Posts tagged ‘Dwengo’

Using MPLAB.X on Ubuntu 11.04 64bit with Dwengo board

I have been using Pinguino for quite some time to program my Dwengo board from within Linux, but as the source code grows larger, the Pinguino “sketches” aren’t always the most convenient code structure. In addition, and more important, I notices some weird unstable behavior where initializing a string variable with string A worked fine but initializing it with another string resulted in the code not being able to compile. As Microchip has released a cross-platform IDE called MPLAB X, I tried setting it up on my 64bit Ubuntu (v11.04 aka the Natty Narwhal) today. This article is a step-by-step tutorial on how to compile your code with MPLABX, load it on the Dwengo board and run or debug it using the Dwengo programmer.

  1. Go to the MPLABX download page, select “Linux x86 (32 bit)” as the platform (there is no 64 bit version) and check the boxes “MPLAB IDE X” and “MPLAB C18 Lite Compiler for PIC18 MCUs”. Then hit “Download now”. Do it fast, because a reeeeally annoying video (which you can’t stop) automatically starts playing upon loading the page!
  2. Two installer files will start downloading, make them executable:
    chmod +x ./
    chmod +x ./mplabx-ide-beta7.02-linux-32-bit-installer.bin
  3. You can try to run the graphical installers (just double-click the files), but on my 64bits Ubuntu this gave the elaborate “Segmentation fault” error message. The problem is documented here, and solved by running the installers in text mode. So first install the C18 compiler:sudo ./mplabx-ide-beta7.02-linux-32-bit-installer.bin --mode text

    and then install the IDE

    sudo ./

    edit: @markgross got the graphical installer working, as explained here

  4. Just one more hurdle to go! As the MPLABX is a 32bits version and uses Java, it expects to run on a 32 bit java virtual machine. However, the default Java you’ll install on Ubuntu via the package manager is a 64bits version. Follow the instructions on this site to run the IDE using a 32 bits Java version. Basically you install a 32 bits Java in some folder and create a shell script which points the JAVA_HOME and PATH environment variables to this Java.
At this point, you installed the environment succesfully and you should be able to start it without getting any errors. I start the script created in step 4 with sudo, because otherwise I do get some errors (and I’m not that into sorting out all kinds of file permissions) of files being read-only.

Now we will install the Dwengo library. Download it as a zip file from here, and extract it. You’ll get two folders, one with a .lib file in it and another one with the header files (.h extension). In a terminal, cd to the extracted folder and copy the .lib file to the lib folder of mplabc18 and the .h files to the /h/ folder (the exact destination folder can differ on your system depending on where you installed C18):
sudo cp ./lib/dwengo.lib /opt/microchip/mplabc18/v3.36/lib
sudo cp ./h/*.h /opt/microchip/mplabc18/v3.36/h/

Ok, we are set to go! Fire up the MPLABX IDE and let’s create a project… In the file menu, click “new project”. A dialog pops up. Select “Standalone Project” and click “Next”.

The Dwengo board ships with a PIC18F4550, so select this as the device:

The Dwengo programmer is compatible with PICkit2, a MicroChip programmer/debugger device. So select this as the tool and click next. The nice thing about using this device with the MPLAB software is that we will be able to actually debug our code! That is breakpoints, step-by-step and other goodness instead of tediously writing variables to the LCD.

Select C18 as the compiler toolchain:

Finally, name your project:

A project structure is created, shown on the left. We will start out by adding the Dwengo library by right clicking “Library Files” and selecting “Add existing file”. Select the .lib file we downloaded earlier.

Next we add the linker file, needed for successfully compiling your code. Right click on “Linker files” and select the file 18f4550_g.lkr which you’ll find in the folder /opt/microchip/mplabc18/v3.36/bin/LKR (or something similar, depending on where you installed C18).

And now, finally, we can add some actual code 🙂

I used the Dwengo “blinking Leds” example, which you can find here. Once the code is added, right click your project and click “clean”. This will remove any previously compiled code and asserts that you are not working with any old version of your code.

Now right click your project and click “build”. I got a lot of errors on the console window, but clicking “build” once more successfully compiles and links all code. Perhaps this is some error with the IDE (remember this is still a beta), so remember to hit “build” twice every time… You should get output similar to this if the building succeeds:

make -f nbproject/ SUBPROJECTS= .build-conf
make[1]: Entering directory `/root/MPLABXProjects/the_stalker.X'
make  -f nbproject/ dist/default/production/the_stalker.X.production.cof
make[2]: Entering directory `/root/MPLABXProjects/the_stalker.X'
make[2]: `dist/default/production/the_stalker.X.production.cof' is up to date.
make[2]: Leaving directory `/root/MPLABXProjects/the_stalker.X'
make[1]: Leaving directory `/root/MPLABXProjects/the_stalker.X'

BUILD SUCCESSFUL (total time: 162ms)
Loading /root/MPLABXProjects/the_stalker.X/dist/default/production/the_stalker.X.production.cof...
Loading completed

And now the moment you have all been waiting for... Make sure you connected the programmer with USB to your computer and that the programmer is plugged into the Dwengo board. Hit "Run project" in the "run" menu. You should get the output

Connecting to programmer...
Programming target...
Programming completed
Running target...

