Micro Engineering Board

The Micro-Engineering Board is very simple: it is almost nothing but through-connectors (plus an identifying I2C EEPROM for EOMA-68 compliance). The PCB layout has been completed (as of 2013jun05) and a first prototype will be assembled very shortly.

It is suitable as a test bench, as well as being suitable for experimental purposes as well as having the potential to turn an EOMA-68 CPU Card into a very simple Desktop PC. An Allwinner A10/A20 CPU Card in combination with this board would have SATA, Ethernet, USB Host, HDMI, SD/MMC, USB-OTG and take 5V power, as well as having internal access to 8 pins of GPIO and an I2C interface.

IMPORTANT MODIFICATIONS TO 1ST REVISION

  • remove R2 THIS IS REALLY IMPORTANT FOR THE NEWER EOMA68-A20 BOARDS
  • short out D1 and MAKE SURE YOU USE EXACTLY 5.0V power
  • put a wire between pin 1 and pin 11 on the underside of the PCB, on J4.

Features

  • Ethernet RJ45 connector with built-in transformer
  • SATA connector
  • 5V power connector (with capacitor and zener diode protection)
  • upright USB connector
  • 44-pin DIL header with remaining EOMA-68 pins (RGB/TTL, GPIO and I2C)

All parts are orderable from Digikey and are through-hole (pins) so can be hand-assembled. The gerber files can be made available if anyone wishes to print a PCB.

Pinouts

These are the pinouts for the 44-pin connector:

  • Pin 1 GND
  • Pin 2 LCD R0
  • Pin 3 LCD R1
  • Pin 4 LCD R2
  • Pin 5 LCD R3
  • Pin 6 LCD R4
  • Pin 7 LCD R5
  • Pin 8 LCD R6
  • Pin 9 LCD R7
  • Pin 10 LCD G0
  • Pin 11 LCD G1
  • Pin 12 LCD G2
  • Pin 13 LCD G3
  • Pin 14 LCD G4
  • Pin 15 LCD G5
  • Pin 16 LCD G6
  • Pin 17 LCD G7
  • Pin 18 LCD B0
  • Pin 19 LCD B1
  • Pin 20 LCD B2
  • Pin 21 LCD B3
  • Pin 22 LCD B4
  • Pin 23 LCD B5
  • Pin 24 LCD B6
  • Pin 25 LCD B7
  • Pin 26 LCD CLK
  • Pin 27 LCD VSYNC
  • Pin 28 LCD HSYNC
  • Pin 29 LCD EN
  • Pin 30 I2C-SCL
  • Pin 31 I2C-SDA
  • Pin 32 GPIO 0
  • Pin 33 GPIO 1
  • Pin 34 GPIO 2
  • Pin 35 GPIO 3
  • Pin 36 GPIO 4
  • Pin 37 GPIO 5
  • Pin 38 GPIO 6
  • Pin 39 GPIO 7
  • Pin 40 RES1
  • Pin 41 UART_TX
  • Pin 42 UART_RX
  • Pin 43 GND
  • Pin 44 +5V

Case available

A case is available for the MEB, pictures and example here: http://www.gplsquared.com/eoma_boot/eoma_boot.html

Pictures

These are very early 3D CAD/CAM prototypes, done prior to the PCB layout (which is now slightly different)

[[!img Error: Image::Magick is not installed]]

This image shows the early CAD/CAM of a Micro Engineering Board with an EOMA-68 CPU Card:

[[!img Error: Image::Magick is not installed]]

Here's the BOM on mouser.com:

[[!img Error: Image::Magick is not installed]]

Finished item! Many thanks to Firemoth Industries and to Leo for the work here. It's amazing to see this coming together.

[[!img Error: Image::Magick is not installed]]

Picture of a suitable MEB case, at gplsquared: