hello guys. i have this part of my code below which causing slow output on serial monitor. i thought it was because of delay function so i removed it out but it is still the same. i am thinking maybe it is beacuse of while. i know it should be some unblocking structure but i couldn't find what i can put instead. i used if but it kept writing the 1 command and never changed. what can i do? i am not sharing rest of the code because i think it is irrelevant but i if you wish i can. thank you.
unsigned long start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)1);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)3);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)1);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)4);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)1);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)3);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)2);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)3);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)2);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)4);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)0);
//delay(20);
}
PaulRB
February 14, 2025, 10:39am
2
Your question is about slow output on serial monitor. Nothing in the code you posted outputs anything to serial monitor. So the code you posted is irrelevant to your question. Only the complete code would be relevant. Please read the forum guide in the sticky post before you post again.
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)2);
//delay(20);
}
Your while loops will take the same time to execute with or without the delay() function. Without the delay() function, data will be written to whatever motorControlChar is more frequently.
3 Likes
It appears that you do not fully understand what you are doing. You have chosen not to provide the necessary information to answer your question, leaving us to guess the location of the print statements.
2 Likes
The code that you provided is blocking code. while (millis() - start < 2000) will block any other processing of code for two seconds. Next 700ms, next 2 seconds again and so on.
There are a number of topics on the forum that will help you to solve the problem; except the first one all come from the tutorial section of the forum.
1 Like
I didn't share the rest because the slowdown happened after i add this part of the code. but if it will be helpful, here is the whole code. thank you.
#include <ArduinoBLE.h>
//PASTEBEGIN
#include <Arduino_LSM9DS1.h>
//PASTEFINISH
// ------------------------------------------ BLE UUIDs ------------------------------------------
#define BLE_UUID_PERIPHERAL "19B10000-E8F2-537E-4F6C-D104768A1214" //please change to a unique value that matches BLE_IMU_PERIPHERAL
#define BLE_UUID_CHARACT_LED "19B10001-E8F2-537E-4F6C-E104768A1214" //please change to a unique value that matches BLE_IMU_PERIPHERAL
#define BLE_UUID_CHARACT_GYROX "29B10001-E8F2-537E-4F6C-a204768A1215" //please change to a unique value that matches BLE_IMU_PERIPHERAL
#define BLE_UUID_CHARACT_GYROY "39B10001-E8F2-537E-4F6C-a204768A1215" //please change to a unique value that matches BLE_IMU_PERIPHERAL
#define BLE_UUID_CHARACT_GYROZ "49B10001-E8F2-537E-4F6C-a204768A1215" //please change to a unique value that matches BLE_IMU_PERIPHERAL
//PASTEBEGIN
#define BLE_UUID_CHARACT_ACCA "59B10001-E8F2-537E-4F6C-a204768A1215" //please chnage to a unique value that matches BLE_IMU_CENTRAL
#define BLE_UUID_CHARACT_ACCB "69B10001-E8F2-537E-4F6C-a204768A1215" //please chnage to a unique value that matches BLE_IMU_CENTRAL
#define BLE_UUID_CHARACT_ACCC "79B10001-E8F2-537E-4F6C-a204768A1215" //please chnage to a unique value that matches BLE_IMU_CENTRAL
#define BLE_UUID_CHARACT_MAGK "89B10001-E8F2-537E-4F6C-a204768A1215" //please chnage to a unique value that matches BLE_IMU_CENTRAL
#define BLE_UUID_CHARACT_MAGL "99B10001-E8F2-537E-4F6C-a204768A1215" //please chnage to a unique value that matches BLE_IMU_CENTRAL
#define BLE_UUID_CHARACT_MAGM "09B10001-E8F2-537E-4F6C-a204768A1215" //please chnage to a unique value that matches BLE_IMU_CENTRAL
//PASTEFINISH
//begin
BLEService motorService("19B10000-E8F2-537E-4F6C-E104768A1214");
BLEByteCharacteristic motorControlChar("19B10001-E8F2-537E-4F6C-D104768A1214", BLERead | BLEWrite);
//end
// ------------------------------------------ VOID SETUP ------------------------------------------
void setup() {
Serial.begin(9600);
while (!Serial);
// configure the button pin as input
pinMode(LED_BUILTIN, OUTPUT);
// initialize the BLE hardware
BLE.begin();
Serial.println("BLE Central - Gyroscope control");
// start scanning for peripherals
BLE.scanForUuid(BLE_UUID_PERIPHERAL);//
}
// ------------------------------------------ VOID LOOP ------------------------------------------
void loop() {
// check if a peripheral has been discovered
BLEDevice peripheral = BLE.available();
if (peripheral) {
// discovered a peripheral, print out address, local name, and advertised service
Serial.print("Found ");
Serial.print(peripheral.address());
Serial.print(" '");
Serial.print(peripheral.localName());
Serial.print("' ");
Serial.print("' ");
Serial.print(peripheral.advertisedServiceUuid());
Serial.println();
if (peripheral.localName() != "BLE_IMU") {
return;
}
// stop scanning
BLE.stopScan();
LED_IMU(peripheral);
// peripheral disconnected, start scanning again
BLE.scanForUuid(BLE_UUID_PERIPHERAL);
}
}
// ------------------------------------------ FUNCTIONS ------------------------------------------
void LED_IMU(BLEDevice peripheral) {
// connect to the peripheral
Serial.println("Connecting ...");
