All Questions
67
questions
0
votes
2
answers
79
views
Can I treat the USB controller in the ATMEGA8U2 as seperate from the rest of the microcontroller?
I'm working on a project that runs on a battery, but can be connected to a computer for a serial connection/charging. In the documentation it lists an example of a bus powered USB controller with ...
0
votes
0
answers
33
views
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, ...
0
votes
3
answers
358
views
What is the GPIO voltage level of a ATMega32U4 when powered from USB?
I found a nice little device that utilizes the ATMega32U4.
Although I tried to find this particular information in the datasheet, I couldn't (more than 400 pages):
When this tiny chip is powered ...
- 969
0
votes
1
answer
51
views
Powering AT90USB162 microcontroller from USB
I have a new AT90USB162 (docs). I would like to use my USB 2.0 socket and USB cable as a power supply for the microcontroller. I have two questions:
How to adjust the current flow? In the ...
0
votes
1
answer
2k
views
How to connect USB to an ATmega328p?
I'm making a board that requires an ATmega328P to respond to commands from a computer. It needs to be connected with USB. I am new to this and trying to figure out how to best do this. I know I'll ...
- 41
1
vote
0
answers
76
views
AVR MCUs parametric search shows number of USB modules but no USB interface
I am looking for AVR MCUs that have USB 2.0 (or greater) capabilities. Using their website for Parametric search, I see that some MCUs have USB modules, but they are not listed as MCUs that have a USB ...
- 3,404
2
votes
2
answers
364
views
ATmega32U4 without USB: how to handle usuned pins
On the ATmega32U4 MCU there are several pins related to USB:
VBUS
D+
D-
UCAP
UGND
UVCC
In the datasheet and in almost all reference schematics I find on the Internet, it's explained how to connect ...
- 1,235
0
votes
1
answer
121
views
Read MicroSD card with USB reader while it is connected to (powered-off) microcontroller
I have created a small breakout board, where a microSD card is inserted and I can access its signals.
Now, when the necessary SD signals are connected to an AVR microcontroller via SPI, they ...
- 391
0
votes
1
answer
168
views
Unable to correctly send keypresses using the LUFA library
I'm making a board with an atmega32u4 on it for the controller for a keyboard, and am having issues with telling the host computer that a key is pressed. I've modified the Keyboard demo supplied with ...
- 734
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 ...
- 1
0
votes
1
answer
384
views
USB device detection problem on a Raspberry Pi
I have a device constructed from a Raspberry Pi 3 B and an AVR based USB device. The interconnection of these components is depicted in this picture.
When RPI is on, data lines of keyboard will be ...
- 101
1
vote
0
answers
2k
views
How to uplad program into Arduino Nano Clone with CH340?
I've started to build a Arduino Nano with CH340g using this schematic:
Which use the CH340 chip :
With one difference, I've use SPI pin to program the MCU.
I've uploaded OptiBoot to Atmega328 and ...
- 119
-1
votes
1
answer
216
views
Why isn't software USB/TTL on ATmega328p working?
I've tried to implement an AVR-CDC project. I found this website which is recommended by V-USB (I know it is pretty old project.)
I drew this schematic:
I've built a PCB basef on it and then I've ...
- 119
0
votes
1
answer
621
views
How to make an Arduino (ATMEGA16U4) like, software USB to serial on Atmega8u?
I've start to build a project base on Atmega328 and I need to connect to it(via USB for availability of the USB port) for debugging (I prefer to debug it with serial communication), and I don't want ...
- 119
1
vote
1
answer
84
views
ATtiny USB data interrupt
I'm trying to use an ATtiny88 to detect data on a USB line. I have an USB data connection going to a hub and a secondary system and I want to use the ATtiny to detect if any peripheral hardware has ...
- 69