Part two, A new beginning.

Well,  plenty of good intentions but no output to show for it so far.  The main problem was lack of time to begin with and that developed into not feeling well enough to be bothered. The last few posts are just my struggle to keep this blog going. However,  the good news is that I have now begun  to feel much better and,  having now retired,  I have a lot more time to play with. In addition,  I have also begun a new strand of development using the latest tech from China which is both very cheap and very small. I hope to be making some very small self contained, mains powered computers for specialist use soon and I will document the process here as I do it. 2017 may just be a lot of fun.

EUREKA!!

At long last everything is moving again. My new super-duper PC is built and I have finally found the time to re-build my work bench in the attic so that the supports are vertical and it doesn't wobble. In addition, I now have more space than before and, yesterday, purchased the door to keep the cats out when I need to have the door and / or windows open. The new computing kit quite special and I will produce a post about it soon.

Time is relative.............

Any regular reader of this blog will know that I regularly order components from China. People have told me that they wouldn't do that mainly because of the distance and the language barrier. The delay in receiving the goods is also a factor for many. I have always taken a more pragmatic view of the situation. The particular goods I buy are, in the main, only available from these suppliers and are certainly much cheaper. Over the past year or so, the delay in receiving my parcels has increased due to customs activity in Hong Kong as it seems all the post is routed through that bottle neck now.Whilst I have never been let down by a Chinese supplier, the quality of service is variable. Recently, however, I have begun buying from Chip Partner and they have cracked the whole market wide open. They have most of the items that the other suppliers have and usually match prices very well. The best part, however, is their communications. They really go the extra mile when it comes to letting the customer know what is happening with their order. If you want to dip your toe in the water of buying from China, I suggest making them your first point of call.

And a bit more...............................

The voltmeters I ordered from China have just arrived and they are lovely little toys. Very small, not much bigger than the display alone, and only two wire connection. They operate on any voltage from 2.5V to 30V and just work. They cost me 99 pence each and are brilliant. I intend to couple them with one of my homebrew mains power supplies and a DC-DC converter to make up some very useful variable power boxes for my various projects.

PIRfec'

As pop Larkin never said. The board arrived on Saturday and I cobbled together a quick test that very evening. It worked first time. Now I want to build a small unit to mount above the bedroom door to switch on a couple of LEDs to light our way to the bathroom at night. I will document.

This is a very small item and costs very little. I bought one for £2.54 and it's possible to buy a pack of ten from China for even less per item. Just check out eBay.
What is it? It's a very small PIR (infra red motion detector) that interfaces directly to an Arduino and can trigger an action. In this instance, I want it to turn on a couple of white LEDs for a short period.

Oh, the excitement!

When the power  boards arrived yesterday, I began a search for a proprietary method of connecting LEDs to the Arduino as I have a use for the MAX7219 chips I recently bought. After a bit I discovered the ideal solution from the same supplier. Not only is there a board, there is a complete dot matrix display in component form. They have single units to bid on and packs of four for a fixed price. This is the fixed price option here and there are auctions currently for just one.

And another thing.........................

I have received only one comment about the new layout so far, Ian suggested a slightly bigger and thicker font as he is having a little difficulty reading the previous one due to age related eyesight issues. So I have opened up the font a bit and made it bold. 

Power supplies, again.

Anyone who has read this blog on a regular basis will know that I have been working on producing some suitable power supplies for my projects. I have been successful but at a cost. The cost mainly being in my time and the size issues of some of the components. So I have been looking out for a cheaper alternative for some time. I found a very nice looking board with almost the exact specifications and handling as the ones I was building in the Cool Components listings but they sold out as soon as the new stock arrived due, probably, to the very good price. So I widened my net and found a slightly different model for a somewhat higher price and bought a couple of them. Very nice quality but larger than I was looking for. So I kept looking and finally found the original boards on sale from a Chinese supplier for an even cheaper price as long as I bought at least three at a time. I took the plunge and ordered six. The Hong Kong Post Office caused a delay in delivery by a change in their procedure, they now x-ray everything leaving the country, but the supplier, Chip Partner, kept me informed and the goodies finally arrived yesterday. So here they are,

Next move......

I have now widened the template and altered a few minor items, there may well be more to follow but please let me know via a comment if you like or dislike any changes.

Changes in the pipeline

Several changes will be happening to this blog in the next few months. The first is the change of name as now seen above. The old name changed when I moved on from just Arduino to Raspberry Pi as well. Now I am also taking an interest in the Cubieboard I decided that just adding the new product to the name was a board too far. So, after a moment of epiphany  yesterday evening, we now have the name of Tech That!. I won't apologize for the pun as I have loved them all my life and this was just the opportunity I was looking for to insert another one into my life. The second change should happen soon, the old icon will disappear and a new one will arrive. This is only a stopgap until I am able to think of something more suitable than a caricature of me. The third change I would like to make is a bit more fundamental, as I know that a lot of people who read this blog don't have a modern widescreen monitor. Since it's beginnings, this blog has always catered for standard screen monitors. However, with such a lot of new information available, I would like to make use of a different template in order to maximize how much can be seen without scrolling down. If you have any strong concerns about this please contact me as I would like to take this step with your agreement. 

