Adam ADE Pro + board...

[MrPix]

I've been doing some basic work on my single board ADE Pro "Plus" implementation. ADAMnet comes in, is buffered, then passed to the ATmega2560 microcontroller. The signals are then passed on two four internal expansion ports in the enclosure. These will be for future expansions, and anything people hand me a schematic for, I will develop to fit in the same single enclosure. More on that below.

 

On the front will be a display - 1602 if my arm is twisted, but otherwise a nice OLED or TFT display, and the usual buttons.

 

I have temporarily provisioned two SD slots, because it would be easy to adapt the ADE code to support two drives. This would make copying files much easier, and remove the need to do it on a PC. However, if the ADE author opts to not implement that I can simply make the second slot a microSD slot, so adaptors are not required.

 

The whole thing would go in a custom colored and printed case to 100% match the Adam.

 

So, extra interface cards. The first I have in mind is a PS/2-USB keyboard card. Adam keyboards are in short supply and getting super expensive, so it might be nice to be able to use a nice tactile PC keyboard. PS/2 is much easier to implement than USB, but both are possible. It's just a matter of forking the ADE code, which already contains a full ADAMnet stack.

As always, these designs would be fully open source.

 

Below is a basic concept board, so I can work out desirable case dimensions, case height, etc.

 

Feedback/questions invited.

Edited February 13, 2020 by MrPix

[MrPix]

My target price for this complete unit is at most $80-90, including shipping and SD card. I am hoping for less, though.

 

The expansion cards can be 2.2" wide by 2.6" high, with RA pins in two groups of three. Cards will have end gaskets (like PCI cards) to accomodate connectors, etc. The gaskets will be 0.49" wide by 2.85" high. The expansion backplane is in pairs, so H1/H5, H2/H6, etc.

 

H1.1: ADAMnet

H1.2: GND

H1.3: /RESET

H5.1: +5V

H5.2: GND

H5.3: 3V3

 

ADAMnet will be buffered, and 5V and 3V3 will be provided by an external power source, included.

[MrPix]

I tried getting two SD slot support added by the code developer, but they declined. Instead, I am going to create a generic ADAMnet backplane, and make sure the software can support two Adamnet devices side by side.

 

The main need for the powered backplane is to create a powered hub for ADAMnet devices. Only about 500mA is available on the 5V supply, and the keyboard uses about 350-400mA. Or at least, on of my keyboards draws 355mA and one draws 397-8 mA. Part of this is the clunky old 6801, but the other element is loss from both rows and columns of the membrane being pulled up through 22K. 21 22K pull-ups add up. If I were to redesign the keyboard I'd use diodes on the wider side. If the 6801 were replaced by a modest Arduino, clocked slow, that 350-400mA could be reduced to maybe 120-150mA, leaving 350-380mA available for a couple of devices.