Cube3 teardown - Electronics

Here are some pics of the LCD and controller boards in the Cube3 during my initial teardown. (I found it strange that I couldn't find any detail of what the MCU and motor drivers were for this guy while I was researching it online.)

To get to the controller board and LCD, you must remove the outer shell of the printer. I simply followed the teardown steps from the OpenBuilds forum thread.

Cube3 with outer plastic shell removed.

To get the front shell off, you have to disconnect the cable to the LCD first.

The LCD and button board are attached to the front plastic shell. To remove the board, unscrew the 4 small Phillips-heads (and don't lose the button, it's not connected to anything!)

It looks like a 3" LCD from a cell phone, with a 4-wire resistive touch screen. A company called "Lincoln Technology Solutions" made the module.  

There's a 16-pin QFN part on the module that is probably the controller for the backlight. I assume the interface to the LCD itself is SPI, considering the small number of wires. 

The main controller board has 5 motor controller chips on it. One for each axis and extruder. 

The motor controllers are TI's DRV8811. The 8811 seems to be the little brother of the much more common DRV8825. It supports a peak current of 1.9A and 1/8th microstepping, compared to the DRV8825's 2.5A peak current, 1/32nd microstepping. (I've read that the DRV8825 really shines at 24V, which would explain why this system runs at that voltage instead of the more standard 12V.)

The biggest surprise of this teardown was the make/model of the controller micro. Instead of running on the prolific AVR architecture, which powers almost all hobbyist 3D printers at this point, or an ARM Cortex M3 or M4, which are the up-and-coming contenders, the Cube3 is powered by a Microchip PIC32! That's definitely a shock. The PIC32MX695F512L is an 80MHz MIPS M4K micro with 512K of flash and 128K of SRAM. The peripheral set, other than USB host, is about equivalent to an AVR/ low-end ARM: 16-channel 1 MS/s 10-bit ADC, 5x 16-bit timers/PWM, 8-channel DMA, 2x comparators. The kicker is it's priced around $10/each (in single quantities)... which is what an AVR MEGA2560 costs, and is probably double that of an ARM. (The M3 in the Monoprice Mini is less than $1 per.)

The wifi module is also made by Microchip. (I didn't look this one up because it's not exciting.)

There's also a Bluetooth Low-Energy module on the controller board. I haven't used the mobile phone app for the Cube3, but that's probably what this is for.