DT Ints not working on 16F18426

[Ioannis]

Tottaly agree with that.

I got in a rabbit hole trying to make a keyboard matrix work in an ISR along with debounce etc. Just a waste of time...

A tight loop is just fine. And as tumbleweed noted, use Interrupt just to note MCU that a key was pressed, maybe wake it up from sleep. Then a loop will do the rest.

Even if other interrupts are needed when keyborad is serviced, ISR will do that just fine.

Ioannis

[mpgmike]

Darrel Taylor's Instant Interrupts (DT_INTs) changed things for the PBP world. PBP Interrupts are Polled, not actually using the built-in Interrupt hardware. Using ASM somewhat defeated the reason to buy PBP in the first place. Earlier PICs stayed with standardized naming conventions, Bank selection, and Bank location of SFRs. Newer PICs gave new names to familiar peripherals; like changing TMR2 to T2TMR for example. The newer PICxxQyy PICs even changed the default Bank from BANK0 to BANK4. No wonder DT_INTs no longer worked.

A small group of us dove into the ASM behind the scenes for the DT_INTs and uncovered the working mechanisms. By changing naming, BANK locations of SFRs, and a few other things, we were able to get the incredible DT_INTs working on newer offerings. The good news is that a collaborative effort spells out what these changes entail, and how you can do it too. This body of work is available in The Book of DT's Interrupts.

[Ioannis]

It is not very easy or straightforward to make a new or modify the existing file and cover a new chip.

At least for me. Just did a mess and gave up. I really do not follow what the DT-INTS does, so it is difficult to succesfully make a new chip addition. Wish there were step by step instructions for this.

Ioannis

[mpgmike]

Did you look at the DT Book of Interrupts linked 2 posts ago? In fact, the main page lists you as one of the contributors. The part I contributed focused on what to change to add new chips. Take a look (or a refresher).

[Ioannis]

I guess you mean this article:

https://dt.picbasic.co.uk/INT16/Customisation

I am pretty sure that did something stupid and the modified interrupt did not work as expected. Ended to make a poll of the interrupt bit and finished my project.

OK, will give it a try again. With a bottle of coffee this time!

Ioannis

P.S. The 18 series requires modifications in 2 places. Why is that? Because of the priorities?

[tumbleweed]

The 18 series requires modifications in 2 places. Why is that? Because of the priorities?

The first one creates a '#define' used by the INT_LIST, INT_ENABLE and other macros that specifies the PIR reg and bit

  #define INT1_INT  INTCON3,INT1IF  ;-- INT1 External

The second one adds all the details (PIR intr reg/bit, PIE enable reg/bit, and IPR priority reg/bit)

  ifdef INT1IF
      INT_Source  INTCON3,INT1IF, INTCON3,INT1IE, INTCON3,INT1IP
  endif

If you're lucky, that's all that's required. However, some of the newer devices like the 18FxxK42 and 18FxxQ43 required some serious modifications to the asm code to make DT_INTS compatible with the register layout and new instructions like MOVFFL, so the 'customization guide' isn't much help with them.

[Ioannis]

Well, these are the chips I want to have DT_INTS work with...! Among a few others.

Ioannis