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Forum Index : Microcontroller and PC projects : How do I disable interrupts ?
| Author | Message | ||||
| 58kk90 Regular Member  Joined: 14/06/2023 Location: United KingdomPosts: 77 |
Guys, I am completely baffled here, I have two pins on the Pico connected to two sensors, the pins are defined like this SetPin GP10,INTH,HallEffectInterrupt1,PULLUP SetPin GP11,INTH,HallEffectInterrupt2,PULLUP In the Picomite user manual under the interrupts section, it states "If you must call a subroutine that is also used by an interrupt you must disable the interrupt first (you can reinstate it after you have finished with the subroutine)" So my question is how exactly do I disable the interrupt? What I want is when the HallEffectInterrupt1 has fired, and i'm dealing with it, setting the flag, doing a bit of code etc, I want to disable the HallEffectInterrupt2 and stop that firing until I have finished dealing with HallEffectInterrupt1. I have searched the forum, and the manual but cannot find any mention of how to disable and re-enable the interrupt. Tony |
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| terekgabor Regular Member Joined: 02/01/2026 Location: HungaryPosts: 78 |
Hello! Do you mean this: These interrupts can be disabled by setting ‘period’ to zero (i.e. SETTICK 0, 0, 3 will disable tick timer number 3). G@bor |
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| PhenixRising Guru  Joined: 07/11/2023 Location: United KingdomPosts: 1913 |
If you have a target sub (mysub in this case) set-up to be triggered by an interrupt SETPIN pin, INTH, mysub do 'main code loop pause 10 loop sub mysub 'this is called when the pin goes high . . . 'do stuff . . . end sub But then you want to directly call the same sub: SETPIN pin, INTH, mysub do 'main code loop pause 10 SETPIN pin, OFF, mysub 'switch off the interrupt mysub 'call the sub SETPIN pin, INTH, mysub 'reinstate the interrupt loop sub mysub 'this is called when the pin goes high or directly . . . 'do stuff . . . end sub |
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| 58kk90 Regular Member Joined: 14/06/2023 Location: United KingdomPosts: 77 |
@terekgabor not quite as it's not a timer interrupt I am dealing with but a hardware interrupt, but thank you. @PhenixRising thank you that is exactly what I want, I wasn't aware that you can change the pin function 'on the fly' so to speak I assumed they had to be done at the start of your code and once defined they were fixed, I was kind of looking for a disable interrupt HallEffectInterrupt2 type of command I guess that was why I couldn't find anything in the manual. Tony. |
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| ville56 Guru Joined: 08/06/2022 Location: AustriaPosts: 493 |
58kk90, you stated: As you are with both interrupts at the same interrupt level (I/O pin interrupt) you will not be interrupted as long as you do not RETURN from the interrupt SUB-routine. So, everything you need to do on interrupt-level, just do it and then return, keeping it as short as possible. In the manual on page 54/55 you will find the interrupt levels (priorities). Inyour case all interrupts except tick and pin I/O can take effect. For me there is basically no difference between staying in the interrupt handler or disabling interrupts for your example, at least from your description. Gerald Edited 2026-05-21 03:33 by ville56 73 de OE1HGA, Gerald |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 8842 |
AFAIK there is only one hardware interrupt accessible to the user and that is triggered by the high speed counter. Under MMBasic all user interrupts are "soft". You define the trigger and a SUB that will run when that event is triggered. There is no "return from interrupt" as such as the next program command isn't executed until the END SUB in the interrupt routine has been executed. Interrupts are handled in a strictly defined priority after each MMBasic command. In this case, define a GPIO pin, connected to the sensor, as the interrupt trigger and use that to trigger an interrupt SUB. That SUB should only set a global flag then END SUB. Now, within the program loop, simply test that flag to see if the sensor has been triggered. If it has then handle it and reset the flag. If you wish the main loop can call another SUB to do the work, it can do this at any time without involving the interrupt SUB as if the interrupt is triggered it will merely set the flag which will be tested in the normal way later. . Edited 2026-05-21 17:16 by Mixtel90 Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 3222 |
Micks method is best if you can afford the time to get back from the ISR and for the main loop to get around to reading the flag. If that takes too long the processing needs to be done in the ISR. So if that Sub is also called from the main loop then, as previously noted, SetPin GPxx, Off as the first line of the ISR and restoring it as the last line is needed. |
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Martin H. Guru Joined: 04/06/2022 Location: GermanyPosts: 1454 |
Disabling (masking) further interrupts when an interrupt service routine (ISR) begins prevents the routine itself from being interrupted by another interrupt. This primarily serves to enhance stability, protect critical sections of the programme and prevent uncontrolled memory overflows. You must therefore ensure that the interrupt routine is not interrupted and re-called mid-execution, as this could lead to unpredictable results. So put that at the start of your subroutine, and at the end, set the interrupt back to its original value. Edited 2026-05-21 18:33 by Martin H. 'no comment |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 11356 |
Nope: The counter/frequency pins are H/W interrupts. The high speed counter isn't. The pin is directly clocking a timer register |
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