Questions tagged [avr]
AVR is a 8- and 32-bit microcontroller core developed by Atmel. AVR was chosen as microcontroller for the first generations of the popular Arduino SBCs.
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Dual Slope integrator voltmeter improvement in Design
So, I'm attempting to design a dual-slope integrator voltmeter. I have the following block diagram so far.
Now an AVR microcontroller will have an ADC pin in the range of 0-5 Volts . So negative ...
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Regulating multiple +5V sources to one output to increase current, but avoid interference/noise
I'm designing a circuit with 4 USB 2.0 upstream ports that each connect to their own AVR (ATMEGA32U4), 1 master and 3 slave connected via I2C, master then communicates with a USB controller via SPI, ...
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AVR code - where is Z register pointing to?
I am disassembling AVR code from a bit of hardware. The processor is an Atmel-8.
On restart, after setting the stack pointer, the program calls a subroutine that starts with:
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3V oscillator to 5V µC with an 74HCT inverter (12.8 MHz) - bad idea?
I'd like to use an AVR (ATmega328P-AU to be precise) in combination with a fairly accurate oscillator for timing purposes. I stumbled upon the fact that oscillators which have greater accuracy mostly ...
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avr debugWIRE On chip debug system
I am new into avr and am working on atmega328p. I am not able to understand the avr debugwire system. What is this and how it works. I am seen the datasheet but am not getting a good clear ...
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Multiplexed keyboard based on MOSFET for AVR gives sometimes wrong reading
I made simple example for multiplexed keyboard 2x2 on AVR. Like schematic below:
And Source code:
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AT90USB1286 bricks after disabling clock divider
I have an AT90USB1286 which is connected to a 16MHz external crystal oscillator. It is my understanding that by default from the factory the CKDIV fuse is enabled which makes the chip run at an ...
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Switching reference voltage with capacitor on AREF
I do two conversions (ratiometric measurement) with AREF = AVCC = VCC = 3 x AAA battery. AVCC is connected to VCC via an LC network as recommended in the data sheet of the ATmega328P. I would like ...
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Why is nothing happening on my CLKOUT pin, despite the RTC working fine? [closed]
I apologize for the (probably) trivial question -- I'm just starting to get back into coding for MCUs after a long hiatus, so please be patient with me.
I'll preface this by acknowledging that there ...
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ATMega32U4 USB design considerations
I'm desigining a board with ATMega32U4 microcontroller.
The board will be minimal, and will feed the microcontroller from USB of an M.2 socket (E type) on a PC mainboard:
Now, checking Leonardo's ...
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How can I do immediate addition in the Atmel AVR instruction set?
I've been doing some AVR assembly programming for a university course, and I recently happened upon a situation where I would have wanted an "add immediate" instruction. However, no such ...
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Schematic design for CJMCU Beetle?
I have this bare ATMEGA32U4 breakout:
There are no components on the backside, and I need to redesign this for my own purposes.
I'm looking for the schematic design of this. Although I can reverse ...
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Cannot stop Microcontroller's Hardware Timer from running
I'm using an Atmel ATMega8 microcontroller to control a stepper motor. (Datasheet).
Timer1 (a 16-bit hardware counter) is used in CTC mode to modulate an IO pin to provide the stepping signal to the ...
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Driving 10ch outputs with 5V AVR
I use a 5V AVR (ATmega1284p) to measure some data. Depending on the data I would like to switch one of 10 outputs.
Each of these outputs should have a LED (as an indicator and for debugging purposes) ...
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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 ...
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