I have been working on getting an Atmega32u4 connected to USB. I lifted the connections from the Arduino Micro schematic for the preliminary schematic shown here. When I connect the chip to USB, the system (Ubuntu 18.04) does not appear to recognize it.
I was able to burn the Caterina-Micro bootloader via my Pololu USB AVR Programmer as well as through ArduinoISP to confirm that everything was uploaded correctly. The following is the output of avrdude using the pololu programmer:
$ avrdude -p m32u4 -P /dev/ttyACM0 -c avrispv2 -U flash:w:Caterina-Micro.hex
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e9587 (probably m32u4) avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed To disable this feature, specify the -D option. avrdude: erasing chip avrdude: reading input file "Caterina-Micro.hex" avrdude: input file Caterina-Micro.hex auto detected as Intel Hex avrdude: writing flash (32730 bytes):
Writing | ################################################## | 100% 8.21s
avrdude: 32730 bytes of flash written avrdude: verifying flash memory against Caterina-Micro.hex: avrdude: load data flash data from input file Caterina-Micro.hex: avrdude: input file Caterina-Micro.hex auto detected as Intel Hex avrdude: input file Caterina-Micro.hex contains 32730 bytes avrdude: reading on-chip flash data:
Reading | ################################################## | 100% 6.76s
avrdude: verifying ... avrdude: 32730 bytes of flash verified
avrdude: safemode: Fuses OK (E:CB, H:D8, L:FF)
avrdude done. Thank you.
Using a Saleae Logic Analyzer, I sniffed the following USB communications. It seems to me that the atmega is transmitting properly but not receiving any responses but I am not certain.
I confirmed that the USB cable in use was working by plugging it into an Arduino Micro that I have. System was able to identify Arduino Micro, Arduino Uno and pololu AVRisp.
I am hoping that there is an easily assignable cause to the issues that I am experiencing. If any addition information is required, please ask.
dmesg
for errors when you plug the USB in.