M32U4 On a custom made board not responding

Other Hardware 3rd Party Boards
1

Hello,

The attached PDF's contain a design of a board I'm working on.
The design is based on Arduino Micro:
http://arduino.cc/en/Main/arduinoBoardMicro
Arduino Micro's schematic:

The data sheet of M32U4 can be found here:

I'm using usbtiny ISP programmer from sparkfun:

I have a few quotations regarding my failure in the first attempts to communicate with the board from the design:

  1. That is the first controller with a built-in USB port that I am working on, untill now I was used to connect to the ISP port and burn Arduinos' bootloader. Do I still need to use the ISP port to upload a bootloader or is it done by the USB port?

  2. I have tried to connet to the ISP port (MISO->MOSI, MOSI->MISO, SCK->SCK, GND->GND, RST->RST) via connector J3_Prog from the design, and run this avrdude command: "avrdude -c usbtiny -p m32u4" and recieved a failure (initialization failed, try -F...).
    The circuit is powered and the connections are good.

  3. I have tryed to connect to the USB port (D+->D+, D- -> D-, VUSB-VBUS,GND->GND) via connector J1_USB from the design and the computer does not make sound of atached USB device and nothing changes in device manager.

  4. The datasheet of the controller says:
    "All supplied parts are preprogramed with a default USB bootloader"
    What is the behavior of this bootloader? is there any pin I can measure to see if the program runs and is alive?

What is the correct way to integrate with this controller? USB or ISP?
Can you please see if there is a noticeable problem in the design for the lack of communication?

Any additional information will be given upon request.

Thank you in advance,
Roman.

biop_MCU_page.pdf (85.3 KB)

2

You need a bootloader to get the usb working.

The first thing to do is to connect avrdude with the chip with the MISO/MOSI interface.
Do you have a Leonardo or Micro board ? Test that first with your programmer.
You can use avrdude with the option -vvv to show a lot information.

What do yo mean by this: "The datasheet of the controller says: All supplied parts are preprogramed with a default USB bootloader".
That is not the Arduino bootloader, and I don't know if avrdude is able to connect to the preprogrammed bootloader.

3

The default bootloader is Atmel's DFU bootloader. Atmel's FLIP may be used with this bootloader or dfu-programmer an open-source command line program is also available. I think you need a driver for the dfu bootloader for windows to recognize it.

Master Slave
MISO <-- MISO
MOSI --> MOSI

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