Step 1 of 11
Welcome: polling vs interrupts
Goals for this step
When you finish 10 steps you will have a real ISR blinking an LED without checking flags in a loop.
One step = one concrete action you can mark before continuing.
Do not advance if the step checklist is not done.
We will build one file guia-interrupciones.asm that grows each step.
So far in GPIO you read the button with polling (BTFSS PORTB in a loop). Here hardware notifies the PIC when Timer0 overflows: jump to vector 0x0008 (08H) and run the ISR.
Course order: vectors → RAM variables → Timer0 → enable GIE → write ISR → save context → test in Proteus.
Use the guide tracker (right panel): each step has Follow these steps, Your file so far, and Checklist before you continue.
Follow these steps
- Read the tracker goal: LED on RB0 blinks via Timer0 interrupt, not polling.
- Review theory at Interrupts — event → vector → ISR → RETFIE flow.
- Have MPLAB and Proteus ready (you can reuse the LED schematic from the ports guide).
- Click Next — step 1 is creating the project, no code yet.
Checklist before you continue
- I understand polling vs interrupt.
- I know where the guide tracker is on screen.
- I know the high-priority vector is 0x0008 (08H).