is it alright, if i connect my mega2560 and R3 to tx and rx?

so basically, i was doing an test with my arduinos since im kinda new to this arduino stuff, and when i plugged my 2560 in first, it lit up and so did my arduino R3 which wasnt connected to a USB port. is this normal? does it damage anything? it really scares me since i dont want to damage my hardware
20 Replies
AnonEngineering
AnonEngineering4mo ago
all you have between the 2 boards are TX > RX and RX > TX and ground? wdym "R3 lights up"?
jsadhjdshgfsage
jsadhjdshgfsageOP4mo ago
yeah, the tx rx connected and GND the same. the R3 like gets a power supply and the ON light lit up. is it normal?
AnonEngineering
AnonEngineering4mo ago
i wouldn't expect the PWR LED on the Uno to light up with only those 3 connections
jsadhjdshgfsage
jsadhjdshgfsageOP4mo ago
i forgot to mention both had code too
AnonEngineering
AnonEngineering4mo ago
but as I understand it no power is going to the R3 (no USB) or Vin
jsadhjdshgfsage
jsadhjdshgfsageOP4mo ago
or it could be the R3's fault since i got it from temu lol
AnonEngineering
AnonEngineering4mo ago
does the R3 run "Blink" as you'd expect?
jsadhjdshgfsage
jsadhjdshgfsageOP4mo ago
what do you mean "Run" ?
AnonEngineering
AnonEngineering4mo ago
can you load the Blink example, once a sketch is loaded it "runs"
jsadhjdshgfsage
jsadhjdshgfsageOP4mo ago
sorry if i sound stupid, but can you like explain it in simpler terms? im new to this arduino stuff
AnonEngineering
AnonEngineering4mo ago
look in File | Examples | Basic | Blink, upload that example
jsadhjdshgfsage
jsadhjdshgfsageOP4mo ago
and i just post the code here?
AnonEngineering
AnonEngineering4mo ago
no, upload that example to your R3, if the LED blinks your R3 is fine
jsadhjdshgfsage
jsadhjdshgfsageOP4mo ago
its blinking
AnonEngineering
AnonEngineering4mo ago
ok, the Uno R3 is fine
jsadhjdshgfsage
jsadhjdshgfsageOP4mo ago
also i noticed a weird thing, in the normal R3 there is like a long line which is the microcontroller right? mine just has a singual cpu in the middle, is that normal?
AnonEngineering
AnonEngineering4mo ago
look closely at the chip, does it say Atmel328? (I bet it does) the "lnog" ones are "DIP" type, the square ones are surface mount
jsadhjdshgfsage
jsadhjdshgfsageOP4mo ago
it does say that
AnonEngineering
AnonEngineering4mo ago
sry for delays, i'm at work. I don't know why the power LED comes on, but nothing seems broken
Coder_DO_As_Impossible
Generally I've also seen R3 powering up like that, if you provide 5v supply to any of the digital pins, it turns on.

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