So, the controllers all connected up. Even got the Meanwell PSU to fit in there, it’s a tight squeeze and there’s a little bit or wireharness to ziptie up to make it all look neat once it’s working 100%.

The I2C pinout of the RAMBO and RAMPS are the same (link) so I can plug the LED controller for the LDP8806 Strips in, it’s a Arduino Pro Micro using a Mega32U4 processor.

I2C Pinout for reference is
Pin – Func – wire
1 – VCC – BLK
2 – GND – Green
3 – SDA-20 – Red
4 – SCK-21 – Blue

Looks like I may not use the LED controller for powering the Arduino, many warnings on externally driving +5V, I’d have to opne up the USB +5V and then direct drive that net with the LED switcher, with some sort of filtering.

We’ll save that for later, for now , powering with the USB seems to work Fine.

What’s not working is the stepper controllers, they only turn in one direction, that seems to be common to all 4 motors, the 0.9 have plenty of holding torque once I turned up the current a little bit.

The Hot ends heat up, but I think the thermistor needs calibration as does the bed, what I do see is bad behavior on the bed driver, like it’s not getting a solid off signal or it’s driving PWM so fast the FET is in it’s transition region, which is high rDS, so it’s gets hot. The initial power up smoked a cheap inline fuse, fortunately I picked up an ATM type fuseholder at Breed & Co and replaced it.

Time to put a scope on the motor drivers and the bed FET Gate pin.

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  • brogue