Hi I have situation when I start arduino it run setup message twice, this message shows in serial monitor: "Set coeficents " "Set coeficents " After that I go to main loop and wait for serial input of 24 float numbers(see functon in code: void modArr). Here when I enter 24 numbers it take them but after that he puts 24 zeros again. When I send 48 numbers the he store them in array by name: static float coef[24]; Full code: #include #include #include static const uint32_t GPSBaud = 38400; static float coef[24]; // = {5.5, 3.75, 4.0, 3.95, 4.0, 4.1, 4.17, 4.22, 4.21, 4.13, 4.2, 4.23, 4.22, 4.19, 4.17, 4.17, 4.21, 4.21, 4.18, 4.16, 4.13, 4.16, 4.2, 4.23 }; static float kmh[24] = {10, 20, 25, 38, 50, 61, 72, 83, 95, 109, 119, 130, 142, 155,168, 180, 190, 202, 215, 220, 230, 241, 250, 260}; int spd=0; float spdCoef; int imp; TinyGPSPlus gps; AltSoftSerial ss; int phrase[3]; String stack=""; bool start = false; void setup() { Serial.begin(38400); ss.begin(GPSBaud); Serial.println("Set coeficents"); } void loop() { if(start==false){ if(Serial.available()>0){ modArr(coef, 24); start = true; } } if(start==true){ Serial.print(F("Brzina = ")); printFloat(gps.speed.kmph(), gps.speed.isValid(), 6, 2); Serial.println(F("Km/h")); Serial.println(); smartDelay(100); spd = gps.speed.kmph(); spdCoef = spdGps(spd); Serial.println(spdCoef); imp = spd * spdCoef; Serial.println(imp); Serial.println(coef[5]); Serial.println(kmh[5]); if (millis() > 5000 && gps.charsProcessed() 1) Serial.print('*'); Serial.print(' '); } else { Serial.print(val, prec); int vi = abs((int)val); int flen = prec + (val = 1000 ? 4 : vi >= 100 ? 3 : vi >= 10 ? 2 : 1; for (int i=flen; i kmh[i] && kmh[i+1]>spd) { int y = map(spdVal, kmh[i], kmh[i+1], coef[i], coef[i+1]); return y; } } } void modArr(float arr[], int sizeArr){ while (Serial.available() > 0){ for (int i=0; i<sizeArr; i++) { arr[i] = Serial.parseFloat(); Serial.println(arr[i]); Serial.println(i); } } }

When you upload a sketch it will run for about 150 milliseconds before the Serial Monitor connects. Serial Monitor has to wait for the uploader to close the serial connection before it can open the serial connection. When the serial connection opens, it resets the board. I've started adding a 200 millisecond delay after Serial.begin(); to make sure none of my sketch gets run between the time of upload and time Serial Monitor connects. This mostly causes problems when a sketch reads and writes EEPROM immediately on startup. For example, if you read a location in EEPROM, increment the value, and write it back, the behavior will show it incremented twice on each upload.

Hi, @milosk Welcome to the forum. Please read the post at the start of any forum , entitled "How to use this Forum". To add code please click this link; [image] How to get the best out of this forum IDE 1.x See also FAQ - Arduino Forum for general rules on forum behaviour and etiquette. Hello, Welcome to the Arduino Forum. This guide explains how to get the best out of this forum. Please read and follow the instructions below. Being new here you might think this is having rules for the sake of rules, but that is not the case. If you don’t follow the guidelines all that happens is there is a long exchange of posts while we try to get you to tell us what we need in order to help you, which is fru… What model Arduino are you using? Can I suggest Serial.begin(38400); to Serial.begin(115200); And change your IDE monitor to that baud rate. Thanks.. Tom.. :grinning: :+1: :coffee: :australia:

Hi Tom, thanks. I tried that :slight_smile: i used 9600 to 115200 but is same. I think also this gps antena can work on maximum 38400 so I left same baud at the end of antena and arduino uno. Chip is atmeg328.

This solved the problem... Thanks

[image] johnwasser: I’ve started adding a 200 millisecond delay after Serial.begin(); to make sure none of my sketch gets run between the time of upload and time Serial Monitor connects. Yes. I work with LEDs so my solution is to have a very small sketch open that turns off all the LEDs, I upload that while thinking about why I’ve gone wrong and near blinded myself. So that first 200 mS is not running the sketch I am working on. Edit: shower realization: that won't fix the double eprom bump, as my sketch will run whilst the turn-off sketch it being uploaded, doh! But it is handy to turn off the LEDs, like a strip you've accidently turned full on OMG those things be bright. a7

Double run setup

Projects Programming

TomGeorge April 24, 2021, 8:02am 2

Hi, @milosk
Welcome to the forum.

Please read the post at the start of any forum , entitled "How to use this Forum".

To add code please click this link;

What model Arduino are you using?
Can I suggest

Serial.begin(38400);

Serial.begin(115200);

And change your IDE monitor to that baud rate.

Thanks.. Tom..

Topic		Replies	Views
Setup running twice Programming	66	1461	November 2, 2026
Arduino IDE 2.3. No output Data from Setup Programming	28	569	October 13, 2025
How to get your Arduino to tell you its Serial baud rate Programming	33	955	January 11, 2026
Unexpected double output in setup() - Why??? Programming	22	7008	November 2, 2017
double output on setup observations Programming	4	1233	March 18, 2021

Double run setup

Related topics