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Questions tagged [atmega32u4]

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USB on ATmega32U4 powered at 3.3V

I have an already-designed board that uses an ATmega32U4 (a board of our own design). It is USB-powered at 5V and it has an external 16MHz crystal. Below is a screencapture of the relevant portion of ...
Cal-linux's user avatar
  • 2,153
0 votes
1 answer
48 views

Troubleshooting PCB with ATMEGA32U4

I recently designed my very first PCB around the ATMEGA32U4-MU. Unfortunately the chip isn't recognized when connecting the board to my computer via USB. The LED turns on however, so the power section ...
Andreas Vida's user avatar
9 votes
1 answer
113 views

What does a USB device need to do so that the host device can sleep?

I am using an ATmega32u4 that is connected semi-permanently to a mobile Android device (specifically, a keyboard connected to a phone). While the device is connected and USB is enabled on the ...
Dakkaron's user avatar
  • 879
0 votes
0 answers
46 views

ATMEGA32U4-AU Schematics Sanity Check

I had previously asked a few questions about ATMEGA32U2 and got great feedback. I updated my schematics and went ahead to order, only to realize that JLCPCB is currently out of ATMEGA32U2. I have ...
iMan Biglari's user avatar
1 vote
0 answers
51 views

Open-Source Temperature Logger (HELP)

I am almost finished with the development of an open-source temperature logger (USB + battery powered). I have built the PCB using ATMEL ATMEGA32u4 with feather 32u4 bootloader (3.3V 8MHz). Its an ...
Chase's user avatar
  • 11
0 votes
1 answer
98 views

ATMEGA32U2 Schematics Sanity Check

I am not certain if this is a thing, but I was hoping for some members to sanity check the below schematics I have for an ATMEGA32U2. The external LCDs the ATMEGA32 is communicating with are TTL and ...
iMan Biglari's user avatar
1 vote
1 answer
392 views

4 Layer PCB layout with microcontroller and IMU

I'm trying to design a 4-layer PCB board and would like to check if the following layout will perform well. By well, I mean if it will perform optimally. Factors such as Low EMI and noise coupling etc....
Yeo's user avatar
  • 23
0 votes
2 answers
91 views

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 ...
Daniel's user avatar
  • 969
0 votes
2 answers
466 views

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 ...
Daniel's user avatar
  • 969
1 vote
2 answers
352 views

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's user avatar
  • 105
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85 views

Control Neopixel with SPI on an ATmega32U4

I want to control one Neopixel using an ATmega32U4 (only one, so there is no problem with chain timing propagation). With the bit-banging library it does work great, but I want to use the SPI to free ...
Rastersoft's user avatar
0 votes
2 answers
874 views

PCB design review (ATmega32U4 keyboard PCB)

I've been working on an ATmega32U4-based PCB for a custom keyboard for a while now. I made a few prototypes with similar designs, but they all seemed to have issues with the microcontrollers dying ...
Andrew Chao's user avatar
0 votes
2 answers
375 views

32u4 not recognized by FLIP

I recently built a custom PCB with a ATmega32u4. When I plug it in to the USB port it is recognized by windows in the device manager as "ATn32u4DFU". I however can not open a USB port ...
matthew choe's user avatar
0 votes
0 answers
594 views

ATMega32u4 power consumption with CLKDIV8

I have a little board with an ATMega32u4, that's run straight off USB voltage. There are no peripherals on board that should draw power (no LDOs or anything, LED is off). It has a 16MHz crystal. The ...
Dakkaron's user avatar
  • 879
1 vote
1 answer
1k views

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 ...
degebine's user avatar
  • 113
0 votes
2 answers
344 views

How to test if a ATMega16u2 is working

I have designed a custom ATmega16u2 board, however, I cannot connect to it using USB. All connections seem to be correct, and I have checked that the voltage regulator is working, regulating it to 3....
ElongatedYeet's user avatar
1 vote
1 answer
364 views

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 ...
Dakkaron's user avatar
  • 879
2 votes
1 answer
144 views

