T962A Controller with 5"/7" Touch TFT (*STM32*)

Alright,

Version 1.0.0 is up, posted the source code and compiled binaries. 

Got 5.0" and 7.0" both working, I will update the build docs soon to reflect the two resistor changes needed for the 7.0" backlight voltage..

but for now it's all good, and I will keep testing and running version 1.0.0, and of course keep updating (and making new versions) to make the GUIs better, etc, but for now, this should be a good starting point.

Finally,

Happy 4th!!

Have a good working codebase that I'll upload as a version 1.0.0, probably tomorrow after I get a replacement 7.0" screen, as I sort-of mangled the prior one with all the tweaking and moving around trying to get board layouts right.
(I've managed to destroy 2 or 3 screens total now.. lol)

Took a bit longer than expected, but I needed to clean up so many bugs I encountered..

Just as an FYI, since I haven't given too much details yet, (I plan on writing up a USER GUIDE soon), the way I created this you can have profiles that can be up to 30 MINUTES max in length!  pretty sweet..

And they are 5 second interval points (whereas stock oven code was 10 seconds for each point), could've gone higher resolution, but in this type of environment, oven with heating elements, the heater reaction time is so slow, it's a total waste of time and bandwidth having finer point resolution, as it does nothing...

so 5 seconds seemed way more than enough, even 10 secs is still prob. fine, can always go back to that if it turns out 5 secs is a waste as well.. anyhow...

1) you can 'manually' draw profiles via the touch screen, 1 page at a time (3 total pages), since I can only fit about 12 minutes of profile on a screen at a time

2) you can then 'edit' the entire profile, and change temps, etc, just like old oven software (1 page at a time)

3) running the profiles, which can be up to 30 mins length, and can then view the run data 1 page at a time when it's over

4) all sorts of settings and things can be changed in the settings menu, etc, and there is an 'About' menu that gives you build number, memory usage, etc..
and much more... all settings saved in a 'config.ini' that is on the microSD.. as well as profiles are saved/loaded/deleted from the microSD..

5) Also you can configure you own background 'wallpaper' (800x480) JPG image that is loaded from the SD card... since at the main menu there are buttons on the side for doing things, but majority of the screen is your background wallpaper, to make it look cool!

Finally,

This board revision is perfect, RTC and battery is all working, will verify tomorrow once my ML2032s show up (the recharagable CR2032 variant) that the charging and everything holds.

But board is good, LCD 5.0" & 7.0" both now work, looks awesome.  I am very very impressed with JLCPCB manufacturing, and it only cost me $40 for the board!...and you got 5 of them :)

I'll update the schematics, eagle files, etc tomorrow... and hopefully in the next few days be posting the working code.

Finally got the 7.0" TFT working, wow does it look awesome, but it's big!  There was a discrepancy between the TFT datasheet and STMicro's datasheet, still not sure whom is right.. but whatever... it works..

Since the 7.0" looks so good, and works the same, I decided to see how to best make the board easy to switch between one or the other, so I had to slide the connectors around a tiny bit... plus since I was making a change I added a socket for 'ML2032' (rechargable CR2032 battery), and changed out the RTC clock to a true low-power crystal like the STM32 eval boards use.

This allows the board to have true battery backup for the Running Clock, so the thing can actually have a true time clock/calendar that doesn't lose it's settings :)

Just a nice extra I wanted to make work.

I'm cleaning up some more bugs and edge-cases that I identified, so will put up an initial software version prob. next week now, as I want to test it out some more, and possibly get that board revision back next week to test out..

I should be posting an initial version 1.0 of the code this week, as well as production hex/binaries for easy flashing.  The code is pretty good now, will have plenty to improve/work on as this moves forward, but it's at a nice spot now.

I will work on updating the build instructions this week, to include pics/mods to the oven case, as well as installing the LCD itself.

Also will put up a 'flashing instruction' doc, step by step on how to flash the board with the FTDI cable, using a production .bin/.hex file...

Should have some goodies posted up this week..

The 7.0" screen looks SO good on this oven, only bad part is the one I received may be bad, as I get ZERO picture on it, the lcd backlight works fine.  So I have to see if Newhaven can get me another, or if there is something else I'm missing..

