Bluetooth version

Stackduino-G2 board controller Bluetooth version

JANUARY 2018 NEWS:

a simplified version of this PCB board is available here: BT-boxed

I built a Stackduino-G2 controller board with Bluetooth support, via HC-06 module so I took this opportunity to improve my documentation and write a simple guide on how to build my board. Let’s start with the partlist.

• Single side or double side prototype board
• Arduino Nano ATMega328, original or ebay clone (for chinese clone using CH340 chip you’ll need a windows driver like this one)
• Stepper motor driver module (Allegro’s A4988 or DRV8825 drivers)
• Power jack
• RJ11 6P6C right angle socket
• 3.5mm stereo socket
• 4N35 optocoupler (2)
• Angled slide switch
• 3mm LEDs with resistors (optional)
• 330Ω resistor (2) for optocouplers
• female and male pin strips (see below for some dedicate mods and links)
• HC-06 Bluetooth module

The final assembled board should look like the image on the right.

I’ve drawn a layout with traces and components using the free drawing program Inkscape to make it easier the step-by-step building of the controller board. Drop me an email if you want my Inkscape file for convenience, or download the PDF version of this guide at the bottom of the page.

First of all, we will mount and solder the bigger components like RJ socket, power jack, stereo socket togheter with strip pins. The remainder of the components will be mounted with respect to these parts’s pins.

Let's start with:

Pin strips and main jacks and socket

The pin strips for the Arduino and Motor’s driver boards are simple and easyto find typical Arduino’s pin strips, while the strip pin that will be used for the HC-06 BT module requires a simple modification, shown in the following images.

The HC-06 module requires a pin strip like the one typically used for stackable Arduino boards. They are of type ‘stackable long legs female header (available here).

The four long legs shall be bent at 90-degree angle so the HC-06 module can be mounted parallel and lying down on the board to save space vertically. To do this insert the strip in the HC-06 pins and bend the strip’s pins at 90-degree from their base (see picture below). Mount this assembly on the prototype board and check for the right positioning, then solder the four strip pins and extract the HC-06 module.

The second four legged pins strip, the male’s one, is sligtly modified as well. The principle is the same, the pin strip has to be of long header type in order to allow bending of its legs. In this case of about 45-degree. This strip will be used for stepper’s driver motor’s phases connection.

Regarding the 4N35 optocouplers, we need Round pin female sockets type (image at right), like this one.

The sockets listed above in the partlist needs some additional mounting holes to be drilled on the prototype board. The power socket’s footprint is compliant with the 2.54mm standard pitch and it needs sligtly bigger hole only (2.5mm for the blue circles and 3mm diameters for the brown circles in the image below).

Here at right a drawing of the first layout of wiring bridges to place on the bottom of the board. I used short branch lines of rigid copper wire but of course is up to you to choose better alternatives. Many connections can be realized on the bottom side of the board. Pay great attention to potential short-circuit that may occur due to wires and soldering points close proximity. In figure 6 a first set of bridges are shown and are related to the components just mounted in. For long wires like the longer red one in the figure it is adviced to place additional soldering points to fix the wire to the board surface more firmly. Refer to the photo of my board below.For convenience, here is a picture of the board shown from the bottom side, as we see it during work.

My prototype board is labeled exactly as you can see in the picture but your can differ, so pay attention to the board’s hole numbering layout.

Other components and second set of bottom bridges

Now is time to mount and solder the remaining components.

Then adds some bridges between LEDs and their resistors (or use their own legs) and connect the leads of the 100uF capacitor to the driver’s mounting strip pins.