STEP 3 Assemble


Parts: I have decided to split this step into 3 parts, covering the main deliverables you need to create:
PART 1: ArduinoDUE board and Software;
PART 2: Shield board with components and boxing it together;
PART 3: Motor housing and pulleys.

PART 1: For me the easiest part is to load the software on the Arduino Due board. For this you need to download and install the IDE. Refer to the description from Step 2 – Software you need in order to complete this step. Most important part here is to install the load the sketch (rDUINO Scope program) on your Arduino Due board.

It is possible that you receive few Warnings during compilation, and this is due to a few transformation “StringToInt” I’ve done in an “old fashion” way, not supported by the current version of the IDE. Everything is OK until the compiler throw an Error and stop loading the sketch.

Now, take the TFT screen and attach it to the Arduino Due board as explained in the link here: http://www.elechouse.com/elechouse/index.php?main_page=product_info&products_id=2217

Once done, use an old SD card (I used one found in a box from about 10+ years. It is 128 MB) and copy the content of the “SD Card”. You can download the ZIP file from the rDUINO Scope website link: http://rduinoscope.co.nf/downloads.php Once you copy all the files on to the SD card, install the card in the SD card slot beneath the TFT screen.

At the end you should have Arduino Due board, along with the TFT Screen and SD card attached and the rDUINO Scope software running on it!

You should be now able to run the software and play around with it and it should look something like the image on the left. The first Part is completed!

NOTE: Please, note that the software might look to freeze from time to time when you play with it at this stage. This is because the motors and the other components are not connected, but the Arduino expects some input from them (e.g. as when the motors turn – Slew To).

PART 2: We got to the part of putting together all the components we have and wire them on a prototyping electronic board. At that point you need to decide how your rDUINO Scope will look like. For example:

Option 1
You can choose a 3 layer design as I did and have a smallest package possible (e.g. Arduino Due – level 1; Electronic board on top of Arduino as shield – layer 2; and finally the TFT on top of all – layer 3). Note that I had to replace original TFT shield with 40 pin. ribbon cable, which was a bit difficult but worth for me.
Option 2
You can choose a more spread way to put everything together as suggested by Elechouse.
Option 3
Another good approach is to have Arduino and the Shield with components in a separate box with passive cooling, and have a separate box, holding the TFT and buttons/switches.

NB!: You need to create a special cable in order to mount the TFT on the box cover. See HOW here!

Once you decide about your design, I suggest you to stack all elements roughly in the way they will be assembled and measure dimensions (width x height x length) in order to look for proper box on the market. It is important that you have your box with you during this assembly first to have a physical reference of what to expect and second to be able to quickly check if everything will fit in the box.

In the code I have defined Arduino pins to communicate with components and read/write data. You can revise them if you need to, but you need to make sure the wiring is done properly as the schemas below will refer to the original pin definition and wiring.

rDUINOScope wiring diagram
rDUINOScope wiring diagram

Now is the time to start soldering...
I've split the components in 2 parts: 1) Those resides on the shield on top of Arduino (RTC3231, BT HC-05, Piezo Speaker and DRV8825 drivers)... and 2) Those mounted to the box itself (GPS, DHT22, TFT Screen, All Switches and PS2 Joystick).
With this thinking I started to solder the Shield board as seen on the images below. I created wire connections from pin to pin and soldered all components to the board. Also the shield needs to have pins soldered that will slide into the ArduinoDUE slots exactly!

Once those were done, I connected the board and tested the shield! ... It wasn't working! :(
I checked the wiring and it turned out that I have created a bridge between 2 connections and I had to fix it. Please note that as of this moment I started to check every soldering with for issues as I really got lucky to not burn my Arduino or anything else with the wrong wiring.

NB! - Make sure you check all connections!

Now as all components are soldered in place, I suggest you to also connect the motor drives and test the entire setup. It should work without glitches at this point.
Make sure you use suitable power adapter (12V, 1.6A) and connect the motor drives before the power is ON! NB!: Never connect motor drives when DRV8825 is under load as it might burn the drivers!

Once the shield is ready, take the box and started to laid out all components and plan where you need to drill holes and their sizes.
The best way to cut holes is with a small pocket knife (at least for me). It really doesn't matter if it is a round hole or a square one. You can easily carve it with a sharp small knife.
The only exception is for the screen, where you really need long even and square hole. I asked for a favour and my father did it on his cutting machines.

GPS Module HotGlued on the top side of the box ON/OFF Switches on the top side Box is drilled so that DHT22 sensor can stick outside USB Cable connected to the Native USB of the Arduino Fan for cooling Connectors for Motors and 12V Power Supply RA Motor driver DRV8825 and Cables DEC Motor driver DRV8825 and Cables BlueTooth module HC-05 soldered on the board RTC3231 Clock soldered on the board TFT Screen Ribbon - this is the Elechouse slot Power Supply goes to the DRV8825 drivers with added capacitor Piezo Speaker soldered to the board Resistors for Day/Night Mode. The switch is mounted on the front panel next to the screen and PS2 joystick MY SETUP:
(Explore the image on the left with your mouse. Explanations will PopUp!)

  • First I drilled all the holes for switches, jacks and cooling. You can see on the picture that I've decided to HotGlue the GPS sensor to the top of the box, so that the antenna always face the sky, secondly I have drilled 2 holes for the On/Off switches on the top too. I use 2 switches because this way I can feed separately the Arduino and the Motors.

  • HotGlued all the parts like: DHT sensor on the right hand side of the box and switches.

  • I glued the Arduino DUE board to the bottom of the box and connected the extension shield on top (as seen on the picture)

  • I even put a small fan on the left hand side of the box to cool down the DRV8825. It turned out that this is not needed as they stay pretty cool at about 40°C

  • I have drilled the box on the bottom left side and have connected a USB cable to the Arduino native USB. This way I was able to load newest versions of the software and make small changes without opening the box.

  • On the front face of the box I drilled a hole for the screen, the PS2 Joystick and Day/Night mode switch. You need to use connectors for these parts in order to ensure that the top cover can be opened for servicing. Not visible on this image.

  • On the bottom side I drilled holes and put connectors for the RA and DEC motor drives and 12V power supply.

  • All wire connections, which are not part of the Shield Board, have to be laid out around the boards

  • (Explore the image on the left with your mouse. Explanations will PopUp!)