Don’t worry about the color of the resistor array. It should be the right chip if you bought the SHR bundle. If you are not sure, try measuring with a multimeter for resistance from one pin on the chip to the pin directly across the chip from it. It should read about 330 ohms. No multimeter? Try connecting one pin to the positive wire from the battery pack and then put an LED on the opposite pin. The other side of the LED goes to the negative side of the battery pack. Make sure your LED is inserted the right way (flip it if it doesn’t light). If the LED lights nice and bright but doesn’t smoke, you have the right resistor array.
You mean there is no cable, right? Solarbotics stopped carrying it, so the SHR bundle doesn’t include it anymore. You can order a 3-pin JST cable from another place, like this one. Or you could make your own cable from three of the female-female jumper cables included in the bundle. Just be careful to wire the IR sensor the way it shows in the tutorial. If you wire it up backwards, you will ruin your sensor in a moment, and it will silently die.
A nice soldering iron is good to have, but soldering skills are more important. I’m using the same cheap Weller iron I’ve had since high school, and it works fine. You want a fine, chisel point tip. Check out the LMR Primer page and scroll down to ‘Soldering - how to solder’ link. A few minutes time watching a good video on soldering will save you a lot of headaches.
Thanks, my resistor array should be fine but my other two problems are still problems. Whith the 3-pin JST cable I live in australia so the cheepest shipping I can find is from Robot Gear and that’s like $6 and the female headers are way to wide. I’ve checked the soldering video and I realised that my soldering iorn probaly isnt getting even half of my needed heat so if anyone can suggest a good but not to expensive brand that would be nice.
Like I said, my crapy soldering iron works fine for me. It is a Weller 25 Watt iron with a fine point chisel tip. Not that I recommend this if you are going to buy one. However, If your iron is not getting hot enough, it may just need to have the tip cleaned and tinned.
There have been quite a few discussions about what soldering iron (or other lab tool) to buy. Here’s a few links to review.
I’ll try soldering my IR sensor, thanks for the tip but with my soldering iorn when I took a closer look, the tip was covered in burnt plastic (oops). I don’t have anything to clean my soldering iorn but my kit did come with a spare tip so ive swaped it and I promise not to melt any more plastic battery holders when I’m bored ever again.
Hey Nano, we owe you a quick apology. Our supplier stopped making the sensor cables, so we were kinda left out in the cold. We adjusted the kit price so that you wern’t charged for it, but you didn’t quite end up with all the stuff you need. We’ve finally found a new supplier and have the cables on the way, but it isn’t quite in our hands yet. We agree with ignoblegnome - SparkFun is probably the way to go, they’re pretty great guys and the part is well priced.
Or, if you’re feeling adventerous, you can make your own connections out of a 3-pin servo cable (again, like ignoblegnome suggested. Darn it man, you totally beat us to the punch with this post!). We’ve made our own guide here that’ll walk you through the process. Hope that helps!
Whoops - I seems I wasn’t as clear as I should’ve been with my explanation. We do not include the sensor cable, but we do include a 3-pin servo cable, specifically for the purpose of modifying them for connecting them to the sensor. Sorry for the confusion, everyone!
Analogue or Digital work if you just move the wires around
See my blog post for a simple trick to swapping wires in those connectors. I am working on a graphic to show how easy this mess can be turned into a great little robot. I cut up a five pin connector that fit and sanded it down with a Dremel sanding drum. Works great.
Now I have 30 analogue(I did not see it was a set of 10 each) and 3 digital that DFRobots threw in for free because of my confusion over the cables and the delay of my order waiting for a set of female to male jumpers on back order.
Anyone in the L.A. area need analogue cables? JST 1-Blue, 2-Black, 3-red connector Blue-Black-Red
The Digital JST 1-Green, 2-Red, 3-black connector Green-Red-Black
And the JST connector is too tight and needs to be sanded just to fit the Sharp ranger. But, it works after you swap wires around. What fun!
I want to build a robot kind of like yours but with some modifications. It will have 4 motors (and wheels), a SRF05, and probably a LED or something to make it look nice. Is it the same programing with the SRF05 or different? If different, send me a e-mail how to program it please. And, does all that power fit into 4 non-recharchable AA batteries?
I want to build a robot kind of like yours but with some modifications. It will have 4 motors (and wheels), a SRF05, and a LCD screen. Is it the same programing as the sharp IR to program the SRF05? If different, send me a e-mail how to program it please. And, does all that power fit into 4 non-rechargable AA batteries? And ofcourse, I’m using all the other stuff needed from the kit
The SRF05 will require different control than the Sharp IR range finder, but there are plenty of programming examples for the SRF05 on this site, just search for it.
