Just thought I would share the project I am currently working on.
This is "The Brick", a All-In-One board which features a AtMega2560 and 3 AtTiny84's, with the following I/O.
18 General Purpose IO, PTC Fused with Zeners, capable of handling up to 30VDC inputs
12 Digital Outputs, which you can select for 5V or 24V output, capable of being PWM'ed, (3x L293D chips).
6 Relay Outputs (30VDC @ 10A, 240VAC @ 10A - Resistive Load, or 28VDC @ 5A, 120VAC @ 5A - Inductive Load)
8 Single Ended Analog Inputs
12 bit 16 Bit (Selectable from 0-5V or 0-10V) or 4 Diffrential Inputs (Selectable input ranges within 0-5V or 0-10V) ( MCP3208 ADS1115)
4 Analog Outputs, 8 Bit 12 Bit (0-10V) (MCP4728)
3 High Speed Inputs capable of handling up to 30VDC inputs (These are the 3 seperate AtTiny84's, talking to the AtMega2560 over SPI)
USB Programming and Serial port like the Arduino (UART0)
RS232 Comms (UART1)
RS485 Comms (UART2) - With Power on the socket to supply slave boards (fed from Adjustable Supply, mentioned below)
It supports either Bluetooth (Sena Bluetooth Module) or XBee Module for wireless comms (UART3)
Real Time Clock (DS3231S)
External EEPROM (24LC256)
Micro SD Card Flip-Lid Socket
5VDC Switchmode power supply on board, capable of 2-3A (LM2596S-5.0) Adjustable Switchmode power supply, designed with 24VDC in mind however adjustable from 10V to 24V, capable of 2-3A also. (LM2596S-ADJ)
Here is a picture of the PCB:
Here is a rendered picture of the PCB is the case, top removed:
Here is a rendered picture of the case closed up, back view:
I am just finalising it at the moment and hope to get the first prototypes ordered this week.