Home brew DRO

I've just read the digital article on the design & build of the DRO using pre-manufactured encoder & Arduino micro controller. When I saw this I quickly became engrossed in the concept & implementation of the system. I've been collecting parts based on an Arduino for a digital RPM & multifuction cutting speed calculator for various machine tools that I have. Fortunately being an Electronics & Electrical Engineer this doesn't phase me too much! I'm very greatfull to see this type of article being offered up although I can understand the more mechanical type frowning under their breath! Like it or not electronics are playing an increasingly larger part in our lives than perhaps some would like. To sum up - thanks for the article & being able to see the installed version. John H.

I too read this article with interest but my problem was a lack of knowledge about how to implement it. While I have a reasonable understanding of basic electronics I fall down when it comes to microprocessor stuff and I am sure I am not alone in this. What is needed is a way of getting over the difficult electronics bit, such as making available pre-programmed pic chips etc. Who would do this is a problem of course, but most problems have a solution.

Doug

I've been playing with an Ardunio recently (which I'm hoping will turn out to be more useful than just doing Suduko) and they are very neat little devices. So I read the article with some interest and whilst I might not want to actually build one of these DRO devices, I would have been very interested in reading the sketch (i.e. looking at the programme) that the authors wrote to implement the device.

I understand that it might have been too large/long to publish but it couldn't it have been available as a download somewhere? Without this key design element - it's a bit like publishing only half the drawings for a purely mechanical device in my view.

Regards,

IanT.

Ian,

There is a link in the web article, telling you where to spend your £5

MichaelG.

Douglas, just to pick up on your comments about "PIC".

The Arduino is interesting because it can be connected directly to a PC/Laptop via a USB connector. You write the 'sketches' on the PC and then simply click a button to download it to the Arduino. Once downloaded the Ardunio can be used standalone (although it will then need a separate power supply) and will run whatever 'sketch' was last downloaded into it.

The Arduino "language" is a stripped down version of 'C' but doesn't seem too hard to learn (well I seem to be making progress). It has also been designed to interact with the real world and there is a quite a good library of functions you can add into your own sketches - so it's a kind of software Lego. These include routines for DC motors, Steppers, A>D, D>A, timers and much more.

So they are a lot more user friendly than a PIC (you don't need a separate chip programmer for instance) and if you are only going to need one or two devices, I think they make good sense. If you want/need to use many intelligent devices (or are mass producing things) then a PIC (and there are many kinds) will probably have the advantage, not least on cost.

My Uno cost about £20 and came with all the USB cables etc. I needed to be up and running straight away. The software is Freeware and can be downloaded from the Arduino site. It's a complete programming/development system which is also widely supported by many individuals, schools and Universities on the web.

Well worth exploring.

Regards,

IanT

Just to be picky and to clarify, PIC microcontrollers are from Microchip and the various flavours of Arduinos are based on the AVRMega series of microcontrollers from Atmel...but all the other sentiments about (relative) ease of programming and not needing a separate programmer are spot on

Edited By Martin Millener on 04/10/2013 16:26:19

Well I saw that Michael (when I first read the article in ME 4461 - which obviously I had just paid for!)

And yes, I guess I could have sent £5 to satisfy my curiosity but I'm afraid that I seem to have a genetic barrier where spending money is concerned. I think it might have been a better model to have offered the download for free and ask for a donation IF the design was actually used. I understand the 'trust' model has worked very well for some individuals on the internet (I've even donated once myself!)

However, my point was that really, as these gizmos begin to creep into more and more of the stuff we might want to build (as I'm sure they will) then the "software" component will become increasingly important and if this bit is not available - then it will cause mounting problems for anyone wanting to build and maintain the project.

Regards,

IanT

If you care to have a look at this site:

http//www.yuriystoys.com

you will see he's implemented an Arduino-based system and bluetooth wireless connection to boot.

It's an interesting read anyway and all his software is open source if you want to follow this route.

John

> The Arduino "language" is a stripped down version of 'C'

I disagree. It is actually a pretty complete C/C++ based on the gcc avr compiler. The Arduino IDE is primitive but with a bit of effort you can use Eclipse IDE which is very good.

Roger Woollett

Edited By Roger Woollett on 04/10/2013 17:08:36

I was cheered to see something with an AVR in it instead of a PIC

(For the confused - Arduinos are essentially breakout boards for AVR microcontrollers, using the AVRs themselves is hardly more complex if you can design your own PCBs.)

