Let's Make Robots!

How to use two analogue devices with only one analoque input?

For now it's theory, it's for a future evolution of a future project (yeah i know that's two "future")
Ok actually i'll need 3 analogue inputs (one SRF05 ultrasonic rangefinder and one 2-axis accelerometer), but the 18x picaxe chip has only two. So basically, i need to find a way to share one of the inputs. As i won't need to read the all inputs at the same time, maybe it's doable.

So two ideas came to my mind, each one with its pros and cons.

First idea : a SPDT relay.

With that, two solutions :

It soon is time to have another LMR skype social weekend!

Yes, yes.

Will you get drunk, and join in? Theme will be telling people long tales about what you do when you are not making robots.

No one sticks to the theme anyway.

However, the word "Hello" is prohibited, anyone saying it will be kicked off the line.

Do you have a fast connection, can you host?

Salvaging Parts

Hi all, 

I'm new here and wanted to know What would be good appliances or computer parts to salvage robot related parts? (motors, gears, electronics)

I saw someone take the HDD's motor, but it seems the use of it is a bit complicated, and I'm a complete noob.
Are all the motors in HDD's like the one he used or does it vary?
Thanks in advance,

windscreen wiper motor with three brushes...

Hi all,

I always thought/assumed that brushed motors had two brushes in them. Mine has three. How does it work?



Motor Driver question


i'm trying to build 'start here' robot using  arduino as the brain 2 gear motor as the driving force.one of the forumer has point out to me that i need a motor driver to control the motor for forward and reverse movement,

my question is(sorry if sound stupid) do i need 2 motor driver for the 2 gear motor or 1 motor driver is enough.and how to use this motor driver.

thanks for the help.truly preciated


Servo Control with PICAXE-08 (NOT M)

One for TofuRobot.

 1.    The electronics:-


The Diamond on the left is the Picaxe pin, I normally use a resistor 100-200R just to protect the Micro just incase of short or plugging the servo in backwards (there are two types of people using servos, those who have plugged servos in backwards and those who are about too!).

Unable to connect

Have u all ever managed to find out ; the cause of the PICAXE28x1 unable to connect to the pc/ download the program into.

I got my first picaxe few weeks back and did my first start here bots.

Everything goes fine , got it running well. here and there.


Now i unable to download a program in. It say :

check the power supply to the board,

check if its connected to the pc from the download cable,

Press and hold reset till the download bar appers to reset the board.


None of this works.

NiCd discharge question

i have any questions about the topic


when a nicd cell have to be recharged? i am taking about voltage... 1,15v? 1,10v? 1,05v? 1,00v?  per cell

i have a 3xcell batt pack in a bot , the system self recharge when the voltage reach 3,4v, so 1,13v  per cell

is it an insufficient discharge? which can bring to lazy effect?


assuming that X is the ideal voltage per cell  to decide to recharge..... have i to read X  when the battery is under load or when it isunder no load.