RepRap 1.2 M-Board C1 & C2

Hi all,

I'm building my first RepRap and putting together the ver. 1.2 Mother Board.

I've noticed that in the BOM and the assembly instructions that C1 and C2 are 15pf.

Yet in the schematic and on the board's silkscreen it says 22pf.

Which is correct? - Or does it make any difference.

Since I ordered my parts per the BOM, I'm using the 15pf flavor.

Am I screwing things up from the start?

Thanks in advance.

Eddie G.

I don't recommend Gen 3 motherboard. The RS485 communication between the motherboard and extruder controller is problematic not to mention that it wasn't designed for stepper motor on the extruder. There are also more chances of wiring mistakes and problems. Build RAMPS or Sanguinololu instead.

I don't have the Gen3 schmatics handy right now, but I think you're talking about the two caps connected to the clock crystal.

As you have the 15 pF ones already, use them. The worst thing to happen is the clock crystal not oscillating reliable. You'd end up with an unresponsive ATmega as soon as you burn the fuses to use that external crystal. In that case, replace them with the 22 pF ones.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY