I was designed new boards on ATmega2560-16au and ATmega128A in small size and have the all pins:
1. experimental board (home making) for ATmega128A size 56x72mm:
2. experimental board (such home maked) for ATmega2560 size 56x72mm:
And maked for it boards expansion SRAM up to 512 kbytes with 3 addresses window. Now testing this boards and have manufactured plates by China (gerbers is my own) for 3 plates:
Now maked the board.txt file whoes can adding special link compiler file into Arduino IDE and enabled use the all SRAM into sketches for declare arrays and othe data in upper SRAM.
This is a present in the "first" and "second" editions for all pins boards:
"first" - DC-DC by AMS117-5.0 on board;
"second" - on boards mounted DC-DC with RT8289 chip having 5v with 5A.
And now, are making into kicad the "third" release 64x96mm such this:
What kind of board is letter?
The third board has own size 64x96mm and have:
1. Simple details for light-doides 3mm, DC-DC converter on low-cost details condensers, diodes, coil - this demand more space;
2. Pins on the sides:
up (left to right) : ADC 0..15 with AREF. Each pin road has ground roads up to chip Mega2560. Right block: PCint9..15 that no present on the traditional Mega board and UART3, UART1;
left (down to up): I2C x 2 pin, SPI pins, Vin, Reset, UART0, UART2.
down (left to right): Timer1, Timer0, Timer2, Timer3, Timer4, Timer5 pins only.
right: has only expansion SRAM interface with additional pins from address-latch register (on board too) A0..A7. In this interface you may connect small expansion SRAM directly.
The third board has claim measure 64x96mm and have:
1. Basic subtleties for light-doides 3mm, DC-DC converter on ease subtleties condensers, diodes, curl - this interest more space;
2. Sticks on the sides:
up (left to right) : ADC zero..15 with AREF.
Each stick street has ground streets up to chip Mega2560. Right square: PCint9..15 that no present on the customary Uber board and UART3, UART1;
left (down to up): I2C x 2 stick, SPI pins, Vin, Reset, UART0, UART2.
down (left to right): Timer1, Timer0, Timer2, Timer3, Timer4, Timer5 sticks as it were.
right: has just development SRAM interface with extra sticks from location lock enroll (on board as well) A0..A7. In this interface you may associate little development SRAM straightforwardly.