Wednesday, May 4, 2011

Back to work...

Sorry for the delay in getting to the next project but I can now share with you why I've been a little tardy. I was asked by Make: to host a new video series called "The Latest in Arduino," and it's taken a bit of my free time to get it rolling, but now that episode 1 is out (and raw video for episode 2 is submitted) I can get back to the Beginning Arduino projects.

Before I move on to the robot project, I needed to solder up the MotorShield. It wasn't difficult, but look close and you may see an error I made... it's not critical and I can still work with it, but it'll always stick with me as a reminder to go EVEN SLOWER when soldering up these shields!

Now that the MotorShield is done, I need to solder some wires to the motors on the robot base... so I'll try and tackle that tonight so I can get another project completed before Friday.

I'm also going to be attending Maker Faire in San Mateo, California, in a few weeks... if you're going to be there, come by the MakerShed tent - that's where you'll find me. I've been asked to tag team between my own booth (showing off the 3D Printer that goes with my new book "Printing in Plastic: Build Your Own 3D Printer" with my co-author Patrick Hood-Daniel) and a booth where visitors can test out the MintDuino and wire up a few cool things. Should be fun.


  1. I built an Adafruit motor shield too. I've set it up to run my little tank robot. The problem I have with it is that it sort of blocks off all of the other pins of the Arduino and it is difficult to tell which of them are still available to run sensors, indicators, X-Bee radios, etc.

  2. Great Blog so far!! i am trying to catch up with you (I just completed project 24) I too missed the little ground wire but thanks to your blog I was able to get it up and going quickly. keep up the good work!

  3. Hello all. I'm loving this blog! I've followed along with all the projects so far and now I've progressed a little bit ahead. I'm working on project 30-line following robot-using the Adafruit motor shield too. I've modified the sketch to work with the Adafruit motor shield library and I've breadboarded it all up. Everything seems to be doing what it should be doing. The calibration routine seems to work and the DC motors change speed according to variations in light hitting the LDR's. There's just one (major) problem: The three LED's glow very feebly. They just will not put out full luminosity. I'm using pin 2 (which is one of the few output pins not used by the motor shield) to drive the three LED's. I tried using my Arduino Uno without the motor shield attached but the problem with dim LED's persisted. I've tried using just one LED, thinking that maybe I'm drawing too much current but that didn't help. I tested the UNO board just to make sure I hadn't wrecked it. Using the same Pin 2 and a simple LED flashing sketch the UNO board is capable of driving my white LED at full luminosity. This works fine so I'm certain that the problem isn't with the UNO board. It must be something with the Motor Shield Library. Does anyone know a solution? I'm now ready to assemble the line-following robot but I suspect that the dimly lit LED's just won't be adequate for the task. Maybe I'll have to give up on using the Adafruit Motor Shield and get the one used by author. So close yet so far.......

  4. Doh! Rank amateur mistake: Forgot to define pinmode as output. Working fine now. LED's bright and beautiful! Next step--- assemble robot platform and put rubber to the road!

  5. Never mind. Amateur mistake. Forgot to declare pinstate as output. LED's glowing like gems now. All working well!

  6. I'm sorry to see that this site has gone dormant. I'm guessing that you lost interest and moved on to new things. Still, I was hoping to follow along as you worked out the kinks. Mr. McRoberts text seems to be full of serious typos and I've had to work through all the errors myself. Too bad that APress doesn't have an an online errata page like O'reilly books (Arduino Cookbook) does. Oh well, I suppose that I'm learn more by working through the problems this way.

  7. Hi, EJB.

    I was at the Mini Maker Faire yesterday in Atlanta and I remember saying to myself... "time to get back to the Arduino blog."

    I've been VERY swamped with (paying) writing work of late and just never can seem to find a big enough chunk of time to get back on a roll... I need to do it.

    Thanks for the note, and I think you've lit a fire under me to get back to it...

  8. Hi, I'm looking to start learning about micro controllers and I've heard Arduino is the place to begin, I've done a little C in the past but what I want to know is should I go for an Arduino Uno or an Arduino clone I know the price isin't that much less but I a student!

    Thanks in advance.


  9. Kev, The difference in price between a "genuine Arduino" UNO and the clones is so little, that it is really probably worth it to just spend a couple of extra dollars and buy the genuine article. At least for your first board. Think of it as paying back the people who put the blood, sweat, and tears into getting the entire Arduino project off the ground.

    Many of the clones are EXACT copies of the Arduino and will work exactly the same.

    But others are stripped down versions that have a slightly different form, or leave out ICSP headers, or USB, or some other portion. These are for people who are well practiced with the board and able to knowingly trade off capabilities they do not need for a specific project for a few buck's savings.

    As you gain more experience, eventually you just build your own support circuitry around the Atmel chip and skip the Arduino board.

    But for getting started, I think it is well worth your while to buy a genuine Arduino, and better yet, one of the starter kits from Sparkfun , Makershed , or Adafruit All of these kits will get you up and running and well down the road to understanding Arduino.

  10. Jim, I am hoping that when you approve this, you will also check out the following link and then do what you can to forward this message through the maker/hacker/technical blogger community.

    While I am aware that not all techy types are into model rockets, in the model aviation community, we have been pushing back against demands for greater regulation of hobby supplies for years and as these regulations spread, it is becoming more and more costly to obtain hobby supplies. Imagine if restrictions spread to micro-controllers, sensors and output devices merely because of the potential that someone might devise a dastardly use for them.

  11. Did you one better, ctdahle:

    ... plus sent my own email.