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unix_guru's blog

Using the Arduino PID Library for precise position control of X and Y axis on RepScrap printer

I've updated the test code I'm using to manage my X and Y axis DC motor / linear encoder closed loop controller.

Further Progress on framing my RepScrap 3D printer.

Well, this is what the RepScrap looks like today.

 

My Repscrap: DC motors and rotary encoders for Z-Axis too?

 

 I took a few pictures this morning, to give me something to think about while I was at the cottage for the weekend.

Controlling a Raspberry Pi / Arduino Bot from the Internet Part 3 of 3

This is part three of a three part Series to explain how I control my BotTwo semi-<a style="color: #888888; font-size: x-large;"

Controlling a Raspberry Pi / Arduino Bot from the Internet Part 2 of 3

This is part two of a three part Series to explain how I control my BotTwo semi-Autonomous Robot from a webpage on the Internet. 

Short post on Successful data out of OSLRF-01 Laser Range Finder

It's late and I'm going to bed. My eyes are blurry, and I've got a headache... but!!!

I'm getting reliable (for the most part) Distance readings out of the OSLRF-01 as evidenced here in my putty dump.  The "ACTUAL" distance to target was in fact 2.67m.  I've got a fairly consistent reflection or ghost at 0.67 and few more stragglers that I will work to filter, but I'm quite pleased.

Prototype of OSLRF01 Arduino Scanning LIDAR (Under $150)

I've finally got pictures to show off the OSLRF-01 Open Source Laser Range Finder.  I've mounted it to a sturdy servo, and am running both currently with An Arduino FIO ... simply because that's the only available Arduino I have at the moment. 

I am also getting boards made up around the ATtiny84 that will sit as a daughterboard on this unit.   But the FIO prototype is to help me get functional code working NOW...

I just received my OSLRF laser Range Finder!

So I received this awesome package in the mail yesterday from LightWare Optoelectronics in South Africa.

HMC6352 Compass Module in Continuous Read Mode

I have a need (desire?) to use compass heading as part of my PID loop to keep my rover heading true.  Using my well established trial and error coding technique, I was unable to get a sufficient sample rate from the HMC6352 Compass module using code I pilfered.. er... borrowed (I plan to give it back!) from the Interwebs.

Bottoo or is that Bottwo ?

Well..  I'm just starting out on my second Robot.   I learned a lot about what to do, and more specifically what NOT to do while working on Robbie.

 

This new one will of course be based on the premise of Robbie, Raspberry Pi making the decisions, planning. mapping, etc.. with Arduino's doing the mundane work of running motors, reading encoders. 

Royal AP8000 8000mAh USB battery for $12 !!!

I just visited one of Costco's Clearance Outlet stores nearby, and found this LiPo battery pack for $12!  Just because it was out of it's packaging!

5v 2.1A out, wich charge level meter on front panel.  Weighs about 12oz...

Had to buy two of them  IMMEDIATELY before someone came to their senses!

It retails at Costco for $40, which is still a great price for LiPo  8000mAh here in Canada. 

Looking for ideas on a I2C Pan/tilt stand-alone sonar

This quest to build a stand-alone I2C pan/tilt range finder controller started with an article here by Ladvien.  In    http://letsmakerobots.com/node/39130, Ladvien explores using an ATtiny85 (84) as an I2C motor controller...

And in http://letsmakerobots.com/node/39222,   Chris the Carpenter   gives us an awesome pan and tilt code example... so...

"Do not average your Max-Sonar results..ever!" who knew?

I've apparently been mistreating my MaxSonar EZ-1.   I can't find where i stole.. er... borrowed my idea from for averaging a series of responses to reduce the inconsistencies, but I was looking up some information on the Arduino pulseIN() timeout (Thanks Oddbot!) and came across http://playground.arduino.cc/Main/MaxSonar   ... Yeah... I know it should have been one of my first places to look, but...

Two Arduino problems fixed in one day! Halelujah!

 I've been procrastinating on two problems that I've not been able to resolve  - or google an answer for in my code.

 

1) Slow response in the Serial.parseInt() function... yes google gave me lots of people with the same problem, but I finally found a reference to  Serial.setTimeout()  ... well what do you know...  I set Serial.setTimeout(50)  in my setup... and low and behold...

  SNAP RESPONSE now!!!!   

 

Finally got a "live" Sonar screen in HTML5 canvas / Javascript working

Prefacing everything i do with "I AM NOT A PROGRAMMER"...

Ok, so it's nowhere near perfect, but I thought I would post the code here in case anyone else wanted to tinker.

Web Control page for Autonomous Rover

 

The sonar.php  file which displays the instrument expects it's data as a JSON encoded data set in the form of:

{"ardtime":"43942","pan":"25","radius":"117","heading":"38.6"}

The 3 'R's' - Rethinking my Requirements for a Rover....


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The case for lurking on LMR before starting on a large (ish?) robotics venture...

Ok... so let me start with... I've been humbled by the sheer simplicity with which some of these bots on here are made.  Functional and clean.

 

The one article that has made me rethink my strategy the most is  Oddbot's article Pushing the limits with encoders