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Topic: Arduino (MEGA2560) bricked after connecting GND and reset with a capacitor (Read 70 times) previous topic - next topic

dnhp1729

Hi,

I made a small project in which my Arduino (MEGA 2560) was keeping track of temperature changes. To allow to unplug it from the computer, and to retrieve all saved data (on serial port) later when plugging it again, I connected 'GND' and 'reset' with a capacitor (as described e.g. here).

But even after removing everything from the board, I am now unable to upload any sketch (the old sketch is still there and running...). I get the following error message:

avrdude: stk500v2_ReceiveMessage(): timeout

So, did I bricked this Arduino? Is there anything to do?
Thanks in advance for any hints!

sterretje

I assume that you removed the cap. Did you solder the capacitor? If so, check the area where you soldered.
How does the board react on a reset? A couple of flashes indicationg the bootloader is active?
Did you try to reset the board with the button when the IDE reports the memory usage; might take some practice.
Do you have a so-called FTDI cable or another Arduino that can be used as such.

Note:
You don't need a cap if you use a decent terminal program that allows you to control DTR (Realterm under windows is one of them but there are plenty more).
If you understand an example, use it.
If you don't understand an example, don't use it.

Electronics engineer by trade, software engineer by profession. Trying to get back into electronics after 15 years absence.

dnhp1729


-- The cap was removed (as everything else); nothing was soldered on, it's an Arduino board with pins to avoid any soldering.... (this one)

-- Not sure how the board reacts to reset: the program interrupts (I can see it because the LED 13 stops blinking, which was one of the features of the program) so it seems that the board is indeed resetting, but the usual short rapid blinking do not occur (the program resumes...)

-- I'll try to reset the board when the IDE reports memory usage... I´ll let you know.

-- I don't have a FTDI cable, but could buy one! I have a couple of Arduino nanos, what's your idea?

-- I'm on linux (but a total noob on Arduinos...). If you have any pointer to a way to avoid this capacitor trick in the future I'll take it and keep it precioulsy...

sterretje

1)
Regarding using a Nano

Short reset to ground to keep the 328P in reset
Nano Rx to Mega Rx
Nano Tx to Mega Tx
GND to GND

Connect Nano to PC, select its com port, select Mega as the board and try to upload

2)
Regarding using a Nano (2)

Use it as a ICSP programmer (Arduino as ISP) toeither burn the sketch or the boot loader

3)
In Linux, look at the options that minicom provides.
If you understand an example, use it.
If you don't understand an example, don't use it.

Electronics engineer by trade, software engineer by profession. Trying to get back into electronics after 15 years absence.

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