In work and life, many problems may arise that can momentarily trap you, but there is always a solution. Always jot down the problems you encounter and summarize them; this helps with accumulation and also prevents repeating the same mistakes.
1. The PIC12F629 has only one interrupt entry, so avoid conflicts caused by multiple interrupts.
2. Pin level changes trigger interrupts, and external INT interrupts will not enter the interrupt program execution when the global interrupt enable (GIE) is cleared.
3. To wake up the microcontroller from sleep, it often uses pin level change interrupts or external INT interrupts. If the former is used, pressing the button will wake it up, and releasing the button will also wake it up. If there are other interrupts at this time, such as initializing a timer with GIE set, conflicts between the two interrupts can occur.
4. If the I/O ports of the PIC microcontroller are used as input pins, the comparator must be turned off during initialization; otherwise, it will not respond.
5. A watchdog overflow can cause the microcontroller to wake up from sleep.
6. When using the PT2262 with the microcontroller as a transmitter, if using a battery, it is essential to minimize power consumption. Normally, the microcontroller sleeps, and the PT2262 is powered off. A transistor can control the power supply of the PT2262, powering it only once during transmission.
7. In the 315MHZ amplitude modulation circuit, the selected frequency inductor can be a molded inductor or one that you wind yourself; however, it is best to use a one-ended toroidal PCB copper wire.
8. The length calculation formula for the 315Mhz transceiver antenna is: L=1/4 wavelength; where wavelength=3.0*10^8/315Mhz. The optimal matching antenna is about 25cm; a telescopic antenna can be used, and a long thick wire on the PCB can also work.
9. The receiver uses a super-regenerative receiving circuit; the widely circulated schematic on the internet can be used after being copied. I have also borrowed it once, and I hope it works. Understanding it is not easy.
10. If a P-channel MOSFET can be avoided, it should be, as it is expensive and has a large on-resistance, resulting in high power consumption. When the microcontroller outputs 0, it easily turns on, but when it outputs 1, if the source of the MOSFET is connected to a voltage higher than the microcontroller’s high level, it cannot be turned off and requires a three-terminal device for shutdown.
11. Setting the via to an outer diameter of 0.4mm and a hole diameter of 0.2mm is theoretically possible, but someone told me that PCB manufacturers might not be able to do it, though I think it shouldn’t be a big problem.
12. Be patient during debugging. Stay calm and reflect often; no one succeeds at once; everyone fails many times before succeeding. When confused, express the problem; an observer can provide insights.
