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.

PIC 16f877A interrupt – I have been working on a project of Over current relay using PIC 16f877A controller in which I have used interrupt signal to generate an exact time delay (trip signal). For which I have used timer 1 configuration.
It is working all fine when I run its simulation on Proteus, it gives accurate result there. But on hardware sometime it does not gives an interrupt signal; sometimes it gives very accurate time. It malfunctions as well. What could be the reason of this malfunctioning? Why it does not give an interrupt signal? Read more

High frequency using 8051 – I need to generate high-frequency output maxing 60 kHz using an 8051 microcontroller.
Software is not a problem. I would be using a timer to generate high frequency.  Read more

Problem with submersible water pump – I am working on a project with an automatic plant watering system using 8051 microcontrollers. When the moisture in the soil is high, the soil moisture sensor senses it and displays the status at the LCD. But when the moisture is low, the soil moisture sensor detects the status but the motor (which should now be turned on) remains off or either turns on for a second and the relay module that has been connected to the pup motor produces ticking sounds. Read more

Using 0-10V analog sensor output with Raspberry Pi – I am a newbie to Raspberry coding and ckt design. I have 4 analog sensors which give 0-10v DC output and 4-20mA current. I am looking for ckt that can read these range of current and voltage parameter with 12-bit/16-bit resolution. Read more

Invasive blood pressure monitoring – I have attached the datasheets of the BP Transducer (BP Sensor), BP AMP and BP STIMULATOR used in the lab.
The excitation voltage used for the sensor is 5V DC.

Operating range: –50 to +300 mmHg
Excitation voltage: 2 to 10 V DC
Sensitivity (full range): 5 µV/V/mmHg

5uV * 5 = 25uV for 5V and it is equal to 1 mmHg?

If yes, then the range is -50 to 300 mmHg = 350. So, 25uV * 350 = 8750 uV = 8.75mV? Read more

How to make DP flash every sec in 2-digit 7-segments –  I want to make that two DPs flash together at every second without cutting (disconnecting) the tack from common which is already connected with a CA point in a fabricated PCB? Read more

Hardware issues in simple interrupt code PIC16f887 – I want to write a program on IR sensor using NEC protocol. For that, I just started to understand the basic codes of an interrupt. I wrote a coding and executed in Proteus, too. But when I try to implement in hardware mode the interrupt part is not working. Read more

Best solution to use DOT POINT – I want to make a RTC clock with 4-digit 7seg disp which will display ” HH:MM ” in multiplex tech. I have 4 nos digit and each are of CA type. Read more

ULN2803 as input protection – The ULN2803 is commonly used in MCU projects to drive high-voltage or high-current loads. But I have been thinking about using the ULN2803 as a high voltage input protection device to drive MCU digital input pins. Read more

Why ATmega16 is used in Arduino Uno R3 – I want to know why ATmega16 is used in Arduino Uno R3. What is the purpose of placing ATmega16 and ATmega328p on same board? Is ATmega328 is not enough? Read more