Please just work -Eric

A project log for Barnabas-Bot

An open-source educational robotics project that inspires elementary and middle school kids to invent through building their own robot

ericeric 06/03/2017 at 21:212 Comments

Hey guys,

Since I last talked to you I have still been trying to troubleshoot the ATmega328p, in particular burning a bootloader onto it. I successfully burned a bootloader onto another uno using an uno, which I just did as a sanity check to make sure I actually knew how to do that.

I also made a "breakout board" that essentially just had the bare minimum needed to burn the bootlosder onto the chip;

Unfortunately this did not work either. I suspect that the crystal is not properly soldered on to the board (it is an incredibly small component). Next week I need to thoroughly probe the traces to be absolutely sure that the issue is not there.

I have also ordered additional resonators to see if that may be the issue. One is essentially the same crystal I am using but is a through hole component, which will allow me to take the variable of soldering out of the equation. If I can successfully burn a bootloader using that crystal it will tell me that my current issues lie with the soldering. Whether I am damaging the component when I solder or am simply creating shorts, I am unsure. Hopefully the additional probing will give me additional insight.

Till next time,



David Levi wrote 06/04/2017 at 05:24 point

You need to put 22pf caps on either side of the crystal, they are required. This isn't a bypass thing, it's a phase/LC time constant thing.

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de∫hipu wrote 06/04/2017 at 04:07 point

What you could try is switching the programmer to a "slow clock" mode -- I discovered that I sometimes need to do that with new chips before I set the fuses on them to switch to a higher frequency.

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