You can also double click a line in the code and run “Debug project” from the debug menu. Now you can step through the code to inspect variables and check the flow of your code.. nice!

I hope this guide helps anyone also trying out the new MPLAB X beta on Ubuntu. The installation is a bit difficult, but it looks like a really cool product. Especially the debugging is something that will save me countless frustrating hours 🙂

August 28, 2011 at 8:44 pm 4 comments

Introducing the_stalker: controlling a camera using Dwengo

I finally found time to play with some electronics again this weekend, so I decided to dismantle my old camera and try to control it from my Dwengo board. A simple plan, so let’s go ahead! The camera is a cheap Aiptek DV3300 camera / camcorder which was my trusted companion for many years and with which some of Overimpe’s best underground heist, crime and weird psychedelic space-time-travelling movies were shot.

First I had to disassemble the camera, which went fairly easy (some screws and some careful pulling here and there). Once inside the camera, I saw that the plastic buttons on the outside just pushed some standard pushbuttons on the inside. After measuring the voltages when pressed / released, the various buttons seem to just pull a line to ground upon being pushed.

Because the buttons are placed fairly close to each other, and my soldering skills are a bit rusty, I decided to start with just controlling two buttons: the power switch and the shutter button. This would allow the microcontroller to start the camera, take a picture (or record a video), and power off the camera. So I soldered two wires to the buttons, put a big blob of hot glue on it (see picture below) and guided the wires to the bottom of the camera, where I could make them come out of the camera through the removed screw of the tripod.

Below you see the re-assembled camera, with some wires coming out of it at the bottom.

And below is the entire test setup. The Dwengo microcontroller board on the right listens on a serial interface (connected to a laptop) for commands telling it to power on the camera and to start recording. Once these commands are received, a pin on the PIC microcontroller is pulled HIGH. This pin will make a transistor go into saturation and connect the camera line (power or record) to ground for a few seconds. This simulates a button on the camera being pushed.

For those interested, the breadboard layout is shown below (click on it to open a larger version). I only included one line in the schema, because the second line is basically the same circuit duplicated. More information about how the circuit works can be found on this excellent site.

And a video as final proof that it works 🙂

The code can be found on github. It is really, really ugly code though, because I had a LOT of problems getting it to run ok (I think something is wrong with my Pinguino bootloader). The code will be cleaned up in future commits though.

The next steps for this project will be to move from a breadboard to a soldered circuit and maybe use Bluetooth instead of a serial cable. I think in the end I will try to embed the circuit in a bird-house in my garden to spy on those shady birds, and trigger the video recording with a motion detector (when a bird enters the house). I’m not sure about that yet though, any ideas are welcome 🙂

PS: Thanks to the Dwengo people who gave me a free Dwengo starterkit plus as a gift in appreciation of my blog! So if you do a cool project with the Dwengo board, be sure to write about it 😉

July 11, 2011 at 10:16 pm 1 comment

Creating a custom Fritzing part for the Dwengo board

A problem I always have with my robots is they end up as a messy spaghetti monster with lots of wires leading to hidden places on the robot. When (purely hypothetically) the robot bumps into a wall some wires get loose and I have to figure out what was connected to what again.

I should keep some documentation on my robot. I wanted to do this with Fritzing, a cool open-source program for drawing breadboard-prototypes and more. Lots of parts are already available in Fritzing, like an Arduino, a servo, chips, and so on. As the Dwengo board was not yet available as a Fritzing part, I created it myself.

A Fritzing part is composed of SVG vector graphics: one for the breadboard layout, one for the schematic layout, one for the PCB layout, and one for the icon. These graphics can be created in InkScape. I never worked with InkScape before, so I had a hard time drawing the breadboard layout. The easiest way to create the layout was to take a photograph of the board, then import that in Inkscape, and draw over it. I reused the svg images from the existing Fritzing core parts to create the final layout.

Because Fritzing has to know which part of the image is a connector where wires can start and end, one has to create connectors. This is done by creating rectangles with the names connectorXterminal and connectorXpin (where X is the connector number). In the schematic and PCB layout, the same connector have to exist with the same name. This way, Fritzing can keep the three layouts in sync, so if you create a prototype in the breadboard view, you immediately get a schematic view and a PCB view.

For the SVG files of the schematic view and the PCB view, I started from a header row (for the schematic view) and from a regular chip (for the PCB). Once these were done, I created the part in Fritzing:

In the parts editor, you can label all the connector pins and give them a description. You can also add and remove connectors if necessary. As you can see from the image, I created connector pins for the Dwengo connector on the left, and for the driver chip output on the right. The pin labels mention the PIC pin number and the corresponding Pinguino pin number (see

Download the Fritzing part.

