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3

I don't see a second power-supply in your photo. If you're trying to run the pump directly from an Arduino pin, it is highly likely that the pump needs way more current than the pin can supply. It may be possible to power the motor from the USB but 1) the Uno board doesn't make that readily available, 2) it puts your PC at some risk (of back-EMF or of over-...


2

I have a couple of suggestions: The combined code is very different from the simple LM35 code that works. I'd suggest you start with the combined code but comment out everything that doesn't directly apply to reading the LM35, and get that working correctly. The interrupt service routine (ISR) is trying to do too much, and leaves the interrupts off during ...


2

Easy, this is one of the simple projects used as an introduction to Arduino programming. You will find many versions of free code out there. below is an example and a total newbie step-by-step. Download Arduino IDE. Buy an MQ7, an Arduino or NodeMCU, a breadboard, a LED and some jumper wires and you are in business. Use the sketch below or google "MQ7 ...


2

A good way to start debugging this sort of problem is to print out debug statements that say what the hardware should be doing. If the debug statements print out as expected then it's probably hardware, if not, then it's probably your code, e.g. if (percent < threshold){ Serial.prinln("LED on."); digitalWrite(LED_BUILTIN,HIGH); } else { Serial....


2

I found the I2C address on my Eagletree Airspeed V3 sensor to be 0x75 NOT 0xEA. the following code adapted from first sample above works on my Nano: /* * note that timming is critical - see delay (5) * and bps set to 115200 * works ok, but clean up 5-19-2019 jaf */ #include <Wire.h> #define AIRSPEED_ADDRESS 0x75 #define WRITE_BIT 0x00 #...


1

The UGN3503 that you use gives out a analog voltage that changes when there's a magnetic field present. So this sensor needs to be connected to an analog pin. If there is no field present the voltage is around 2.5Volt. If the south pole of a magnetic field is present the voltage will be higher that 2.5V. With a north pole the voltage will be lower that this ...


1

Your approach is globally sound. However, the code that measures the input frequency is very time sensitive. Thus, you have to make sure this piece of code is never delayed by anything else. This means that everything in your sketch should be fast and non-blocking. I see a few instances of blocking behaviour you should get rid of: the call to delay() and ...


1

you could try 4 terminal sensing. I have not used it myself, but the basic idea is to try to normalise for some of the external factors you mention. As for the Arduino, the analog to digital converters have 10 bits of precision. This means you will get 1023 distinct values as the input voltage varies betwee 0 and Vmax (+5 or +3.3 depending upon the actual ...


1

-999 means that it didn't get a result from the DHT. You need to filter them out - which you are attempting to do, but wrongly. Your line of code: if((DHT.temperature || DHT.humidity) > -25) { is not doing what you thing it is. If you start from the inner most brackets and "reduce", you get: Is DHT.temperature or DHT.humidity? That makes no real ...


1

I think you're fine depends on the gyroscope model and lcd. -For ultrasonic sensor thats 2 pins -the lcd needs at least 6pins but with an i2c adapter you only need 2 pins -3 push buttons 3 pins -one pin for the buzzer Plenty of room left on the uno


1

You can see this one: SONIC-ANEMO-MICRO https://lcjcapteurs.com/en/girouette-anemometres-capteur-vent/sa-micro-2/


1

Frame challenge: pick a sensor that complies with your needs and specification - especially the performance characteristics you're interested in, e.g. range of wind speed to measure, required accuracy and resolution, response time and data acquisition rate, to name just a few. Don't look for something specific to Arduinos to not unnecessarily narrowing down ...


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