I have an AVR based speed readout for my lathe & mill and a (still a little flaky) 3-axis DRO + speed display for my mill, also AVR based.

> Like it or not electronics are playing an increasingly larger part in our lives than perhaps some would like.

I'd be happy to see a 'workshop related electronics' topic on the forum.

Neil

Edited By JasonB on 04/10/2013 20:00:28

Yes, probably a poor choice of words Roger - Arduino "hides" some of the complexity of C/++ might be a better explanation.

And Martin - actually Ardunio is now also available on PIC in the form of the PIC32 (a MIPS architecture) chip that provides considerable horsepower should it be required.

These Arduino compatible boards are available from Diligent see: **LINK**.

As it happens I also have a PIC32 USB Starter Kit - and I understand that you can download (and re-programme) the PIC32 chip with the new Arduino s/w instead of the standard Microchip firmware.

To date however, I've not had the need (or courage) to try it.

Regards,

IanT

Edited By IanT on 04/10/2013 19:06:37

Hi all you electronics boffins, is the Arduino set up similar to the picaxe system which I have come across?

Doug

Hi Douglas,

I've no direct experience of the PICAXE system(s) but as I understand it they are similar in their general philosophy & approach to the Arduino concept;

The PICAXE can be programmed in a form of Basic (or a flowcharting system I believe) and boards built using them are directly connected (by a USB download cable) to a PC. So in these two respects (a high level programming environment and the direct USB tether) they are similar to the Arduino..

Beyond that I cannot make any knowledgeable comparisons in terms of CPU performance, memory size, I/O connectivity, cost, ease of use or the size of their user community - or any of the many other factors that might influence a choice of one system or the other.

In my case, I found some Arduino literature that aroused my particular interest and I decided to buy one.(I was already working with the PIC32) to explore the concept further. I do kind of suspect that once you have invested a bit of time in a particular system that you will tend to stick with it (unless there is a very good reason to change).

The 'familiar' is always a powerful swing factor in these things I think. So if you've already worked with PICAXE then that may be the best/preferred system for you, especially if you are more at home with Basic than C/++. (i.e. whatever tool will do the job for you)

Regards,

IanT.

I have a Nano to run a rotary table.

This is programmed from a laptop and then the laptop is used to run the rotary table, bit of a cheap mans division master and other than soldering a few wires on it's a simple build.

As computing power goes up and price comes down newer systems appear and the older ones fade away. The Arduino is newer so more powerfull than a Picaxe. Now there is the raspberry Pi with more power still but each device has other factors, like interface considerations that suit certain applicatons.

They all make use of a PC to provide a more user friendly programming interface but also each uses a different high level language as a basis though the Pi has become so powerful it can support many languages.

Picaxe - Basic
Kronos Dios - picaxe on steroids
Arduino - C
Pi - Python, Perl, Basic.

Well rotary division was one of the possible applications I was thinking of when I purchased the Arduino John.

One question that immediately occurred to me - is how (with what) have you used to create the PC display? I guess it could be 'Processing' - but would certainly be interested to know.

It would also make a great article in ME/MEW too (assuming they made the code available of course!)

Regards,

IanT

At the risk of alienating Neil, and other Arduino enthusiasts ...

Anyone interested in PICAXE would do well to start here:

The site is run by Revolution Education, who supply to Schools etc.

... Loads of datasheets etc. downloadable for free.

MichaelG.

John,

A question if I may: how is the Nano connected, direct to the stepper?

Regards

Paul

Just a quick reply, gotta shoot up to Machine Mart to get some castors, the wheel has fell off the pram.

The project is just a small part of a larger project that controlled a very expensive camera system and was paid for by a customer.

I got the right to distribute the simple rotary axis part. I post later tonight in depth but I can share all the files.

Probably put a new post up later.

Paul,

The Nano or Uno [ both do the same job ] has a USB cable in one end which feeds 5v and signal to the Nano

Other end has 3 wires coming out step, direction and ground to go to a stepper driver.

As I say I'll post more when I'm welded the the armchair tonight.

> At the risk of alienating Neil, and other Arduino enthusiasts

I've never even seen an Arduino in the flesh!

I programme AVRs directly in machine code, or very rarely badly written WinAVR C (GCC in an AVR wrapper).

Neil

P.S. AVRs can run BASIC: