Let's Make Robots!
Add sound to your robot! Piezo speakers elements can be driven directly by a PIC output, and are nice and small. These are two varieties I picked up at the … Read more

Servo glitch when downloading from Picaxe Programmer

I seem to be having trouble with downloading programs from my Picaxe Programmer to my Picaxe-40x2. A lot of times I get communications faults and have to reset and try again.

Worst of all, sometimes these errors are accompanied by somewhat distrubing behavior for the bot itself. It seems like all the servos are being forced to turn very far to one side. One servo (a DAGU mini) in particular seems like it is trying to turn itself past its limit.

Ignoble Idiocy

"Those who cannot remember the past are condemned to repeat it." - George Santayana

mistake_0.gif 

Nobody's perfect, least of all me.  Here I intend to record some of my roboting mistakes for my own good.  Perhaps you can learn from my errors, or even contribute your own.

Latest Update: 2010-02-04

Dual Y-Bridge (was One and a Half H-Bridge)

I had an idea tonight that is either inspired... or stupid. Please help me determine which. ; j

I was thinking about using one of my new Picaxe-08 processors for a project. They only have 5 I/O ports, three of which can be either an input or an output. However, for my project, I wanted to be able to control two motors and two sensors. Since traditional dual H-Bridge designs would require four processor outputs to control two motors with forward and reverse, that would leave only one I/O port left. Boo hoo.

Brings good tidings... until nightfall. Then it signals the mothership for the invasion!
Merry Christmas or the secular, religious, or pagan holiday of your choice. I love this little Christmas ornament from Instructables, so I decided to build some … Read more
Drives over most stuff, occasionally flips over.
Using a
Mr Mountain Monster (MMM) was originally named Mr Suspense because his main modification to the Mr Basic kit from DAGU is the suspension and flexible drive system. … Read more

Mr. Suspense

Just starting a build blog for the Mr. Basic Challenge II.  When I get some more progress I will post pics and make a robot page.

I'm still developing ideas, but I liked Gareth's work on a suspension system for the original Mr. Basic Challenge, so I'm starting with that.  My suspension will use steel cable instead of polymorph for a flexible power transfer system.  Ultimately,I want to try a four wheel independent suspension, but I will start with the front axis being on one suspension platform and the rear on another.

The "Uncanny Valley" of robotic appearance

I came across this Wikipedia article about how humans can have a negative reaction to robot's appearance as it begins to approach a human realistic level.

Noisy LM386 based audio amplifier

Inspired by this post from Salvage, I ordered a couple of gameDR Smack Talk for the XBOX units. The volume is way too low to drive a speaker directly, so I need an audio amplifier.

That led me to this post from Calculon320 on building an amplifier with an LM386. I breadboarded the audio amp, and it definitely amplified. However it also added a lot of noise. It could be cleaning it all up on a perf board would fix some of that, but it is very noticable.

Practical question about servos and capacitors

I have read in many places on this site about using capacitors to reduce motor and servo noise. I am now using 0.1 uF capacitors across the leads of my motors as standard practice. I'm also using 470 uF and 0.1 uF capacitors around both sides of my voltage regulator. As yet I haven't tried applying a cap to a servo, and I have a quick question.