Let's Make Robots!

Md23: the revenge

Hello :) I'm here again to annoy you with my md23 :)

So, a new board has arrived, but now the question is: how do i feed it without possibly burning it ?

I was planning to buy a 12V lead acid battery for the robots, are there some issue i should know? something like the fact that it gives 15V when you least espect it ? :)

Btw, if i would like to use the 12V unregulated adapter, how could i "regulate"  the output?

Also, could i use a PC power supply? It should be switched-mode, right ?

MCU for custom i2c motor driver

Ok supposing that i want to make my own motor controller, i'd like it to be controlled by i2c. What microcontroller could i use that can be used as i2c slave? Afaik, picaxe can only work as master, right ?

Possibly someone that doesn't need an hardware programmer :)

burnt md23 :(

Ok, i burnt my brand new 50€ worth MD23 motor controller. I'm deeply desperate... I was all excited about its arrival with all the RD01 kit, i was all happy about the incoming testing and building and having fun with it, when suddendly all the magic smoke came out of it and dispersed for good. :(
BWAAAAAA :( i'm so saaaad :(

Sniff, ok.. So i'd like to at least have some idea of what happened, becouse i have none.. How can it happened ?
This is the chip that smoked:
37369566dded3f0378c85b4cb5b4b177.jpg

Servo and picaxe: need resistor ?

hello, i'm trying to use a servo with my picaxe. I tried it on Arduino before, and it worked just connecting the pins at the right position, without resistors.

now i just connected the same way on the picaxe, and it doesn't move.. I then remembered that in the "start here" project, a resistor was used.. So the question is: is it necessary? why do i need a resistor? and how do i wire it ?

Another thing that is probably messing up.. i have the darlington chip there.. shoud i remove it?

 

thanks :) 

Some considerations about Letsmakerobots.com

Ok, let's start saying that i love this site and i'd like to see it grow. So here comes the things i don't like or that could imho made better. They have mostly to do with the use of drupal and its "flatting" of contents. IE You can't easily say whether you're looking at a robot page, at a forum page, at a blog entry etc, and i find it quite discomfortable.

Robotic Airship, some ideas :)

So i was looking at some flying robot designs, just out of curiosity. I ruled out helicopters and planes: they require too much precision in crafting and are too complex.. But alternatively an airship could probably be built :)

I've read on wikipedia that a square meter of helium can lift about 1 kg. A square meter means a big balloon, but a Kg is plenty of weight for electonics!

If you use light components, you can probably stay under 0,5 Kg or even less.

A Playstation controller as remote controller

So, suppose i have a couple of those wireless radio serial modules.. I'd like to hook the receiver to my robot, and install the transmitter on a playstation controller. Now, given that i can make a protocol of my own, the question is: how can i interface with the controller buttons&joysticks ? i'd like expecially to read the analogic joysticks.. is it hard ? How is it build inside ?

Robot with Tracks

Hello, just a question to all who made a robot with the tamiya track set: did you implemented any kind of track tensioner? or just calculated the size and "stretch" it over the sprokets&wheels ?

Arduino and I2C LCD

(cross posting with arduino forum.. no answers there :(( )

Problems with i2c (and an LCD display)

So, i just wasted an evening trying to make an LCD with i2c work with my picaxe.

I connected the SCL and SDA of the board to the other end on the LCD. (of course not crossing them :P)  BTW on the picaxe the pins are: Digital input 3 = SCL; Digital input 4 = SDA, am i right ?

If so, other question is: do i need the two pullup resistors ? i've read somewhere that they're already there on the board. But if so, the pin should be high most of the time, shouldn't it ? testing with my voltmeter reads 0V. 

PS i have the picaxe 28x1.