Nicola's Awesome Projects

Ardubee schematics

2009-03-31T12:31:00.002+02:00

Here's a first attempt at drawing the schematics for my Ardubee board. I'm very new to kicad so maybe it contains errors of all kind..

Ardubee, or an xbee-arduino board

2009-03-30T10:57:00.003+02:00

So, i'm working with my robot and i have a problem: the board is deep inside the case, and i have to unscrew it to open and connect the usb cable.
I have an XBee board already inside, so i could use this tutorial to wirelessly program it.
Since this looks like a recurring problem, and since i have many project in mind that use Xbee, i tought: why not having a board with an XBee and an ATMega together? No adapters, no usb, no costly FTDI chips. Sounds cool, uh?

So i went on and installed Eagle to design the board, got scared, disinstalled Eagle and installed Kicad. Much easier. I searched around for the ATMega168 and XBee kicad components, that i found here and there, and started designing the board.

The idea is to have a 3.3V level for the whole board, just to avoid level shifting hassle and such.

The board should be quite easy to make. Stay tuned for some pictures :)

Many steps forward for the robot controller

2009-03-11T14:02:00.002+01:00

Hello! So flu cought me and i'm home from work until friday, basically having 4 whole days to work on my projects.. isn't it great ? it would be even greater if i hadn't to fill thousands of handcarechiefs with what came out of my nose. But enought with my body fluids! I'm writing to show you the progress with the controller. I have completed the circuit board, making a "naked arduino" with an xbee adapter. This took about one whole day. I also made great progress with the container and the structure, and man, that was some real pain. All have to be planned and tightly placed in order for everything to fit correctly inside the box.

Anyway, i reached a good point. Now i only have the two joystick and two leds (that will be used as output devices), in future i'll place some buttons and such.

So, i tested the board by connecting the two leds to the two potentiometer of the right joystick, and magically it all worked at first try! I planned the board with great care :)

So, before i'll post some pictures, here's the video!

The Phase Two has begun

2009-03-09T14:39:00.001+01:00

Finally, i got it! :)

I hate when this happens

2009-03-03T11:44:00.003+01:00

You purchase an item, and as soon as you start working on something to mount it and get crazy, they start selling a breakout board.

This is exacly what happened with the thumb joysticks!

Now, keep on with the way i'm mounting it, or purchase a couple of this and wait months to arrive ?

Problem solving on the Killer

2009-02-28T22:21:00.002+01:00

So i worked very little lately, since my brother started playing Starcraft again and he made me wish to play it again too :) So i wasted many evening on that instead that on robots. Man, that game still rocks after more than ten years!

Anyway, i had an issue with the Killer.. Basically, after a minute or so of operating, the arduino board freezed and the robot became unresponsitive.

After some heavy debuggin, i didn't found anything. I've noticed that using standard Arduino Serial library instead of AFSoftwareSerial that i was using, it works. I used that to communicate with the XBee module. So it must be something with AFSoftwareSerial, that btw, if you don't know, is a library for serial communication in software made by LadyAda. The serial connection is heavily sinchronized, so making it in software is an hard job. Maybe something in my setup messes with it, and so it hangs. Switching to the standard Serial, which works in hardware, fixed the problem.

The only problem is that the primary serial port is also used to download programs into the arduino, so i'll probably have to disconnect the xbee every time.. Well, whatever :)

Universal Remote Controller

2009-02-19T13:47:00.004+01:00

So, to control my killer robot, i obviously need some kind of controller. Don't you expect me to go around killing peoples while carrying my laptop and using the arrow keys ? :)
Just joking.. my robot won't kill anyone. (Not enought firepower) :)

Anyway, i decided to make a small, hand held, xbee base, arduino powered controller, since it will not be tied in any particular way with the killer robot, it will be avaiable for future robots too, hence the "Universal" in the name.
Initially i considered adapting an existing Playstation controller, but then i realized it doesn't have very much space, and the appearence of these lovely thumb joystick on sparkfun definitely made me decide to roll my own controller. It will look much cooler, btw.

So, here's some of the planned hardware:

Part list:

2x Thumb Joystick
1x Potentiometer (with knob)
2x Microswitch (as momentary buttons)
Various leds (as feedback)
Arduino circuitry (see below)
maybe a dip switch (for extra controls)
maybe a buzzer (for feedback)

So basically the idea is to put together the joystick and some extra inputs, define a standard communication protocol and implement the relative software.
The extra input will be a potentiometer (for changing some user defined value), microswitch to make some action buttons, dip switch to set some digital values.
The robots will be able to communicate back some data, that the controller will use to light the leds and eventually to buzz the buzzer.
The structure will be based on a board of plexyglass (13 cm long) with the joystick and potentiometers glued over. Yes, i usually hate to glue stuff, since i like to recycle my robots, but the controller will be universal, and there's no many other way you can use a thumb joystick anyway.
Below the plexyglass, at about 1 or 2 cm i'll attach the perfboard which will contains the circuitry. I have yet to decide wether to use 4xAA batteries or 1x9V batteries to power the stuff. The 9V can maybe be inserted between the two boards (making the controller smaller), while the 4xAA would need to be attached below. I'll have to check the energy budget since the XBee pro module can consume some nice current.

