SDsolar
  • Member for 5 years, 4 months
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How to have some code executed at a certain time of day with a DS3231 RTC?
5 votes

If you are getting 165:165:165 that indicates usually a problem with your I2C bus. But it might also be a power problem in the RTC. In any case, check your wiring. Your processor is simply not ...

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How do I use two I2C LCDs with 4 pins?
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4 votes

With the I2C backpack there are three pairs of landings, A0, A1, A2, which determine the 3 LSB of the device's address, using inverted binary. Left alone, they generate part of the F or 7 part of ...

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Moving motion sensor?
4 votes

OP didn't really specify the actual requirements other than detecting movement and wanting to use PIR while in motion. PIR (Passive Infrared) implies looking for warm bodies. In general, PIR ...

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Need assistance decyphering agriculture systems control code created by absent team member
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3 votes

Straight answer to the question as asked: To make it do this every 90 minutes would be if ((hours / 60 + minutes) % 90) == 0) { If you want something to happen every 5 minutes you would write it ...

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Can I include a header file into a new header file?
3 votes

Why not just include both in the final program? Happens all the time. DHT.h needs AdaFruit_Sensor.h, for instance, so you just include both. First AdaFruit then DHT

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How to power an Arduino Uno with 3 1.5V batteries?
3 votes

For battery-operated Arduino Uno's I recommend thinking bigger (in terms of power, not physical size). I power several by using 3x 18650 batteries in series, (providing about 14 Volts, connected to ...

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What is an easy way to power a 3.3v BMP-180 barometer board from a 5v Arduino Nano?
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3 votes

Here is the solution I settled on: a small part that will step 5 volts down to 3.3 volts. The price is right, but it will be shipped by the slow boat so will take a month or so to receive. 5Pcs 5V ...

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Does data coming in on Arduino serial port store for some time?
2 votes

Yes. The receive ring buffer is 64 bytes and will discard anything past that until the program reads them out of the buffer. But be careful: In serial monitor, any number of bytes more than 64 and ...

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Arduino Uno - relay with separate power
2 votes

This relay is designed to operate on 5V. Most commonly this will come from the Uno's 5v pin. If you want to externally power the relay itself then make sure to connect the +5 to the Vcc on the ...

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'tmElements_t' does not name a type
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2 votes

Clearly the compiler does not know what tmElements_t means. It is defined in TimeLib.h In your program you reference Time.h instead, where it is not defined. So: Change include <Time.h> to ...

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How do i power recycle on SD card
2 votes

I just read the USB2240 Part listing and it looks really handy for interfacing a PC to the flash. However, I believe you are taking the wrong approach by trying to power recycle it yourself. ...

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How to set Alarms on the DS3231 easily so the Nano doesn't have to go to sleep with delay statements?
Accepted answer
2 votes

Here it is: https://github.com/sleemanj/DS3231_Simple Example: https://github.com/sleemanj/DS3231_Simple/blob/master/examples/z2_Alarms/Alarm/Alarm.ino This is what I was looking for. My system ...

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Issue with HC-SR505 sensor
2 votes

You asked if anyone else has experienced this behavior, and from the documentation I can find the answer must be yes. The 505 holds the HIGH output for a certain amount of time. None of the ...

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How can I deal with rapid fluctuation of Anemometer readings?
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2 votes

A: Use a running average In the initialization I include an array to hold 10 values // Wind Speed Anemometer const int sensorPin = A3; int sensorValue = 0; float sensorVoltage = 0; float windSpeed =...

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Why is my TMP35 giving me weird values?
1 votes

I use voltage dividers a lot and have seen this before. In each and every case where ALL my readings are high, yet they vary predictably (like on my solar panels - they go up during day and down at ...

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Is it better to use #define or const int for constants?
1 votes

For variables of a specified type which are not altered during execution, either can usually be used. For Digital pin numbers contained in variables, either can work - such as: const int ledPin = 13;...

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Serial uart communication issues
1 votes

I often have this issue with my data-loggers. They use Nano or Uno to send readings to the Pi3 Python programs. My Arduinos send data every 60 seconds. Then the Pi adds a date and time stamp and ...

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Powering Arduino Uno from 5V pin, what exactly is the voltage range/tolerance?
1 votes

You don't say why you want this information, but there are others who are trying to do similar. (Starting with NOT destroying their Arduino) For instance, at the end of the article 10 Ways to ...

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Two sensors on one input
1 votes

The OP does not specify whether the focus is on hardware or software. So I will presume that what the professor might looking for is a solution using minimal circuitry; as close to the diagram as ...

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Cannot find COM port for Arduino after replacing Atmega328p
1 votes

Generally the IDE will detect one it can use, so you shouldn't need to use the Device Manager. When you select the board type, so far, so good. Then when you ask it to pick the port, it will present ...

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How to read data from Arduino with Raspberry Pi via I2C?
1 votes

You might want to graduate to the pigpio library for the Pi side of this. Here is where you can find examples of how it works. here is a fun one that is like Wireshark - will show you the I2C ...

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How can Arduino know Wire.available() is true or false?
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1 votes

The simple answer is that the Arduino Wire library has an internal buffer, and it can bring in characters and have them sitting there ready for you to pick them up. It can also sense a total ...

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Ultrasonic sensor returns random values on external power supply
1 votes

Glad the library helped. I think perhaps the problem had to do with reference voltages. If you are using two supplies, you need to make sure they are grounded together very well. One library ...

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Nano clone not working over USB, no data, no power, but can power via Vin (CH340 chip? schottky diode?)
1 votes

Either you have a cable problem or that board is just not working well. What you call the CH340 chip - when they go bad you get power but NO communications, in my experience. You can test voltages ...

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I want to build a radar alert system with Arduino
1 votes

ANSWER BASED ON YOUR TITLE: Here is a microwave RADAR motion-sensing module that you might find useful. You could mount it right by the stairs. http://www.ebay.com/itm/262662221979 LFS-DC04 2....

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Arduino Temperature sensor with a LED
1 votes

Your logic is backwards. Your program says if the temp is LESS THAN max then turn on the LED. But worse than that, you should not use pin 1. Pick any other pin.

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Multiplying the voltage output
1 votes

Assuming the 0-5 Volts is supposed to switch the output, in which case you want a program to control your output, then you will want to use a digital output pin to either switch a relay or a ...

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How to code Arduino to follow schedule
1 votes

Check out how the DS3231 Alarm functions work. They will interrupt even a delay() statement. At the appointed time the specified function is called. This same question was answered here: How to ...

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How can I use my Arduino sketches on my Raspberry Pi IDE?
Accepted answer
1 votes

To fix this problem I came up with the following procedure which takes out all the underscores from the directories & filenames and capitalizes each word instead. First, I copied all my sketches ...

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How cold or hot can my Arduino Uno get?
1 votes

I agree with the advice to read the data sheets, but here is a personal answer to the question. I installed a Raspberry Pi in an enclosure in which the existing Arduino survived last summer. ...

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