4 Channel Thermostat using PID loops

[zachschi]

Great post! It must be cool to have a history showing your project going from start to finish. Just curious, did you end up using the Triacs and Optoisolators for cost, size or both? I have a HV control project and I am considering the difference between the two. Thanks.

[Scampy]

Hi,

Yes I opted for the isolators and triacs for both cost and size.

[shahidali55]

Has the incPID_mc.pbp file been modified?
I can see several commented lines.
Has Henrik posted this file somewhere on the forum?

[Scampy]

As far as I'm aware there was no modifications since the original one posted at the start of the thread. Here's the version I have used in all subsequent builds (change the TXT ext to pbp)

[Scampy]

Thought I should update this thread with some more images of the finished MKII prototype which has been running now for just over a year now without any issues.



From the back, and



From the front.

The RS232 connector on the board is obsolete, and is connected to a panel mounted socket on the rear. I was thinking of adding one of those new 232 > USB TTL cables to make connectivity easier, but to be honest I've only ever needed to adjust the time from GMT to BST and back, which was easy from the unit rather than from the PC, so haven't bothered.

[Mike, K8LH]

To many people like me, the result is almost a work of art (grin). I'd love to see some detail on how you mounted the LCD to the front panel...

Happy Holidays.

Cheerful regards, Mike

[Scampy]

Over the years I've received several requests regarding using this code for a commercial product. Whilst I had lots of request there were two deciding factors why it was not pursued. The first was the the fact that others had contributed to the development of the code, namely Henrik and Darrel, and, at the time of development it was for my own private use with no financial gain. It may well be that they would have no issue if the unit was made and sold as a hobby rather than business, but I respect that without formal signed agreements it would be the wrong thing to do. The post here details the development and the code was (is) available as is for others to learn and develop their own PBP projects. If parts of the code are used, then please respect the condition in the header and include all contributors in your code.

The second reason is that any item sold in the EU needs to me certain standards, especially electronics that switch mains potential. The risk in supplying a unit which is not CE marked to someone could result in the supplier / developer being sued or facing a custodial sentence should it be proved that the device was the cause of any loss to person or property. To get the device through the testing, documentation and due-diligence procedure would of cost near £10K, which even if I had the approval from the other parties involved in the code development, was ruled out as I didn't have that sort of money, and given the specialty of the project, there simply isn't enough of a market to recover that sort of cost, let alone make a small profit.

I have also been approached for the development files and schematics etc. These are now archived, and other than what's featured here, will not be posting up any further files, or updates that I have made.

In closing, I would like to re-iterate my thanks to Darrel and Henrik for their help in developing the code for this project, which insistently has been running now for over three years, 27/7, 365 days a year with not so much as a hick up. I've not even had to replace the battery in the RTC !

Malcolm