For the "brain", i decided to go for a "naked arduino", that is, an atmega168 chip with Arduino Bootloader without the board. The circuitry needed to run the thing is very simple. It will also use much less space, apart from being cheaper. Of course it require more work, but that's a good thing for me :P It will not programmable "in circuit", but once the software is written, it shouldn't change that often, if ever.

So, stay up for updates :)

Killer bot

2009-02-16T13:34:00.013+01:00

Here's the new project i'm working at. It's a rover with autonomous or remote control, which will be equipped with a wireless camera, various sensors and with a lot of free space to add more features in future.
The case is based on an old PC case, which i adapted to the use (i made it a little smaller). Many other pieces are from previous dismantled projects, to cut on the costs :)
The rover can be controller with a PC, but i'm also planning a custom handheld controller.

The name is probably temporary :P

Here's the (current) part list:

Gallery

Here's the current internal of the robot. The space below the board is for the battery, the whole 1/3 on the back is basically free for future stuff :) You can see all the board, including the XBee module

This was the computer case before working on it. I cutted it to make it less tall, drilled the holes to attach the motors and the base plate.

Here's the base plate of the robot, with some test for where to place the stuff.

Here's the finished box, you can see the precisely drilled holes for the motors, the indentation on the bottom plate to house the motors: all the metal working that costed me quite some evenings :) Ultimately, putting the battery on the back proved to be a bad idea: too much weight on the fragile rear wheel, and too little on the front ones (they were started slipping). So i raised the electronics board and put the battery under it, at 2/3 of the deck.

Repairing the EMG30 motor

2009-02-16T12:12:00.003+01:00

Some days ago, while maltreating one of my EMG30 motors for structural testing (ie, forcing it to fit where it cleary wouldn't) i accidentally snapped off a wire. (imprecation)
So i removed the black plastic case and exposed what it looks to be the hall effect encoder (the round stuff in the center should be magnet).
I noticed that the wires are soldered *under* the PCB, but that would require removing it and it was heavily soldered.. So i said, whatever and soldered it on the top. Thanks to my superhuman soldering skills, i was done in no time :)
I had to cut a little of the black plastic cap to fit the wire as it was higher now, but no problem.

Then i wired it, tested and yeah, it worked! :)

Liquorice xbee box

2009-02-16T09:24:00.005+01:00

Well, for the PC end of my XBee connection, i hade to find a box for the Explorer USB, so i watched around and found a nice tin box of liquorice i consumed some days before.
So i took my trusted drill, made four holes and then opened a small window with my dremel.
Then i screwed the board, snapped the XBee module, and presto, a liquorice flavored XBee module casing :P

XBee test successful :P

2009-02-15T12:31:00.002+01:00

Yesterday i finally received my sparkfun order with th XBee module i was waiting (i ha purchased two previously but unluckly one of them was broken).

So after CAREFULLY handling the module, i went throu this fine guide to update the firmware and configure them. I patched up a delphi program to send directional control to the serial, and in no time i was controlling y new robot from the laptop :P

One of the Xbee is connected with a ladyada adapter, the other with a sparkfun's XBee Explorer USB.

My first, simple robot

2009-02-13T14:10:00.011+01:00

Here's my first robot :)

It's based on "start here" design on letsmakerobots.com.

This is actually some of the simplest robots you can build: require little soldering and very little knowledge. Indeed, i had zero knowledge on electronics when i made this.

Part List:

1x Picaxe 28x1, the "brain" of the robot
1x Motor driver (L293D or SN754410), which controls the two motors
2x GM9 gear motors
2x GMPW Wheels
1x Sharp GP2D120 sensor, it tells the distance from an object
1x Superbright LED (and the relative resistor)
1x Battery holder
2x Microswitch, similar to this one.
Various nuts&bolts, burnt CD, etc

It's held together with a solid structure based on nuts and bolts (as you can see from the pictures) and CD plates. A wooden cube is the main attachment for all parts. I like this design becouse it's completely disassemblable, nothing is permanently attached. Also, it's quite strong (well, for a small robots, anyway :P)

I also added a ultraluminous led, it make a very bright light cone, give great effect when the robot turns :) The led is mounted on the head near the IR sensor, along with it's resistor. It's actually connected to G and V, since i don't have a transistor lying around, so it's always on then the robot is on.

Welcome

2009-02-13T13:33:00.002+01:00

Welcome to my blog :)
I'll write here about my electronics / robotics / software projects.