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Topic: Custom 32u4 pcb program's fine, does not start. (Read 671 times) previous topic - next topic

L1N0_

Hi,

I've created a custom board using the Pro Micro eagle designs. After soldering the 32u4 get's programmed with ease using a USBasp (Leonardo). But after nothing, powering the board does, well nothing..

My mind is towards the crystal setup. When uploading/programming, do you use the crystal?
If so the crystal must be fine, i'm clueless. Any thoughts?

If not, what are the steps to check the crystal and how to continue?

I'm using a "Xtl,SMD,5032,16.000MHz,18pF,20ppm" from RS-online with 22pf capacitors and wired as a pro-micro. The capacitors connect trough a general ground plane, that is not ideal i'd guess?
There is no usb port available on the pcb.

Attached a verbose log and part of the schematic. Thanks for any pointers.

pert

But after nothing, powering the board does, well nothing.
This is too vague.

What is the program you have running on the board?

What is the expected behavior?

When uploading/programming, do you use the crystal?
It does require a clock source. The ATmega32U4 has an internal 8 MHz oscillator. It comes from the factory with the fuses set to use the internal oscillator as the clock. You need to set the fuses to use the external crystal. In the Arduino world, this is normally done via Tools > Burn Bootloader, which sets the fuses according to the configuration of the board selected from the Tools > Board menu in addition to burning the bootloader.

L1N0_

#2
Sep 02, 2019, 10:34 am Last Edit: Sep 02, 2019, 10:35 am by L1N0_
Vague, yes; Programming (bootloader, blink ed) proceeds fine. Any output after, no.

That's not really answering my question; does the 16mhz crystal get's used when uploading, programming, bootloader-ing? (the board i've selected, leonardo has a crystal) If so, the crystal must be fine. If not; i'll look into the crystal setup. (I'm aware of fuses and how to set them)


Are there any suggestions from the part's i've used? "I'm using a "Xtl,SMD,5032,16.000MHz,18pF,20ppm" from RS-online with 22pf capacitors and wired as a pro-micro. The capacitors connect trough a general ground plane, that is not ideal i'd guess?"

Best regards,

pert

That's not really answering my question; does the 16mhz crystal get's used when uploading, programming, bootloader-ing?
I thought I'd already answered that. The crystal gets used during uploading, programming, and bootloading if your fuses are set to use the crystal.

L1N0_

So the 16mhz crystal get's used with usbasp writing the bootloader and program usbasp upload.. The crystal should be fine then.

Still i'm unable to 'start' a program after burning a bootloader (Arduino ide) (fuses ed) and then uploading a simple blink sketch with a USBASP. The board jut does not budge. Only a SCK error when uploading, which should be fine.

I've made a second revision of the board using a crystal oscillator similar on the UNO aswel. Still, nothing.

Power? Check.
Pins connection? Check.

Are there any known or obvious steps i've should check? Would using a 328P (tqfp) be easier to manage?

pert

Are you sure you're checking the right pin for the blink? It's common for people getting started with working with bare microcontroller chips and Arduino to not understand the way Arduino pin numbers are mapped. Arduino pin numbers are arbitrarily assigned and don't necessarily have any relation to physical pin number or port bit number. For example, if your Blink sketch is blinking pin 13, that is PC7 on the chip.

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