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 ...
Seif_1999's user avatar
0 votes
2 answers
428 views

AVR reset pin capacitor causes chip to enter bootloader on powerup

I have a circuit using an ATmega32U4 and am using the Arduino Leonardo/Micro Caterina bootloader (the one that comes with arduinoIDE v1.8.13). The problem I am having is on power-up (via USB ...
Scott's user avatar
  • 191
3 votes
1 answer
2k views

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 ...
Blair Fonville's user avatar
0 votes
1 answer
247 views

ATmega32U4 I/O Pin Alternate Functions

I am using an ATmega32U4 as a master with 2 slave ADCs (AD7739), ADC1 and ADC2. The two ADCs are identical. The SS, SCLK, MOSI, and MISO for ADC1 correspond to ports PORTB0,1,2, and 3 respectively, ...
Zachary's user avatar
2 votes
4 answers
2k views

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 ...
user29946's user avatar
0 votes
3 answers
431 views

Does a USB port provide enough power for my LED project?

I'm not quite sure whether or not my LEDs will draw too much current. I can't put the schematic right now, but basically I'm using just using the power line from the USB 2.0 port on my board, and it ...
Brady Davis's user avatar
1 vote
0 answers
136 views

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 ...
Daniel D.'s user avatar
1 vote
0 answers
82 views

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 ...
Daniel D.'s user avatar
0 votes
0 answers
95 views

How to change LUFA default 8MHz crystal setting?

I have an Atmega32u4 micro controller with minimum hardware design. It has an embedded USB compatibility which can be enable/used with some software like LUFA. Everything works fine (the computer ...
hiwuqas's user avatar
0 votes
0 answers
31 views

32U4 based board sometimes does not run setup

I have a custom PCB using 32U4. Sometimes when I switch the board on, the code of setup() function does not run. But this is quite unfrequent, the board usually works fine. This just happens from time ...
Olivier's user avatar
  • 41
0 votes
0 answers
112 views

Issue with daisy chained arduinos and serial communication

I have a setup with a 32U4 based board and 2 daisy chained 328p based boards. Boards are connected via 4 wires : VCC, GND, TX, RX 32U4 is powered by USB Daisy chain is : ...
Olivier's user avatar
  • 41
2 votes
1 answer
230 views

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 ...
Trey Jenkins's user avatar
1 vote
0 answers
75 views

Bidirectional logic level converter with voltage regulator and 5 volt microcontroller

I have to use an N-channel enhancement mode Mosfet based Bidirectional logic level converter along with a fixed 3.3 voltage regulator along with 5 volt micro controller. I am powering the low voltage ...
tshivam's user avatar
  • 11
0 votes
0 answers
213 views

Atmega16U4 (Hardware USB) does not show up as DFU device on device manager

I am trying to get the Atmega16U4 to show up in windows device manager. Right now, when I connect the atmega16U4 through USB to the computer it does not do anything (does not even play the USB ...
Harid444's user avatar
0 votes
2 answers
175 views

PCB with multiple Arduinos and onboard hub

I'm designing a PCB for an astronomical observatory which needs several Arduino Micro to control different devices. Since the circuit must fit a very small space, I'm putting an onboard USB hub to ...
marcocipriani01's user avatar
1 vote
1 answer
119 views

Cannot connect Arduino Uno REV3 ATmega16u2 serial connection to outside serial connection

I wanted to simply use the ATmega16u2 on my official Arduino Uno with a serial connection. I connected my Serial Board (where I can simply connect any serial connection and read it on my PC via Putty)...
Syrin's user avatar
  • 13
1 vote
0 answers
2k views

Why is my atmega32u4 not showing up as a USB device

I have an atmega32u4 as part of a PCB that I designed. The atmega32u4 comes with a USB bootloader and so I should just be able to plug it into my USB port and have it show up as a device. It doesn't ...
Zyzzyphus's user avatar
0 votes
0 answers
182 views

Can I communicate with an Atmega32U4 through USB during runtime?