Now that the part is created, the fun can start :-). It only takes about 5 minutes to redraw my robot schematic in Fritzing. One problem I had was that the Bluesmirf component doesn’t exist in Fritzing, but I used a “mystery component” with 5 pins instead. The resulting prototype is shown below:

As you can see, this is a nice and  easy way of creating a breadboard prototype of your project. You can download this diagram from its Fritzing projects page. Fritzing features a lot more cool features, like automatically create a parts list, create an etchable PCB layout or Gerber files as a Pdf, …, which help you in sharing your project with others and in going from a prototype on a breadboard to a real product on a PCB!

January 8, 2011 at 10:10 pm 4 comments

Bluetooth communication between BlueSMIRF and Ubuntu

A quick post on how to set up the Bluetooth communication between Ubuntu and a BlueSMIRF Modem.

My laptop was broken recently, and after getting a free new motherboard from the kind Sony people I reinstalled Ubuntu and tried to get all my software running again. Today I tried setting up the Bluetooth communication with my toy car’s BlueSMIRF (see previous posts) and  my laptop, and decided on documenting it. So here’s how to do it:

  1. (optional) It’s easiest if you can see what is happening on the BlueSMIRF side. Therefore, you’ll need a serial (TTL) to USB convertor like this one. Alternatively, if you have a Dwengo board (or similar), you can use that one by simly removing the PIC18F chip for a while:

    Now you can monitor the commands and data passing through the BlueSMIRF by opening “serial port terminal” (install it through the Ubuntu Software Center) on /dev/usbtty0 at the speed of your BlueSmirf (default 115200 baud)

    Details on the commands available are available in the Roving Networks Command datasheet.

  2. I didn’t get the default Ubuntu Bluetooth tool (the B in the taskbar) to play nice with the BlueSMIRF, so I installed “Bluetooth Manager” (BlueMan) through the Software Center.
  3. Power the BlueSMIRF, it should start blinking rapidly for about a minute. This means it is waiting for a connection. Once the rapid blinking stops, you can’t connect anymore!
  4. Click on the B in your taskbar of BlueMan, a window should open showing the Bluetooth devices in your environment. One of them should be FireFly (the BlueSMIRF). Right click on it an select “connect to SPP”:

    (the name in the screenshot is robot-719A instead of Firefly because I changed it earlier)
  5. Because this is the first time you connect to the BlueSMIRF, it needs to be paired. Therefore, Blueman will ask you the pass phrase. Enter “1234” (without quotes), this is the default passphrase of the BlueSMIRF.
  6. The bottom of the Blueman screen should now say “Serial port connected to /dev/rfcomm0”. Now you can open a serial connection to /dev/rfcomm0 using serial port manager (or from within a script) and start communicating 🙂
    The LED on the BlueSMIRF should turn green.

That’s it! Now the pairing is done, and you won’t need to enter the passphrase the next time you connect to the BlueSMIRF.

    December 19, 2010 at 11:15 am Leave a comment

    Using Dwengo board as a Pinguino

    The Pinguino project is a relatively new project that tries to build an Arduino-like project with a PIC processor. The project comes with a nice and simple IDE and a bootloader so programs can be placed on the PIC very easy.  I found the Dwengo board I own is compatible with the Tiny-4550 Pinguino board, so it is possible to use the Pinguino IDE and bootloader with the Dwengo board. 

    Here are the steps I followed on my Ubuntu (Karmic) machine to get things fired up:

    • Install wxPython as explained here
    • Download the latest Pinguino IDE from the hackinglab dowload index. Extract the archive. Run the IDE by running the Python script from the terminal. Put sudo before it to run it with administrator rights, because otherwise you’ll get a ”Could not change device” error! The IDE looks like this:

    • With the PIC18F4550 we need the second version of the bootloader (see Pinguino tutorial site). It can be dowloaded here. To put the bootloader on your PIC, I used xwisp, which is a Windows program (I ran it in a Virtualbox virtual machine).
    • Once the bootloader is on your PIC, connect your board via a USB cable to your PC. Hold the reset button and the “up” button on your board, then release the reset button. The bootloader program knows you want to place a program on it now.
    • Open up the Pinguino IDE and type e.g. this program in it:
    // Testing input with Pinguino
    // jean-pierre MANDON 2008
    // modified kr3l for DWENGO
    #define PIC18F4550
    void setup() 
    pinMode(0,INPUT);         //button
    pinMode(21,OUTPUT);    //led
    void loop() 
    if (digitalread(0)) digitalWrite(21,HIGH);
    else digitalWrite(21,LOW);
    The pin numbers used here are as in the Tiny-4550 schematic:
    so pin 21 as used in the program is actually pin 19 of the PIC processor.
    • press the compile button, then the “put program on pinguino” button. The program starts running after a few seconds. If you press the center button one of the leds will go off.

    I think the Pinguino project is a really cool initiative and I hope they keep working on it. More experiments will be conducted soon!

    December 31, 2009 at 3:35 pm 1 comment


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