But wow does it make a much better look than the 5.0" as to how it fits...

Finished and published initial version of 2 'building instructions' for the procedure I recommend for assembling the board.  You certainly don't have to follow this approach, but it's how I've been building mine, and is the safest way to prevent you from blowing up the expensive processor.

Also, I made a minor update to the PCB, now labelled version 3.1C (previous version was 3.0C).

It's just a 1-wire addition for adding a second pin to receive the RTC clock signal.  I wanted to have a separate timer fed by the RTC clock so I could have a good 'seconds' counter and not have to keep resetting the real RTC clock.  AS I would like to at some point have a battery-backed-up RTC clock circuit so that the oven can retain a real time clock for however long the standard CR2022 or whatever battery can last!

But currently there is no battery backup, so for now it will still lose real clock settings once you turn off power.

** Note: ** you do NOT have to do this mod if you already built this PCB, and don't feel like doing it.  I will provide a compile switch as well as two production '.hex' files:

1) WITH the second RTC clock enabled (if you did the mod or built the latest 3.1 PCB)

2) WITHOUT the second RTC clock

I should have reflow running soon, I am working on this particular GUI's now and working the the graph display for it all..

Still making good progress on the GUIs, getting much closer now..

I do have plans to write up some documents to post on here, to help with:

1) Building instructions (some general instructions on best approaching to assembly the PCB)

2) Programming the board through the UART with STM USB Flasher & FTDI cable

3) How to add the 7.0" TFT instead of default 5.0" TFT

FYI, it is MUCH MUCH nicer when using the NON-BRACKETED LCD screen, you can just use super-sticky adhesive tape on the back of the screen, to stick it right to the oven front panel.

I updated the pic in the project with how it looks, only a small bit of the lcd ribbon cable sticks out through the slot with it mounted in this fashion.

Now the only bad part is my oven has 4 ugly drilled holes from my mounting experiments, LOL.. oh well, I'll fill them in with some gray caulk to try and make it not so ugly.

i.e. definitely get this version of the TFT, ie without the mounting bracket:

(it's also in the BOM)

https://www.newhavendisplay.com/nhd50800480tfatxlctp-p-6062.html

*** Also ****

It looks like it would be fairly easy to drop in the 7.0" TFT versus the 5.0", same resolution 800x480, but gives you a bit larger display..

I may indeed grab one of these and try it out, would require a simple change out of the two resistors that setup the voltage for the LCD display driver, as the 5.0" requires approx. 19.0VDC for the backlight, whereas the 7.0" only takes 9.6V..

https://www.newhavendisplay.com/nhd70800480efasxnctp-p-9501.html

I'll give it a try after I get an initial version of code working for this project

I finished up the BOM and uploaded it here as well as the github repo.

*FYI*:  For those wanting to build this, I put TWO variants of the 5.0" TFT in the BOM, in my attached pics I used the 5.0"  version that has 'mounting tabs' as you can see in the pic.  I kind of made a mess of my T962A cover as you can see in the pictures, moving the mounting holes around..

I DO think it will look cleaner and simpler if you buy the 5.0" WITHOUT the mounting tabs, ie just buy the $61.50 version, and all you need to do is just dremel the 'slot' you see in my one picture... that's for the ribbon cable assembly to pass through to the board.

This way you can just mount the flat TFT screen to the oven cover with sticky tape or whatever, no need to drill screw holes.

I'm probably going to do that myself, and remove the screen from the mounting bracket and just stick it straight to the oven cover, also it won't be sticking out as much :)

Also,

forgot to mention, you do NOT need to populate the JTAG header NOR do you need to buy a debugger OR install any IDEs if you only want to build the board and run the software.

The STM32 processors are sweet in that you can download code to them with just a simple USB<->RS232 3.3V TTL adapter cable (I posted the link in the project).. ie simple FTDI cable about $15 from amazon..

So once I have a good build going, you can simply download the compiled. hex binary, connect the cable to the RS232 header on the board, flip the jumper, and flash it with the free STM flasher tool, which I will post a link to eventually..

but just an FYI for those not interested in actually playing with the software and doing any coding,, but just want to build and run the board... you don't need any JTAG gear or IDE tools...