Peer-to-peer, engineer-to-engineer questions and answers from the EDABoard.com engineering community around microcontrollers. Click the “Read more” link and follow the entire conversation and maybe add your two cents by logging in to EDAboard.com.

Why more codes do not work with PIC microcontroller – I code for reading EEPROM and edit those EEPROM data and work with those data. Normally I am coding something and upload to PIC and check that code. When I connected LCD with PIC it also shows all pixels ON. When I remove codes in somewhere then again working. When codes are high PIC not working. When codes are less then PIC working. But when I compiled it shows PIC have free ROM and RAM spaces. I am using 4Mhz crystal oscillator and PIC18F4550 microcontroller. I am using MikroC for coding. Why did this happen in hardware? Read more

How can I multiplex the alphabets on 3 digits 7 segments – Using MikroC Pro for PIC16f73, I can multiplex numbers [0-9] on 3 digits 7 segments, but can’t multiplex any alphabet or any custom segments. I want to multiplex “H” and “L” in port B. Read more

Is it possible to measure the AVref reference voltage through software in STM32 – I need to measure the 3.3V input given to my ADC input pin. but the reference to AVref is varying from 3.28 to 3.33 because of this my error also increasing, and if I am calibrating at the time the voltage is 3.28 but after some time its varying to 3.31… so is it any possibility for measuring what the voltage is given to my ADC reference. Read more.

8052-at89s52, HC SR-04 ultrasonic sensor – On 15 CM ,error is 0.5 cm
on 30 cm ,error becomes 1 cm (short). Is there any way to compensate this error by any means like any hardware connection? Or we have only way left with the option of compensating by programming logic? Read more

Can we use TRIAC to turn ON/OFF AC devices? – I am designing a TRIAC based switchboard (remote controlled). I have seen triac based switchboard which turns ON/OFF lights and fans but can I use say 25A rated triac to turn ON/OFF home appliances like refrigerators, washing machines, dishwashers, etc,..? There will be no Phase angle control that is AC voltage will not be chopped but just turn ON/OFF appliances. Read more

Driving 7 segmnet display – For displaying the values I tried to use 7 SEGMENT display instead of LCD. When tried to display the value, the first 3 digits are not showing properly and it is blinking. Read more 

How to program or read STC microcontroller? – I am new to the STC micro and trying to read an STC15W404 microcontroller Can anyone guide me the correct software and way to do this? As per information found on the internet, it is communicating with TX-RX pins but I am not sure whether it will work with a USB uART module. I have downloaded the STC-ISP software and connected the USB-uart module to the said pins but the chip is not responding in any way. Am I missing something? Read more

What is the purpose of reed switches in the pressure switch? – I am reverse engineering this pressure switch. It has two reed switches. I want to know how the reed switches operate. I know reed switches are operated with magnets housed in mechanical assembly. I want to know which reed switch sends what signal to the microcontroller. U have to design exact product but a pressure switch has not been provided to me for reverse engineering. Read more

How to define the line Rb0 to Rb6 = hex (x%10); // no Rb7 pin – Using MikroC Pro to multiplexing 7 segment the written program is
PORTB = Hex (x%10);
there PORTB means RB0 to RB7 total 8 pins are included, but I want to use only 7 pins for 7 segments RB0 to RB6, and the pin RB7 as other O/P.
As like Rb0 to Rb6 = hex (x%10) and Rb7_bit = 0 or 1 or something else. Read more

What is the best bus choice for inter-PCB communication? – I have been asked to design modular I/O boards
for a PLC like device distributed to many small PCBs. The I/O modules will be unintelligent 4/4 digital I/O , 4/4 analog I/O inteligent I/Os like encoder input and step puls/dir output. The max digital I/O number will be less than 32 (4 digital I/O boards). The MCU will be ESP32. Which bus system willl be best between MCU and I/Os for this application? Read more