Danguinololu

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Danguinololu

Release status: Working

Danguinololu v2 - Assembled PCB (top).jpg
Description Danguinololu v2.0
License GPL 2.0
Author neuronix
Contributors
Based-on Sanguinololu
Categories Electronics, Development, Mendel Development
CAD Models
External Link


This design is fully tested and has been used to successfully control a Prusa Mendel. Based on generated interest, we are considering providing the Danguinololu as a kit, either as a fully-assembled working PCB (including pre-loaded microchip), or as a PCB plus individual components for anyone who wants to have a go at hand-soldering the board. Please contact us here to let us know what you think of the board and/or whether you would be interested in purchasing a Danguinololu!


Contents

Overview

The Danguinololu v2 is a brand new take on the popular Sanguinololu RepRap controller. It is a fully-integrated solution with a completely redesigned layout that used parts based on an availability/functionality/cost trade-off.

The stepper motor drivers are integrated into the board, reducing its overall size and removing the need to purchase the additional four Pololu A4988/A4983 drivers and hence reducing overall cost. Although the modular feature is lost, burnt out or damaged motor drivers are a rare occurrence in this controller, especially since the use of a large (85 mm length) fan has been implemented in the PCB design and provides more than enough cooling for the motor drivers and FTDI chip.

The Danguinololu v2 powered on.
A close-up of the diagnostic LEDs in operation.

Also, status indicator LEDs are a prevalent feature of the new board for all motor drivers, extruder, and temperature sensors (in addition to power and FTDI comms), which prove extremely useful when troubleshooting. Plus you get the added cool effect of a dozen flashing LEDs!

The redesigned controller is based on the Sanguinololu v1.3a schematic, hence all firmware that works on the latter will also work on the Danguinololu.


The circuit board v2

The second version sports several improvements such as improved power management, better airflow to components, diagnostic LEDs, more efficient parts layout and quick-release connectors.

Completed PCB (top view), with upgraded layout and new motor drivers.
Completed PCB (bottom view). New motor driver footprints and area covered by an 85 mm add-on fan can be seen.

The main change from v1 however is the replacement of the quad-flat no-leads (QFN) packaged chips by Texas Instrument's DRV8811 driver chips. Their 28-pin heatsink thin shrink small outline package (HTSSOP) packaging is similar to the FTDI chip’s surface-mount design, making them much easier to handle and solder. Hence, assuming you have the skills and steady hand to solder an FTDI chip by hand, you can also solder this entire board by hand!

2nd version PCB with TI DRV8811 driver chips. Their footprint is very similar to that of the FTDI chip (far right), making it possible for the whole board to be soldered by a steady hand.
1st version PCB with small A4983 driver chips. Soldering required use of a stencil, oven and corrective soldering by hand.

The board includes mounting holes for an 85 mm PC fan, which takes care of cooling all the heat-prone chips.

The screw-in connectors in the first design were replaced with more ergonomic push-down connectors. They are much more easy to use, do a great job of holding wires securely and are stiff enough that wires will virtually never get accidentally pulled out.

Schematics.
Schematics focusing on AVR and FTDI chips.
Schematics focusing on 2 of the 4 drivers.
PCB entire layout.
PCB 3D top view from DesignSpark PCB.
PCB 3D bottom view from DesignSpark PCB.
Assembled PCB top.
Assembled PCB bottom.


The circuit board v1

The Danguinololu was started as an attempt to create an easy-to-assemble, all-in-one board with a professional design, while simultaneously learning more about the functionality of the Sanguinololu schematic. This eventually learnt to a variety of improvements which eventually made the Danguinololu easy to wire up and troubleshoot.

Completed PCB (top view), with original A4983 driver chips.
PCB layout (bottom view). The particularly small A4983 driver chips which caused soldering issues can be seen (square footprints with multiple input pins).

The Allegro A4893 chip used in Pololu’s stepper motor drivers comes in a square-shaped QFN-package. Apart from their footprint being extremely small for such an IC, the 28 pins are very hard to access from the sides of the chip. Since a reflow oven is not a standard piece of equipment in most people’s toolbox, hand-soldering this board is no easy challenge. This is one of the major issues we addressed in v2.

The green wire connectors have flat-head screws for inserting wires. They do a good job of holding the wires securely, but proved to be very time-consuming when wires need to be changed around often.

Schematics.
PCB layout.
PCB 3D top view from DesignSpark PCB.
PCB 3D bottom view from DesignSpark PCB.
Assembled PCB top.
Assembled PCB bottom.


Design

All design info here is for version 2. You can download the required files by clicking on the links below. The schematics and PCB layout were created using DesignSpark PCB, a free electronic design package by RS Electronics.


Schematic and board layout

Danguinololu schematic (.sch format): Media: Danguinololu.sch

Danguinololu board layout (.pcb format): Media: Danguinololu.pcb


Bil-of-materials and Gerbers files

Danguinololu BOM (.xls format): Media: Danguinololu BOM.xls

Danguinololu Gerbers (zipped .rar): Media: Danguinololu_Gerbers.rar