Bootloader burns just fine, uploaded simple program is not working #174
Description
``Hello, I am trying to get ATmega4809 on Arduino Nano Every working with serial programmer. Thing I have done:
- Removed level shifting transistors that connected SAMD11 used as UPDI programmer to Atmega4809, also removed pullup R on UPDI
- Created a working programmer from Arduino Nano with Atmega328P
- Burned bootloader Optiboot with serial3 on alternative pins (to match the Every Nano so I can use the PCB traces)
So my issue is - I can burn bootloader via Arduino Nano to the ATmega4809. When I dump the memory to a file, it is exactly what the bootloader hex from your code looks like. When I try uploading through serial (FT231X connected to mega4809 on Serial3 alt pins), it uploads just fine, reads just fine but the code simply does not run. I checked the fuses, dumped the hex (bootloader is still here, tried to upload also with no bootloader, whatever...). When I tried a sketch as simple as this:
`#include <Arduino.h>
bool test;
void setup()
{
pinMode(5,OUTPUT);
}
void loop()
{
delay(500);
test = !test;
digitalWrite(5,test);
}`
, it simply will not do anything. Tried using serialPrint, SSD1306 display, also nothing. Also I tried uploading with PlatformIO on VScode, it deletes the bootloader but the sketch gets uploaded, also does not work. When I purposefully "messed" the pin operations up in the code, on some versions the LED lit up with a very low current (I guess something got really wrong). Is there anything I forgot? I tried also not using the Arduino pinMode and digitalWrite functions, I just set the registers directly, with also no luck. Is there anything I am forgetting from the HW point? Do I need to add some resistors, etc? It drives me crazy as I have already written a long code that works on Nano Every, but I want to use my own boards and I do not want another chip (SAMD11) here. Thanks in advance!