

The white connector is the RS485.
6-pin ICP is on the closest corner

Bottom of PCB, battery holder not yet present.

Top without the WIZ820 module.
SD socket is between the mounts for the Wiznet module.

From left to right, 1st 8-pin SM chip is the RS485 driver, next one is the DS1307 RTC

Socket strip on the right-edge is for a radio.
This can be a sparkfun nRF24L01 breakout, or a RFM12 breakout, or a RFM70/73 breakout.

And a Sparkfun radio board plugged in.

So, 2.4Ghz link, 128K flash, 16K ram, RTC, micro-SD slot, Wiz820 ethernet and RS485 on the 2nd serial port.

I suppose I'd better learn to program it now.....