So, to restate the obvious, this  blog now covers Arduino, Raspberry Pi and Cubieboard products and may well also take on other home and educational products as time passes. As an example, I am currently playing with EL wire and hope to be able to interface it with an Arduino in order to produce a copy of a neon sign.

As always, if you would like to contribute to this site please email me and we can work it out.

English: Diagram of electroluminescent wire (Photo credit: Wikipedia)

Close up of El-Wire of a variety of colors (Photo credit: Wikipedia)

Comin' up to speed again...............

It's been a while and I'm sorry for that but life has been..............complicated for the past few months. I'm hoping that it might return to normality now. Since my post about the Cubieboard, I have played with it a bit and begun to realise it's potential. In the same way that the Raspberry Pi will never replace an Arduino, the Cubieboard will never replace the Raspberry Pi. They are different animals and have very different capabilities. I have spent a couple of days playing with some Adafruit Flora RGB LEDs and most impressive they are. In addition, the software is so easy to write for very clever results. I am also currently playing with some EL Wire on Sally's behalf with some thoughts to making an illuminated logo for her.

And now.........The Cubieboard!

I have been away for a while and then began a painful interlude with my back. I am, however, mostly back to the task in hand. I found, by a very strange route, a new board that seemed to promise more than anything else yet tried. So I bought one. The supplier is Cool Components and The Cubieboard is the board. It is small, well made, inexpensive and very powerful for the price. It arrives with Android 4.1.1 pre-installed and  runs straight out of the box. Imagine a Raspberry Pi that is capable of almost everything that a smaller PC can do and you have the right idea.

Yes, that is a sata connection you can see. What you cannot see is that this board also has a line in and headphone out capability as well. Click on the photo to take a closer look.

It's late, and I'm very tired, but........................

I finally persuaded my sketch to run correctly. I now have my two TagBot 3s reacting to obstacles and 'bouncing' when they can't move forward. I'm using the new type of IR detector that simply outputs HIGH when it detects something at a pre-set distance. Coupled with the Hub-ee wheels,this is a very self contained and simple mechanical set up and the script becomes almost as simple too. The basic sketch is as below, the various movements are in functions (forward and bounceL in this instance). Now I have the basic system working to my satisfaction, I will begin to refine the functions first and the loop next. It goes without saying that the sketch at present is very crude and not much more than a proof of method but I would ask you to remember that I am teaching myself this language as I go from books that don't always explain what I need to have explained so I am working on a hit and miss method of writing my code. Nonetheless,I am learning!

#include <HUBeeBMDWheel.h>

  HUBeeBMDWheel leftWheel;
  HUBeeBMDWheel rightWheel;
  int leftSpeed = 0, rightSpeed = 0;
  int outputPin = 7;
  int inputPin = 4;
  int val = HIGH;
void setup()
{
  pinMode(outputPin,OUTPUT);
  pinMode(inputPin,INPUT);
  leftWheel.setupPins(8,11,9);
  rightWheel.setupPins(12,13,10);
  leftWheel.setDirectionMode(1);
  rightWheel.setDirectionMode(0);
}
  void loop()
{
  val = digitalRead(inputPin);
  digitalWrite(outputPin,val);

if (val =HIGH)
{
  forward();
}
else (val = LOW);
bounceL();

}

void forward()
{
   leftWheel.setMotorPower(150);
   rightWheel.setMotorPower(150);
   delay(5000);
   leftWheel.setMotorPower(0);
   rightWheel.setMotorPower(0);
}

void bounceL()
{
  leftWheel.setMotorPower(-50);
  rightWheel.setMotorPower(-50);
  delay(2500);
  leftWheel.setMotorPower(-50);
  rightWheel.setMotorPower(50);
  delay(2500);
  leftWheel.setMotorPower(0);
  rightWheel.setMotorPower(0);
}

If you have got this far and understand what I am doing, you will also have noticed that there is at least one line of code here that is unnecessary. It's a hang over from some earlier testing and will be removed before I produce the next version.

The lovechild of an alliance between Arduino and Pi?

That got your attention didn't it?

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 Arduino IDE 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.

Function this!

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.

Presenting, TagBot 3

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.

All good stuff

as a good friend used to say.

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.

Breaking News.............................

Not really, it just looks good.

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.

And orft we jolly well.................

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.

Oh Calamity!

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!