In fact, the item I am writing about is pretty much that thing. It's also very small, in fact it's Teensy. It's available from Cool Components and it's called the Teensy 3.0 board. An ARM chip with some very nice capabilities but also capable of running ArduinoIDE produced software.
Go and have a look at the specifications and then look at the price and you will see why I'm getting enthusiastic about it. Always remember, however, that Cool Components price everything at net price so you will need to add your local VAT or equivalent to the quoted price of £16.71.
This months PC Pro (UK edition) has quite a spread on the Arduino platform with a project based on the Leonardo. It may even have helped me to solve a problem I am having with an 'if----else' loop.
Sometimes, you get so far in a project that you know, instinctively, that now is the time to stop and leave it because if you move on right away you will spoil something. I have had several momentary flashes of inspiration like this with my TagBots and yesterday evening was the latest blinding flash of understanding. I was very keen to investigate how functions operate on the Arduino so I started playing around with some simple ones related to the wheels on TagBot 3 and, after a few minor glitches, I managed to make a suite of functions work from within a loop. That was when I stopped and went quietly to bed. Tonight, I will be looking deeper into the Hub-ee library to see if I can use it for even more accurate movement.
As an aside, yesterday I had to charge up my LiPo battery for the first time. I was astonished at how quickly it came back up to full power even on the standard charge setting. If I have one recommendation to pass on, it is this; invest in a good charger, I have a B6AC unit, and good LiPo batteries and forget all about any other type of portable power. They weigh very little and do so much. The batteries are reasonably priced, smaller and, with a good charger, very easy to use.
I can also report, with the greatest pleasure, that the Creative Robotics shop is now open for business. For a short time it will be for UK customers only but, once thoroughly tested, it will be opened up to the rest of the world. I have changed the links as appropriate on the side panels, shop on the left and main site on the right. The shop name is slightly different to the main company, Createbots. They are not just selling the Hub-ee wheels, they also have the rest of the related products and some bits and pieces for Arduino users.
I spent yesterday evening tidying up the latest TagBot and taking some photos to post here. Then, this morning, I noticed that we have now jumped the 4k barrier so I have decided to also post a short video I made by way of a celebration.
TagBot 3 is a much more stable platform than TagBot 1, due mainly to the slightly larger base size and the horizontal mounting of the Arduino and shield. That has also helped to make for a tidier appearance as I was able to tuck the battery away under the boards. The chassis is, once again, 3mm thick, laser cut and stuck together with solvent. This time, however, I have also strengthened some of the joints with hot glue and that has made a big improvement to the stability of the side panels. The wheels are mounted using a pair of laser cut washers of the same thickness as the chassis panels in order to keep the moving parts away from the chassis itself. This also has the added advantage of letting the plug on the wheels sit very snugly between the wheel and the chassis with no chance of it pulling out. The mounting bolts for the wheels are too long on this version as I ran out of the slightly shorter ones I used previously so I have used 30mm bolts as a temporary fix until pay day.
The view from the rear shows the battery under the boards and the ball jockey in it's tallest build to balance up the chassis.
A word of warning, the spurious wires you can see in most of the pictures are not part of this tagbot. They are a hangover from another test setup that used a 315 MHz remote control system. The TagBots have now outgrown that as I am moving into the area of Bluetooth control instead. Unfortunately, I can think of no way to remove the stuck on board without damaging either or, more probably, both so it has to stay. Note to self, "Get two more shields".
The final icing on the cake is this video of Tagbot 3 running through some very basic commands in order to test stability. It's not very long and was made mainly for my benefit so I have simply added some titles and information to it and pushed it straight to YouTube.
I have now built a TagBot 3 chassis and fitted the electronics to it. Photos will follow soon but, just as a warning, I have named it, "Yellow Peril". I am also now writing my own Android app to control the beast as the various apps I have already tried all seem to be either too simple or too complicated for my needs. My app is just a set of buttons that send a letter to the 'bot by Bluetooth, all the work is then done by the Arduino. Here is a sneak preview of build 1.0
I have, by writing the app in this way, a simpler method of decoding the instructions at the 'bot and outputting to the wheels. We shall see.
I subscribe to many feeds and blogs related to Arduino and Raspi stuff and every so often I see something I feel the need to share with others. Today was my YouTube rollup day and this immediately caught my eye. The Magpie is a simple concept, pin 13 has an LED on all Arduinos. The Magpie has an LED on every pin. Debugging sketches would be just so easy with one of these as you would always be aware of the state of the outputs.
You may only ever need one of these but just think how useful and time saving it would be. Currently, the only place I can find them on sale is directly from the designer, Marcus Schappi, who runs 'Little Bird Electronics' in Australia. Price in Australian dollars is AU$37.95 plus P/P depending on where you live. As this currently equates to £26.00 plus P/P in my currency, it seems a bargain at the price until you check the cost of shipping...................AU$45.00 via the Australian Post Office. Sorry Marcus, much as I would love to buy one, the shipping costs are out of my league.
I have, at last, got around to designing the next Tagbot chassis. I was originally intending to build the second version with a vertical board in the same manner as the first but when I began playing around with the measurements derived from the first chassis, I realised that it would be easier to jump straight to TagBot 3 than try to make TagBot 2 work better than TagBot 1. So there it is, I will, hopefully, be building the new chassis quite soon and then I will have something to run the new software on. I am still having trouble with the Bluetooth connection, I can make it work but not using my parameters. This is proving a major problem and I need to get on with it soon.
Anyway, the new chassis holds the boards horizontally and is slightly wider and a bit longer to accommodate both the boards and the battery pack. The width will also help with the Hub-ee cables as well. On chassis 1, they fitted more by good luck than good planning. The moral being, of course, that we live and learn.
Major inclined plane helical object rising vertically!
I managed to solder in the wrong size of pins on one side of the second shield over the weekend. Removing them was less than easy despite having the correct tools so I now have a damaged shield. I will buy another but, in the meantime, I am reliant on the original shield. So I have disconnected the 315 Mhz board and connected the new Bluetooth board to the Arduino. This all works really well apart from the code I have written. I am obviously making a very big, but probably simple, mistake in the way I am trying to implement the 'switch / case / break' method on my sketch. The sketch I wrote compiles but it just won't do anything when sent to the receiver. The receiver pairs with my phone ok but there seems to be no understanding from the Arduino end. Bah!
