July Update

Last night I added a MEMORY settings feature,  this allows you to copy /store your favorite programmes in one of three BANK memories (BANK1, BANK2 and BANK3).   For completeness, you can also restore from, and copy between memory banks.

I also added a safety setting so you can set the max kiln temperature before the kiln will automatically shut-off.  this was also in the code but not accessible via the ui.

Latest Firing

(The Parian pieces below were my father-in-laws)






The piece below was mine.

June Update

The other night I fixed a bug in the delete programme part of the code;  this leaves a couple more features to add,  namely "thermocouple offset", in which you will be able to offset the temperature reading of the thermocouple by a user set amount;  this apparently is common among the commercial pottery controllers as the thermocouple is susceptible to aging effects, this in turns adds an error to the real temperature reading, so to ensure a fairly accurate reading this value is offset over time.

The other feature I need to add is the ability to "store" and "recall" your favorite programmes into "memory banks" this will allow better management of the programme sets for the user.

[update]
Last night I added "thermocouple offset" to the settings menu, and it seems to work fine. So,  I'm going to wire-up this new controller for live testing, hopefully, tonight.

Getting Ready For Testing

After a load of little changes and fixes which took me into the early hours this morning and the best part of today, I managed to tidy up and sort a few more bits;  I added 36 default programmes which consist of 36 cone programmes;  these will be the default programmes the controller will ship with straight "out-the-box", so to say.  I've removed all the features that need extra work in order to get the basics up and running in the new chip.

Happy 2018 !

Well, tomorrow is the last day of my Xmas holiday break, and over that time I have really busy;  a few weeks ago I created my first ever clay model, which is a bust of my own interpretation of Hercules, this was then made into a 4 piece plaster mould.  I took out the first stoneware slip cast piece from the mould today (the other 2 fell apart getting them out!) and have been cleaning it up.

In-between doing this, I have been working on the controller firmware;  I did manage to kill another microcontroller by accident, so, I will need to wait until the end of the month before I can replace it, and also buy another controller box to put the new version of the controller in for testing,  I don't want to use controller box I already have as it's already mounted on the wall and hooked up to my kiln using the previous firmware version.

Just a little update on the cheap Ebay thermocouple chips, apparently when I tested then using the thermocouple simulator they appear to drop-off towards the upper end of the temperatures,  I'll try and do a post with some more definitive results.

One thing I did want to look at was changing the board layout on the next version to use the Maxim MAX31855KASA+ which is lot cheaper than the AD595 at measuring temperatures;  if I do this it would make the overall cost of a board a lot cheaper, by comparison, the AD595 is £15, and the Maxim is £5;  the other idea I had was to create an internal real-time clock rather than use the DS1302 chip, as although it's nice to have a real date and time clock;  you only actually need to use a fairly rough clock for timing the firings;  I don't know exactly how accurate an internal microcontroller clock would run but it would interesting to find out as that would reduce the price and complexity even further.

Lots to do!

[update]

Right, I got some replacement parts and bought another box;  I have installed the new test board and hooked up another plugin transformer;  all appears good - I can now use this version for testing the new firmware running on the bigger microcontroller chip.

23rd April Update

Been working a bit on the controller over the last few days;  I managed to get the "create programme" feature added today.   Originally I wanted the user to only use the external PC based software to create the programmes, and then to remotely upload them using Bluetooth, but, having had some time to think about it, I realised that not all users could or would even want to do that,  so,  I have added the option to add new programmes via the keypad.

I think the vent system will need to wait for version 2 as it would need too big a change to the way the programmes are stored.

to be continued... ;-)

Thermocouple Chips

Recently purchased some AD559 CQ thermocouple  chips from Ebay, these were sold at around 4x cheaper than the standard retail price!   I don't honestly know what to make of these yet,  one of the chips looked very suspect - so that will definitely will not be used.  the picture shows the 8 purchased (back row) with the one at the front as the test control chip, which I used to make comparisons.

I think what I will do is put them into the boards and feed in some simulator temperatures and see how they compare to the real deal.