Let's Make Robots!
homemade PCB through the heat transfer method and muriatic acid + hydrogen peroxide etching
There is an available pletora of how-to description regarding home made PCB boards. These are built around three different core trace transfer methods, the … Read more

feasibility of DIY wireless headphone kit

So, I was searching the market for what my wireless headphone options were and got quite disappointed.

As it seems, wireless used is either IR, RF (on the FM/UHF band) and Bluetooth (also 2.4Ghz seemingly working in the router's norm).

IR ... needs line of sight, small range...
RF... prone to interferences
Bluetooth... small range
2.4GHz... some reviews said they interfered with the home wireless routers


Smart trashbin

Well, I only took a quick peek but this bot sure looks nifty. And if my assumption that the kinect is used as a sensor for the implied autonomous part of the project and it's not some guy off-camera controlling the trashbin then it's even niftier. (I'm too lazy to do any further verification :P)

Interrupts and wheel encoding... a beef with...

EDIT (June, 25th 2012):

The headache just doesn't go away...

Despite the photo below now I have a tube of black heatshrink shielding the sensor. It increase the analog output, for both cases (black and white). Regardless, the behaviour remains the same as without the shield when I move unto digital pins. I've been trying to deal with debouncing for the past couple of days with no luck.

// Playing with encoder digital readings


const int sensorPin = 7;


int lastColor;

int currentColor;

int count;

Comming to grips with arduino, bootloaders & ISP...

UPDATE/ADD-ON: June, 6th 2012


For the sake of argument, let's pretend I'm a bit thick in the head and also that every day is a Monday for me.

Being a bit reckless in some respects, and hating the shipping wait times, I've ended up ordering a few ATmega324 chips, so the current Atmega328P-PU tally is:

- 1 blank

- 1 w/ the duemilanove bootloader (supposedly, but I believe it so)

- 2 w/ the uno bootloader (which I have some heavily suspect might be blanks or w/ the duemilanove bootloader instead)

Piezo elements and their Resonant Frequency

Ok, I was looking forward to stock up on piezos. Not particular plan in mind at the moment, but I just want to have them around when I need them. (shipping times are bothersome) So, I was looking for me most versatile ones.

Then, I've realized that I know next to nothing about piezos, but when looking around on ebay, what it seemed to vary was the size of them alonside with the resonant frequency.

So looking for resonant frequency of the piezos I've found:


[ALMOST SOLVED] HC-SR04 still giving me grief...

June, 7th 2012


- Updated schema.

- Segregated power supplies of arduino + sensor
- Added 0.047uf caps to the motor leads (one per lead) grounded by the casing.

- Motor + servo power supply changed to 4 AA rechargable batteries.

- Arduino + sensor when powered by USB everything seems to work fine, except the sensor is a bit slow to respond but that surely it's the code's fault.


- Pending issues:  

Understanding servos...

Well, I'm trying to learn servos so I'm toying around a micro servo 9G.

I'm using an arduino one board and the following code:


#include <Servo.h>

Servo neckServo;            // Define the Servo object

void setup()


  neckServo.attach(10);     // attach the servo on pin 10 to the servo object 

  neckServo.write(90);       // "favorite" default position



void loop()



Semi-loose thoughts from a total begginer

I'll be using this blog entry to kind of introduce myself, and gather/organize my thoughts and plan my way into making my first robot but also receive any advice that might be given to me.

(relevant) background:


path of interests (line of thinking) that led me here: