Custom board for G-Rex G101

[Matty Zee]

Has anyone built a custom board to suit the G-Rex G101? I have purchased a '101 board with the Rabbit module in the hope of using it with Mach3.

I originally thought it was going to be a simple case of providing some screw terminals for the signals i need access to, provide a 5VDC and 12VDC to a couple of pins and be able to drive some LED (incoporated in a custom display). But i'm thinking it may be more complex than i thought.

Firstly, what pins do i need to provide power to the G101? The manual lists about 22 pins as +5VDC but i'm not sure which are supposed to be the supply and which are just distributing the 5VDC for convenience.

Also, is the '101 loaded with exactly the same components? can i use the circuitry shown on the G100I_O.pdf to add some LEDs to the general purpose inputs or do i need to remove the 1.5k pullup on the 101 and add the 'LED and resistor combo' as the pullup on my board?

I have similar questions regarding the step/dir outputs...

Thanks for anyhelp anyone can give.

[ger21]

It would probably be a lot easier to send it back to Gecko and have them turn it into a G100.

[Matty Zee]

I'm not afraid of the challenge, just wanted to see if anyone else out there has done it.
Without details of the '101, i'm not sure if i need to supply +5VDC to all the pins labelled +5VDC (assumes they aren't internally connected) or if a particulare pin is designed to be the supply (and the power is distributed within the 101 board).

[Matty Zee]

Header CN5 is labelled as miscellaneous and is described as providing (amoing other things) "Power supply ground and 5VDC". So i assume i provide 5V/GND to pins 9 & 10 respectively. I gather the 5V on the CN3/CN4 are distributed for convenience when interfacing to other circuitry.
But i'm still a bit stumped where the 12VDC supply is needed...

[ger21]

Found this in the manual.

Fig. 4 General Purpose Outputs: The G101 uses ULN2003A output drivers for the General Purpose Outputs. The outputs are rated at 100 mA maximum current and at a voltage of +5V to +24V. The external +5V to +24V power supply connects to any of the CN1 connector pins marked ‘5 to 24 VDC’. The ULN2003A drivers have integral collector to power supply ‘catch’ diodes, so inductive loads can be driven directly.

[Matty Zee]

Thanks Gerry. Was just reading that exact part. The G100/G101 differences says a 5VDC and 12VDC supplies are required so that threw me a bit looking for a +12 rail. But it seems it can be a anywhere from 5-24VDC.
Thanks again...

[Matty Zee]

So what about the LED indicators... any ideas?
1. Do i need to have an extra buffer IC on my interface board to drive the circuit shown in G100I_O.pdf or
2. Do i need to remove the 1.5k pullup on the G101 and have a LED and limiting resistor on my board to pull the line up or
3. something else?