All Questions
Tagged with avr atmega328p
65
questions
0
votes
1
answer
36
views
Why did fuse bits successfully reset using ICSP and USBASP programmer?
I read a lot about fuse bits in AVR microcontrollers and everyone says that fuse bits can be reset by using high-voltage programmer only, they can't be reset via UART<->ICSP.
So, I've received ...
0
votes
2
answers
143
views
AVR ATmega328P if statement wrongly executed after reset
I have simplified the listing to bare minimum where I can still observe this behaviour.
When this program is running, it works as expected. Button press causes LED to show up.
The problem exist on ...
- 940
1
vote
3
answers
300
views
ATMEGA328 out of memory, but avr-size reports I still have a lot of space
I have a program written in C. I have 390 byte array defined and a long string value consisting of around 475 bytes. Now I hit a problem if I add more characters to the string value, around 30 bytes, ...
- 481
1
vote
1
answer
94
views
ATMega328p wakes immediately after sleep
I'm having issues with my current AVR-C project that runs on an ATMega328p. After issuing the sleep command the chip wakes up again immediately.
I want to wakeup with an external interrupt, but while ...
0
votes
1
answer
52
views
How to make a circuit which can give divided voltage to ADC and can send a trigger pulse to INT0 when I press a button?
I connected 4 buttons to the ADC module of AVR-ATMega328p with different resistor values,
To know which button is pressed this ...
- 45
1
vote
1
answer
387
views
How do I measure distance of Ultrasonic Sensor HC-SR04 using the ATmega328P Timer Input Capture?
I am using an ATmega328P MCU with an 16 MHz external oscillator. I need to measure distance of Ultrasonic Sensor HC-SR04 using the ATmega328P Timer 1 Input Capture interrupt. I have to measure the ...
- 25
0
votes
1
answer
83
views
Software serial not sending the first byte correctly
I implemented the following program to send data to a serial monitor.When I run it, I expect to see abcd but I always see ⸮bcd:
<...
- 475
0
votes
1
answer
142
views
ESP8266 responds with gibberish and 'ready' to AT commands from C program
I have gotten the ESP8266 working by sending commands manually from the TTY. Now, I'm trying to connect to wifi using the following C program:
...
- 475
6
votes
1
answer
460
views
How does USART know which port to use for IO?
I'm trying to learn to use USART on an ATmega328P. I'm using this datasheet.
I'm using the following code to echo characters I type on my terminal:
...
- 475
0
votes
0
answers
92
views
What are the control lines in the ATmega328P for?
I'm trying to understand the block diagram for AVR architecture in the datasheet for ATmega328P on page 9. In it, I see that instruction decoder is connected to control lines. What are they in terms ...
- 475
1
vote
1
answer
476
views
Understanding assembly code for LED blink with ATmega328P
I wrote the following program to turn an LED on and off at 1-second intervals:
...
- 475
3
votes
2
answers
2k
views
ATMEGA328P reset circuit, not pulling down fully
Attached is the schematic of a reset circuit. When I press the reset button, the voltage on the reset pin is 2.5 V. Rmoving R13 naturally solves the issue, but I'm unclear as to why the ...
- 95
1
vote
0
answers
248
views
Best frequency for ATmega328P using internal oscillator?
I wonder what frequency I should set for the internal oscillator of my ATmega328P.
I'll only be reading and outing digital signals, 1s and 0s. I'd like for the processing to be as fast as it can get, ...
1
vote
2
answers
1k
views
Reading LM35 temperature sensor with atmega328p [closed]
I want to read the temperature using LM35 and atmega328p so when the temperature equals or less than 30 a red LED (PINB0) will be turned ON, otherwise a green LED (PINB1) will be ON but I did not get ...
2
votes
1
answer
76
views
Strange behavior when splitting an AVR program across functions
I'm trying to run a very basic "blinker" program on an Atmega328P. Here it is in its entirety:
...
- 147