I'm designing a PCB circuit to do PID control using sensor data to control a robot. I'm new to using micro-controllers other than Arduino and I'm having some trouble figuring out exactly how ...
Zyzzyphus's user avatar
0 votes
1 answer
551 views

How do I program an ItsyBitsy 32u4?

How do I load code onto a ItsyBitsy 32u4 without using the graphcial Arduino IDE? I've looked for "ItsyBitsy 32u4 programmer" and ItsyBitsy 32u4 bootloader".
everett1992's user avatar
0 votes
1 answer
1k views

Atmega32u4 USB and USART

I have an ATMega32u4. My question is about the bootloader section. How does this device pretend to be a com port while connected to USB? What makes the computer think it is a com port and how can I ...
Anton Stafeyev's user avatar
0 votes
1 answer
314 views

Atmega32u4 constant `1023` reading on ADC Channel

I can't share the schematics as they are not mine, I'm trying to add an analog thumbstick (4 pins, Vcc/GND/x/y) to my atmega32u4 powered keyboard. The thumbstick pins are connected to pins PB4 (ADC11)...
pyrho's user avatar
  • 103
1 vote
2 answers
754 views

Can I use the internal Atmega32u4 clock for USB applications?

I believe I can set a fuse in the atmega32u4 to tell it to use its internal clock rather than an external crystal. Would the internal clock be acceptable for using the microcontroller as a USB HID ...
Jacob Garby's user avatar
0 votes
3 answers
1k views

What fuse to set to enable 16MHz clock on the atmega32u4

It's my first time attempting to program an Atmega32u4, or any microcontroller for that matter, on a custom board I got printed. avrdude has a weird output when I, for example, run this command: <...
Jacob Garby's user avatar
1 vote
1 answer
940 views

Issue with programming Atmega32u4 (lfuse memory not accessible using FLIP)

From my last question, I've managed to connect my Atmega32u4 to my computer. Now, when attempted to initialise the bootloader using avrdude, I get the following error message: ...
Jacob Garby's user avatar
2 votes
2 answers
12k views

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 ...
Jacob Garby's user avatar
0 votes
2 answers
402 views

ATmega stopped working after changing CKDIV8 fuse

I have ATmega32U4. I connected it via SPI programmer and in Atmel Studio I have read their signature properly. It was working. Then I cleared and programmed CKDIV8 fuse. Clock was set to internal RC. ...
Misaz's user avatar
  • 385
0 votes
1 answer
1k views

Help with Atmega32u4 custom PCB

I have attempted to design my own custom Atmega32u4 board, but when I assembled it it didn't show up in windows device manager. I fixed the problem where I forgot to connect VBUS to VCC with a jumper ...
Fabian Cojman's user avatar
3 votes
1 answer
1k views

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 ...
marcu5's user avatar
  • 31
2 votes
1 answer
190 views

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 ...
Tyzoid's user avatar
  • 123
0 votes
1 answer
84 views

Why PINxn with pullup reads zero when nothing is connected to it?

Consider the following C-program: ...
Igor Liferenko's user avatar
0 votes
1 answer
480 views

Will other devices interfere with programming a ATmega32U4 if attached to SPI bus?

I’m designing a custom PCB around an ATMega32U4. The 32u4 will talk to another onboard component via the SPI bus. Since the SPI pins (MISO, MOSI, SCK) are also used for ISP programming could other ...
Jeremy Raymond's user avatar
0 votes
1 answer
2k views

Is my PCB layout ok? (ATMEGA32U4, WizNet W5500, Ethernet)

I want to design a device that listens to certain network communication and calculates a MIDI clock signal out of this information. The MIDI output is via classical MIDI port or via USB MIDI. I am ...
Spatz's user avatar
  • 169
0 votes
1 answer
416 views

i2c interference on coiled wire

Hello good day I been trying to build split keyboard using 2 pro micro. I'd been following let's split keyboard using qmk firmware. And the connection diagram of the i2c is this When doing it on ...
zer09's user avatar
  • 101