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This is a problem with the Arduino Mega board. On the Mega, D2 is not INT0 as it is on the Uno. It's INT4. There's a footnote in the spec sheet that says only level interrupt is supported. That means you can't use RISING, FALLING or CHANGE. Your only choice is to use LOW. So the Arduino will be woken up when the motion turns OFF, not on. That's why it's ...


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[library] = library name 1) edit the [library] library.properties file and add dot_a_linkage=true to the end ... (/home/name/Arduino/libraries/[library]/library.properties) 2) build the example ... 3) After the build is complete navigate to the build folder (In Linux it's located in the /tmp/arduino_build_xxxxxx folder) then copy the dot_a file from under ...


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Serial data can only go to one place at a time. Either your Python program can receive the data, or the Serial Monitor can receive the data. Similarly the serial port can only receive data from one place at a time. So Windows prevents you doing something invalid by locking you out of the serial port when something else is using it. This is normal, and ...


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Note that the Arduino function "map" is really this: long map(long x, long in_min, long in_max, long out_min, long out_max) { return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min; } ...so, if you pass a "minimum from" value which is less than the actual value you are mapping from you will get a negative number given your "minimum out" ...


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There exists 2.00 to 2.54mm adapters, like in this link. They look like below (example of 1.27, 2 and 2.54mm):


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I'd suspect that it is a software error. Did you check your circuit if it induces desync between the Arduink and the LCD, or did you just used the wrong drivers?


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Measurement sometime lost due to serial communications between Arduino and Simulink. So raw data have some glitches in output values. In order to solve the issue, we have to use state estimation to solve this problem.


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There is missing information. Assuming a 5V Arduino and all D0s and D1s swing from 5V to 0V as the Wiegand protocol defines. This despite the 12V power supply in the question's diagram. Examining the driver code on GitHub, we see it's falling edge interrupt driven. So any noise when the line is expected to be at a steady 5V will cause the driver to run. ...


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You need to declare it volatile in both places and shut off interrupts while reading it. The mainline has to read it byte-by-byte, and an interrupt could otherwise occur between any two byte-reads, rendering the result of the 4-byte read as garbage. 'volatile' informs the compiler that the variable might not contain what it did last time (which the ...


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the 328p is the microcontoller. It's the larger chip located in the middle of the arduino board surface. This one handles the code/ sketch/ programme that you write). The 16u2, on the other hand, is the smaller chip located near the USB port. This handles data communication through the USB port.


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You need to have both confirm button and a choice button pressed at the same time since d is not updated in the settings function. Something like this is better: void settings(){ if (a==LOW && b==HIGH && c==HIGH && d==HIGH){ //if BD is pressed while (a==LOW) a = digitalRead(BD); //wait for button release ...


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You have to use a relay that can handle minimum 415 volts (and keep some reserve). Also take the current/amperage into account (possibly use multiple relays).


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