Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [atmega32u4]

53 questions
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ATmega32u4 reset circuit and bootloader

I have an ATmega32u4 which I have configured to run its application by default at boot, and to run the bootloader (standard DFU USB bootloader from Microchip) when the reset button is pressed. I intend to use the bootloader for flashing the…
Blair Fonville
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ATMega32u4 VBUS and SMD Schottky Diode

I have spent quite a bit of time trying to work this out, but I just can't. I want to power my ATMEGA32U4 chip via USB, and at the same time send that USB +5V off to the circuit +5V bus per the picture (as I have other +5 devices to power). In…
marcu5
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Re-purpose USB cable to carry I2C

I was wondering if it would be possible to connect an IO extender (MCP23017-E/SP) to an ATMega32u4-AU via an USB cable. I figured that if you connect up the SCL pin to the Data+ of the USB and the SCA pin to the Data- of USB, ground the 4th pin and…
Meowlfhelm
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Strange ATmega32 behavior with assembly code

I posted a kind of similar question recently, but it was not that organized, so here I am trying again :) I wrote this short assembly code to blink an LED at different intervals depending on the state a 2-pin dip switch. The code is working…
Seif_1999
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PCB design review (ATMEGA32U4)

I have been trying to make a watch for the past few months, but all my prototypes have been unsuccessful. So, to try ironing out some problems, I made a practice PCB to try testing my base Atmega32u4 system. It has a CR2032 battery with a boost…
user29946
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Can't program ATmega with ICSP on custom pcb

I'm fairly new to PCB design, and I've been trying to program the microcontrollers on the board I designed with no luck. The board uses an ATmega32u4 and an ATmega328P. I've been trying to program them with a cheap $10 ICSP programmer from Amazon,…
Trey Jenkins
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How can I program an Atmega32u4 over USB with this schematic?

This is my first time trying to program an Atmega32u4. I made a PCB with the following schematic: Now I've soldered all the parts onto the PCB, and I've plugged a micro usb cable from my computer into J1. I assumed that when I pressed down SW1, the…
Jacob Garby
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Atmega32u - Ground in bus powered configuration

The Datasheet provides an example configuration for when the device is powered from the bus, and shows the bus Vss connected to UGND on the avr micro, but shows a connection to earth/ground on the other GND pins. Where is this ground coming…
Tyzoid
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Do I have to provide VCC to every VCC pin on Atmega32u4 MCU?

Atmega32u4 has 7 VCC pins. Can I connect 1 of the 7 VCC pins to the power supply to power the MCU, and use the rest of the VCC pins (6 of them) on the MCU to power other peripherals, such as LEDs?
Adam Lee
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how to program the fuse bits of atmeta32u4 via the usb port?

here I have an avr development board with a core of type Atmega32u4. I can only access to the memory via a usb cable.The default fuse bits seem to enable the JTAG which I want to disable. Unfortunately, the lock bits only allow me to program the…
user125568
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How to make a MAX98357A class-D amplifier work with an Arduino (ATmega32) to play an audio file?

Is it possible to make a MAX98357A class-D amplifier work with a normal Arduino? I've only found solutions based on an ESP32. If not, why not, and is there a solution or an alternative solution?
playmobox
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Connecting USB-C port with ATmega32u4 - Questions

I'm a beginner when it comes to schematics. I'm attempting to create a USB-C + Atmega32u4 schematic. Later I will add cols and rows for keyswitches (usb keyboard). Below is the schematic I came up with so far. It's based on combining these two…
degebine
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ATMega32u4 minimum system clock for USB 2.0

I am trying to cut down the power consumption for an ATMega32u4. The datasheet says, for USB 2.0 it needs an external clock, which it uses to generate a 48 MHz clock by multiplying the external clock up. But it doesn't say anything about what…
Dakkaron
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Feather 32u4 too much current draw

I am trying to build a battery-powered application using the Feather 32u4. I need a timer to trigger every 120 seconds (although Timer1 with it's 8 second limit would suffice for the beginning), thus I tried using IDLE_MODE, which should save some…
Daniel D.
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ATMega32u4 Timer code not working

The following timer code running on a 8Mhz ATMega32u4 should toggle the onboard LED every second, and calling the ISR code manually does so. Yet, the ISR does not seem to get called. Could anyone please help me getting the timer to work? #define…
Daniel D.
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