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1500 questions
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1 answer

Why does an LED sometimes flash when increasing brightness?

This is admittedly a cross-post from LED fade malfunction (random flash) but I can't get an answer on the Arduino forum. I was mucking around with some very basic code and I noticed that when repeatedly holding an LED at 0 brightness for 1 second…
Adrian
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1 answer

Why are Arduino clones cheap?

You can buy Arduino Nano v3 clones from Alibaba at the cost of roughly $2-$3. I have calculated the cost for fabricating and all the parts in the BOM for Arduino Nano V3, and it ended up costing around $10 to $12 (depending on where you fabricate…
40pro
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How do I remotely acquire data from Arduino based portable device?

I am making a device which will have an Arduino board and a sensor attached to it. The sensor will acquire data every 10 minutes and the data will be uploaded to my server. The size of every upload is about 200 characters. I'd like this device to…
Rutvij Kotecha
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2 answers

What's the most accurate way to time-stamp analogRead data?

I want to sample an Analog sensor as fast as possible, and time-stamp each sample that I take as accurately as possible. Currently, I'm doing the following: val = analogRead(SENSOR_PIN); clocktime = micros(); writeData(val, clocktime); // writes…
Josh
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2 answers

Why is my TMP35 giving me weird values?

A TMP35/36/37 is giving very high voltage readings, which results in high temperature readings. The serial monitor looks like this: As you can see, the sensor value is in the 900s, voltage is almost 5, and temp is in the 400s. The circuit is very…
MICROexchange6
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5 answers

LEDs: difference between common anode and common cathode?

What is the difference in using a common anode and common cathode of the 7 Segment in interfacing with the Arduino? How can you change the code if we need to add another 7 Segment display? How can you change the code to have a counter in backwards…
user13535
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2 answers

bootloader uploading into Atmega328

Here is mine circuit. Intially i used arduino UNO directly for programming. Now i am Using atmega 328 IC for programming. I am trying to connect 32 hall sensor via Mux circut. I wanted to How to upload boot loader or HExfile Here. Will avr pocket…
AMPS
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5 answers

Is it possible to transmit using an NRF24L01+ without an Arduino?

I have two NRF24L01+ modules which are transceivers, but for my project I would like to send a very simple signal from one of these modules to the be read by the other. That would've been very simple if I had an Arduino on each side but due to power…
Ceottaki
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10 answers

avrdude: stk500_getsync(): not in sync: resp=0x00

I have arduino pro mini 5V, 16M ATMega328 and CP2102 USB to TTL. I've wired them like this: When I try to upload a sketch to the arduino board I'm getting the following error: avrdude: stk500_getsync(): not in sync: resp=0x00 The board type and…
Deepsy
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1 answer

Connecting breakout board to Arduino with UART

I'm using a DigiX (Arduino Due based 3.3V) board to connect to a GPRS/GSM SIM908 breakout board. The SIM908 EVB board has the following pins on its RS232: I've got all three UART TX lines hooked up to the RX Lines (and RX to TX) on my Arduino but…
user2757902
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2 answers

Why is that any sensor signal need to be hooked up to the interrupt pins on Andruino boards?

I have come across some Andruino Sensors like Motion, Light and all recommend to be connected to pin 2 or 3 on Andruino Uno board which are interrupt pins. This is especially true if you are looking for HIGH or LOW values. Why is that to be…
user3646338
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2 answers

What is the circular gold pad on arduino mega 2560 v2 and above?

Could someone point me to the documentation that describes the gold dot and surrounding gold circle on the front of my arduino mega v2 board. It is right above the ICSP header and reset button, and directly underneath the letter 'U' in the silk…
Nate
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6
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2 answers

Formula / calculation of the function random() / randomSeed()

In which file can I find the calculation that is called with random()? If it is not too much could you also post the content in your answer? I am using an Arduino Uno and its standard IDE. I found this in the "WMath.cpp" but that is not the final…
kimliv
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1 answer

Low Power library messing up serial text

I noticed something unusual using the Low Power library today. When printing text in the loop and using LowPower.powerDown(SLEEP_1S, ADC_OFF, BOD_OFF); to sleep for one second, all the text in the loop gets messed up in the Serial Monitor as if you…
qwertz
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3 answers

Arduino digitalWrite 1 or 0 instead of HIGH or LOW

Is it ok to use digitalWrite(pin, 1) instead of digitalWrite(pin, HIGH) or digitalWrite(pin, 0) instead of digitalWrite(pin, LOW) I want it that way to make the coding lesser because I save values on EEPROM with 1's and 0's. So if I want to use…
Sam San
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