Inventortown shut down

I had to upgrade server, so I also removed the online compiler Inventortown. If someone have files there they want back, let me know. I have the old server.

I didn’t actually realize that many people used it, but some people have already requested files off it. The ‘servobot’ project, a very simple and cheap rover/bot that can be made for less than 10 USD-ish, is one project that has been quite popular.

I have therefore written some Energia code that should work ok for the same design. I haven’t actually tested it though, so if someone wants to test it and modify it if necessary, that’d be cool. The file is here.

Github support on inventortown

I’ve now added support for cloning a github project into your Inventortown project. Basically:

1. Create a new empty project on Inventortown.
2. Click the ‘git clone’ on the left
3. Enter the readonly address for the github project you want to clone. For example git://
4. If your project had multiple main-files, you have to delete the ones you don’t want (the example has several files with main in them).
5. If your project had a directory structure, you may have to change the relative include files. The above function copies ALL the .h and .c files into a single directory, so you have to change files because of this.
6. Click compile…

It’s a very untested function. Please report if it works or not for you, and give feedback to how you’d like the function improved.

Playing Super Mario Theme on MSP430

Adam at Inventortown came up with something quite cool. He copied Bob Somers’ code which can play music and compiled it using Inventortown’s online compiler.

UPDATE: I couldn’t get that project to compile properly after the compiler has been updated, as it was for the old MSPGCC.  Bob Somers has updated his code for the new compiler. So I got it from his Github again and made a new project which is here.

And a video of it playing. (After programming with the Inventortown uploader, you need to unplug the board and plug it in again for it to work).

3D printed simple biped with 4 servos

Here’s a simple biped I’ve printed using my Makerbot. It’s printed in clear PLA, which I think looks quite nice. The design is rather poor, but it walks ok. This one here runs with a standard radio control, but I’ve tried it with Arduino and Launchpad MSP430 also. Maybe I’ll fix it up to look a bit better.

It uses 4 cheap servos from Hobbyking, and a cheap remote from Hobbyking. You can easily build this robot with wooden sticks or similar, without a 3D printer. There are several examples on Youtube of this. This version is not as complex as my other biped, but this one is much simpler to build (and control). It uses a 2 cell LiPo battery and an ESC to convert down to 5V for the receiver and servos.

The 3D model is here:

Graphical development environment for MSP430?

I wonder if anyone would use a graphical development environment for the MSP430. That’s what inspired me to make the online editor (which is still standard C), thinking that maybe I should make something like’s interface, but for the MSP430.

I wonder what the best UI for something like this would be. I made a completely non-functional simple mockup of some drag-and-drop functions here, but I’m not sure what would be the best approach if I developed this for real… and of course, who would use it?

Simple MSP430 based servo robot

This is a very simple robot to make, with cheap components:

  • 1 x Launchpad MSP430: $4.30 (plus shipping)
  • 2 x cheap servos: $1.98 (plus shipping), easily modified for full rotation.
  • 2 x wheels. I 3D printed mine, but you can make these from many other things
  • 2 x light sensitive resistors (LDR).  < 1 USD each.
  • A battery pack with 3 rechargeable AA NiMH batteries, totalling 3.6 volts (Don’t use alkaline!)
The Energia-sourcecode is available here. I had to update this from C-code and the online IDE I had made (Inventortown). But since I took down Inventortown, I’ve made new code in Energia, but it’s untested. The pinout for example is definitely wrong, but hopefully it can be a basis for you to tweak.
Program the Launchpad, connect one servo to pin P1.0, one to P1.1. Connect the two resistors in series with VCC and GND in each and, and connect the middle point of them to P1.5. Then connect the power to the servos and to the VCC/GND of the Launchpad. Add a power switch for convenience. 3 x NiMH AA make 3.6 Volt which is fine for the Launchpad. If you use Alkaline batteries, the voltage may be too high, and Alkalines aren’t very good for robots anyway.
Servos have three connectors. The darkest on one side is ground and connects to ground (-) on the battery and ground on the launchpad. The middle is power and connects to the battery (+) and VCC on the launchpad. The third one (sometimes white or some other light colour) is the signal, connecting to P1.0 and P1.1 as mentioned above. You need to modify the servos for full rotation. This involves connecting it to a signal that centers it (90 degrees), opening it up, removing the gears, soldering the stick that goes into the potentiometer so that it won’t rotate any more, making the hole of the outer gear bigger, so it won’t stick to the pin but rotate freely, putting the gears back together. There are many videos on youtube for this, and it’s done in 5 minutes. It gives you a simple controllable gear motor at a low price.
This robot can be modified for example to a line (black tape) following robot, quite easily.
To assemble the robot, use for example double sided tape. Start with the battery holder on the bottom. Then tape the servos onto this. Then tape the Launchpad onto the servos. Done.
Here’s the video: