If I can change it easily, then great! Thanks for looking. Let’s review some basic Arduino function jargon. To state it another way, the value that is returned by the function millis () is the amount of time that has passed since the Arduino board was powered up. I know one example online used that and got weird values for under 0, but the code below looks so nice I hate to toss it lol. When you call the millis () function, it returns the current value of the timer/counter in milliseconds (hence the millis () function name). If you add a line of code below that, then it wont work. IIRC this doesnt matter in C, but its just bad practice to do this. Controlling a relay module with the Arduino is as simple as controlling any other output as we’ll see later on.

Another note: You forgot a semicolon on your second to last line. A relay is an electrically operated switch that can be turned on or off, letting the current go through or not, and can be controlled with low voltages, like the 5V provided by the Arduino pins. This guide explains how to get the best out of this forum. Just pass a negative number of steps as an argument to motor.step(). It seems to me that the delay() function never works I tried using the millis() as well and it doesnt work so well neither. It is all to do with scoping ( C/C++ rules of when a variable is visible to other functions) and how the Arduino environment (although convenient) does hide what is going on behind the scenes - and this can catch you out. I also don't see 'unsigned' used for any variables. Hi all, I am using ESP32 to do a project by using delay() function. This Arduino delay gotcha is fairly subtle and you may have already come across it. These sensors use I2C or SPI to communicate, 2 or 4 pins are required. > Adafruit BMP280 I2C or SPI Barometric Pressure & Altitude Sensor STEMMA QT : ID 2651 : 9.95 : Adafruit Industries, Unique & fun DIY electronics and kits. Delay runs when you call it and it will NOT allow you to do anything else until it is done.

Is there an easy way to change it so that it works with negative numbers? I'm assuming the issue is with shifting bits around but I honestly don't know exactly where's at fault. Designed specifically to work with the Adafruit BMEP280 Breakout. when I saw Blink Without Delay article, it use millis function not delay function is it The Millis function runs at startup and does not block the processor from doing other functions. I'm using the following code and it works fine until it hits 0*C, then it gives out weird stuff.

Arduino delay negative