To use for motors, you will need an additional dual h-bridge motor driver. The Picaxe 28 project board only supports one L293D motor driver, so you will require an additional motor driver chip on an extrernal board. Keep in mind that each motor needs two digital outputs to control it bi-directionally. So for four motors you will have 4 x 2 = 8 digital outputs used just for the motors.
For the Picaxe 28x1, that is all the outputs you have by default. You will have to reconfigure some of the digital inputs as outputs. Read Picaxe Manual 1, appendix E for information on how to do this. You need a digital output for the servo.
There are some examples on this site for interfacing an LCD to a Picaxe. Also read Picaxe Manual 3, the section on Advance component interfacing for options on using an LCD with a Picaxe.
If this is your first robot and you are not that experienced with electronics and programming, I suggest you start out with the basic Start Here design. You can always expand your design later. However, most people find that building the start here is an excellent learning experience and provides plenty of challenge at the beginning.
I made the robot following your tutorial, but somehow the robot just turns its head (with no obstacle in front) and make a left turn, and repeat. When debug it, it’s showing me the value of b1 is at a constant 135, (if I try to put something in front of it sometimes it changes to 125 ish then back to 135 (in a randomly manner). Did I accidentally fry the sensor? Or did I connect the wrong cable? (I solder the black red and white cable directly to the pin on the sensor in the same order as the pic which is red black and white, and they are not touching each other or other metal)
I am from south India My neighboring village is suffering from mosquitoes
So I want to help them by making a project with picaxe or other ic .I want rotate a dcmotor after five days what will be the code if I use picaxe 28 X1 (in this project i want place water in a bowl .Mosquito lay eggs in it they will hatch in to larva .in 5 to14 days larva will be mosquitos,before that (after 5 days) the water in the bowl should be filtered to 2nd bowl and kill the larva in the 1st bowl and again place the water again to 1st bowl. with this project I think I can kill 1000 s of mosquitoes and will be a great help to the people.
m really happy and excited to tell that iv completed building my first robot, but at the same time in sad as its not working properly. Actually its behaviour is some what different,the main problem i see is its not moving as shown in the video on start here page.
iv seen many other ppl who made this and its just working fine but this one is like moves a little stops but the servo keeps rotating left and right. i tried testing every part individually and they work fine but if i program them to work simultaneously they dont work properly. it happens like the servo rotates left and then right and the wheels just rotate. some times i turns and stops. one thing which continiously keeps working is servo and IR sensor!!!
I’ve now solderd my robot together (I may not have the best soldering skills but i’m getting better) and i’ve tried to program it but I keep getting this message saying: serial port error - port not present or already in use. I think that means that I need to download the picaxe to my computer but me and my dad tried that and we don’t know how. If you can help me please do.
ps: am I meant to be using the PICAXE programing editor, if not what should I use.
Have you followed all of the instructions in the section of the tutorial, ‘Break out Software’? You need to install the Picaxe Editor software and the driver for the Picaxe programming cable.
Which Picaxe cable do you have, a serial or USB? When you plug in your cable to the port on your computer, it should be recognized if you have installed the driver correctly following the instructions on Picaxe’s web site. For a Windows computer, you can check the Device Manager under COM and LPT ports and see if your cable is identified.
It is possible that you have the sensor connected incorrectly, or that you accidently fried the sensor. You may have overheated it while soldering if you kept the heat on for an excessive amount of time. Another way to fry the sensor is to connect the power to the wrong pin.
I recommend that you carefully check all of your connections. Then isolate each section of code and test it separately.
First test the motor. Can you make your robot drive forward by commanding the correct pins HIGH and LOW? Can you make it turn left and right?
Now test the servo all by itself. Can you make it turn the head to look left? Move to center? Look right?
Lastly, the sensor. Test the sensor as described in the post using the debug command. If you do not get readings that change relative to the position of your hand as you move it closer and further in front of the sensor, something is wrong. Double check your connections. If you own a digital camera or camcorder, turn off the lights and look at the sensor while the robot is powered on. You should see a blue light from the IR LED on the sensor, which the camera can detect although your naked eye cannot. If that is not working, your sensor will not work. Even if it is working, it only shows that the IR LED is lit. The IR detector or other electronics could still be damaged, or you could just have a connection problem. But if there is no light then it certainly won’t work.
I recall one person on this site who accidently fried their sensor. They ordered a replacement, but in the meantime they found themselves a bump switch and wired that in, learning how to use one and alter the program to work with it.
