Problems with building my own Arduino uno

Hello everyone,

i wanted to build my own version of an Arduino uno as a nice smd soldering project. But after completing the build, i wasn´t able to upload the bootloader. I followed the official Arduino tutorial and also tried some other methods, but none of them have worked so far.

This is the Error Message I keep getting:

avrdude: stk500_initialize(): (b) protocol error, expect=0x10, resp=0x01
avrdude: initialization failed, rc=-1
Double check connections and try again, or use -F to override
this check.

The board itself can be seen here:
https://easyeda.com/nimmersatt222/arduino-340-v2

I made some modifications to the original Arduino UNO design but it should work.

Builder3000:
I made some modifications to the original Arduino UNO design but it should work.

But it does not work.

So what were the midifications, show us the modified schematic perhaps ?

What are you using to upload the bootloader ?

srnet:
So what were the midifications, show us the modified schematic perhaps ?

What are you using to upload the bootloader ?

I added:
-an additional 5v net, wich is not limited by a fuse, but the power net for the Atmega has still a 500mA Fuse.
-a usb type c port
-ws2812b Leds on the back

The schematic is available here:

Builder3000:
The board itself can be seen here:
https://easyeda.com/nimmersatt222/arduino-340-v2

Builder3000:
And I used another Arduino UNO (2 different ones) to program my board following the Arduino ISP tutorial:
https://www.arduino.cc/en/Tutorial/ArduinoISP

Try connecting a 10 uF capacitor between the reset and ground pins on the Uno you're using as an Arduino as ISP programmer.

I tried it with both of my Arduino UNOs, but sadly it didn´t work…

OP's schematic:

It appears you have made several changes:

  1. You've gotten rid of all the 100nF decoupling capacitors. That is going to cause you problems.
  2. You are using two parallel voltage regulators for the 5V net. Are you sure that it is ok to use those regulators like that?
  3. You haven't connected the CC pins of the USB-C connector, so the voltage coming in on VBUS will be +5V. For some reason you are trying to feed your +5V regulators from this supply which won't work. The fact that you're sending this supply through a diode means that the input voltage to the regulators will in fact be lower than +5V.

The bootloader failure appears to be a lack of interconnection between the reset circuit and pin 24 (C1) of the ‘328.

You also need to fix the issues pointed out in post #5. A lack of bypass caps is a complete show stopper.

WattsThat:
The bootloader failure appears to be a lack of interconnection between the reset circuit and pin 24 (C1) of the ‘328.

You also need to fix the issues pointed out in post #5. A lack of bypass caps is a complete show stopper.

Good catch, although unless I'm being exceptionally dense shouldn't the reset circuit be connected to physical pin 1 (PC6)?

BJHenry:
Good catch, although unless I'm being exceptionally dense shouldn't the reset circuit be connected to physical pin 1 (PC6)?

The 'schematic' shows a 328P-AU, so RESET is on physical pin 29 (PC6).

srnet:
The ‘schematic’ shows a 328P-AU, so RESET is on physical pin 29 (PC6).

And of course, after looking at that I can see that the RST net is in fact connected to that pin.

Thanks for all the replies!

I tried to update my schematic according to your suggestions.

Do you see another problem with my schematic?

First off, please see this guide to posting images directly in your post. You'll get more people seeing the actual schematic that way.

That updated schematic looks much improved. You do need a decoupling capacitor for every VCC and AVCC pin though.