if (peripheral.connect()) {
Serial.println("Connected");
} else {
Serial.println("Failed to connect!");
return;
}
// discover peripheral attributes
Serial.println("Discovering attributes ...");
if (peripheral.discoverAttributes()) {
Serial.println("Attributes discovered");
} else {
Serial.println("Attribute discovery failed!");
peripheral.disconnect();
return;
}
// retrieve the LED characteristic
BLECharacteristic ledCharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_LED);
BLECharacteristic gyroXCharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_GYROX);
BLECharacteristic gyroYCharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_GYROY);
BLECharacteristic gyroZCharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_GYROZ);
//PASTEBEGIN
BLECharacteristic accACharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_ACCA);
BLECharacteristic accBCharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_ACCB);
BLECharacteristic accCCharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_ACCC);
BLECharacteristic magKCharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_MAGK);
BLECharacteristic magLCharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_MAGL);
BLECharacteristic magMCharacteristic = peripheral.characteristic(BLE_UUID_CHARACT_MAGM);
//PASTEFINISH
//begin
BLECharacteristic motorControlChar = peripheral.characteristic("19B10001-E8F2-537E-4F6C-D104768A1214");
//end
// check if an specific BLE characteristic exists
if (!ledCharacteristic) {
Serial.println("Peripheral does not have LED characteristic!");
peripheral.disconnect();
return;
} else if (!ledCharacteristic.canWrite()) {
Serial.println("Peripheral does not have a writable LED characteristic!");
peripheral.disconnect();
return;
}
//begin
if (!motorControlChar) {
Serial.println("Peripheral does not have motor control characteristic!");
return;
}
//end
int buttonState = 0;
float x, y, z, a, b, c, k, l, m;
while (peripheral.connected()) {
// while the peripheral is connected
// read the gyroscope values
gyroXCharacteristic.readValue( &x, 4 );
gyroYCharacteristic.readValue( &y, 4 );
gyroZCharacteristic.readValue( &z, 4 );
//PASTEBEGIN
accACharacteristic.readValue( &a, 4 );
accBCharacteristic.readValue( &b, 4 );
accCCharacteristic.readValue( &c, 4 );
magKCharacteristic.readValue( &k, 4 );
magLCharacteristic.readValue( &l, 4 );
magMCharacteristic.readValue( &m, 4 );
//PASTEFINISH
Serial.print(millis());
Serial.print('\t');
Serial.print(x);
Serial.print('\t');
Serial.print(y);
Serial.print('\t');
Serial.print(z);
Serial.print('\t');
//PASTEBEGIN
Serial.print(a);
Serial.print('\t');
Serial.print(b);
Serial.print('\t');
Serial.print(c);
Serial.print('\t');
Serial.print(k);
Serial.print('\t');
Serial.print(l);
Serial.print('\t');
Serial.println(m);
//PASTEFINISH
//begin
//end
//begin
unsigned long start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)1);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)3);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)1);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)4);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)1);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)3);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)2);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)3);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)2);
//delay(20);
}
start = millis();
while (millis() - start < 700){
motorControlChar.writeValue((byte)4);
//delay(20);
}
start = millis();
while (millis() - start < 2000){
motorControlChar.writeValue((byte)0);
//delay(20);
}
//end
// make the LED blink
if (buttonState == 0)
{buttonState = 1;}
else if (buttonState == 1)
{buttonState = 0;}
digitalWrite(LED_BUILTIN, buttonState);
if (buttonState == 0) {
// write 0x01 to turn the LED on
ledCharacteristic.writeValue((byte)0x01);
} else {
// write 0x00 to turn the LED off
ledCharacteristic.writeValue((byte)0x00);
}
}
Serial.println("Peripheral disconnected");
}
1 Like
b707
February 25, 2025, 9:47am
6
As was mentioned above, your code from the start of the thread is a blocking code. Even though you are using millis(), you are doing it wrong. Your code from the beginning of the topic contains a six while loops with a timeout of 2000 milliseconds and a five with a timeout of 700 mS of each. Accordingly, this code is equivalent to inserting a delay of 15.5 seconds. I assume that this is the delay you see when outputting to a serial.
1 Like
ledsyn
February 25, 2025, 9:58am
7
Thanks for posting the sketch.
Serial 9600, you can use higher speed, 115200 shouldn't be a problem.
1 Like
yes, that's true. the delay is about 16 seconds. how can i rearrange this part of code? thank you.
PaulRB
February 25, 2025, 6:14pm
10
fellasfellas:
Serial.begin(9600);
Well, there's one thing you could easily improve. 9600 baud was cutting edge back in the 1980's. I generally use 115200.
EDIT: @ledsyn already mentioned this
PaulRB
February 25, 2025, 6:27pm
11
At mentioned by others, you need to implement a state-machine.
The reason is, your Arduino has, as far as we know, one CPU core and no operating system to support multiple processes running simultaneously on a single core. So if you write "blocking code", nothing can be written to serial monitor until the blocking code has finished executing.
Blocking code is what beginners write. Like drawing with wax crayons or riding a bicycle with stabilisers ("training wheels"). It's time to level-up your coding skills. The forum will be glad to help you get there!
system
August 24, 2025, 8:17pm
13
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.
