Posts: 4689. Arduinoでus（マイクロ秒）間隔のパルスを作る方法 背景 loopでdelayMicroseconds関数を利用してパルスを作っていたところ、同時に別のタスクもさせたくなったので、loopの外部でパルスを作る方法を探してみました。. Everything seemed to be working well in my simulations, but whenever I built the circuit and looked at the timing on an oscilloscope all of my uS values seemed to be off. ArduinoTo use PinFlasher, create a PinFlasher instance that specifies the output pin to flash and the whether on is HIGH (default) or on is LOW e. For delays longer than a few thousand. The ROM function ets_delay_us() (defined in rom/ets_sys. g. Pauses the program for the amount of time (in microseconds) specified as parameter. 25 and 0. Dominik2 October 29, 2017, 9:58pm #2. I chose the ESP32 because of its 240MHz clock, but it still seems to be having trouble. Just like delay () has a microsecond-version called delayMicroseconds (), millis () has micros (). e esp_timer_get_time() return a int64_t value and is parsed as uint32_t in delayMicroseconds(). This could change in future Arduino releases. print () function will also make the Arduino stop until the entire message has been printed to the serial monitor at the slow communication speeds of the serial interface. In general, it works already, but the servos are vibrating all the time. Wir können nicht garantieren, dass delayMicroseconds () genau für kürzere Verzögerungszeiten funktionieren. The Arduino UNO R4 Minima has a built in DAC (Digital-to-analog Converter) which is used to transform a digital signal to an analog one. There are a thousand microseconds in a millisecond, and a million. In this tutorial, I’ll show you a couple of methods to implement STM32 delay functions both in microseconds and milliseconds. Your stepX () function looks like this: void stepX () { currentMicros = micros (); // conditionally do some stuff. On a standard servo, this will set the angle of the shaft. Arduino: What is the difference between delay() and delaymicroseconds()Helpful? Please support me on Patreon: than. Pauses the program for the amount of time (in microseconds) specified as parameter. The standalone would give me the required functionality using the delay() function for delays between 3 milliseconds and 1 millisecond. 非常に小さい遅延時間に対しては、delayMicroseconds()の精度は保障できない。大きい遅延時間を指定すると、実際には極端に短い遅延を生成するかもしれない。 Arduino 0018以降から、delayMicroseconds()は割り込み禁止にしない。 参照 オリジナル. When you call delay, it keeps the timer running sending pulses during the wait. 本Lessonは【計量・重量センサ】について。2つの部品から構成。ロードセル、ADコンバータ。」ロードセルは量やトルクなどを検出するセンサ。アルミ起歪体にひずみゲージがホイートストンブリッジ回路構成で貼りつけられており荷重に応じた電圧をリニアに出力します。このセンサとArduinoを. So, you have to do something more like: for ( n = 1; n< 50; n++ ) { digitalWrite (pin, HIGH ); delayMicroseconds ( 2000 ); // send a 2ms pulse. Anmerkungen und Warnungen. Jumper wires. The timer setup is documented in wiring. My goal is 0-400 Hz controlable frequency, adjustable with a potentiometer. Currently, the largest value that will produce an accurate delay is 16383. The main caveat is that the argument has to be a compile-time constant. micro có kiểu dữ liệu là unsigned int. int outPin = 8; // digital pin 8 void setup() { pinMode(outPin, OUTPUT); // sets the digital pin as output } void loop() { digitalWrite(outPin, HIGH); // sets the pin on. This means that the functions’ return values will start all over from zero. The Time1. Pito's answer works, but more importantly, do you understand why it works? Also, the #include directive was never intended to be used with source code files (e. On 16 MHz Arduino boards (e. The delayMicroseconds () function will provide accurate delays as may be needed for some types of applications (e. More knowledgeable programmers usually avoid the use of delay () for timing of events longer than 10’s of milliseconds unless the Arduino sketch is very simple. digging around I found that the problem was the delayMicroseconds() function which only catered for 8MHz and 16MHz clocks. digiatlWrite (pin. The way the Arduino delay() function works is pretty straight forward. Now, delay () only takes integers, but I need a higher resolution. 1 KHz. I'd like to see the code, please, of an analog reading taking 100us and the code used to measure the time of the ADC reading. All without using the delay() function. The micros () function counts in microseconds, which is a lot smaller than milliseconds, and it repeats every 70 minutes. timerBegin. This question reminded me I've been curious about how to change the Arduino PWM frequency, but never bothered to look hard enough. The Arduino millis () is a timer-based function that returns to you the time elapsed (in milliseconds) since the Arduino board was powered up. </p> </div> <div dir="auto"> <p dir="auto">Currently, the largest value that. Graphs: [Attached. A digital servo needs a pulse of 1. This feature can be used to build a plethora of fun audio projects, but also work as professional lab equipment as a cheap function generator, for example. Learn how to compute the duration of any action in your Arduino program - using the micros() function to get the time. I use two OLIMEXINO 85 to implement a 2 channel remote control and control 2 digital servos. Once downloaded, start the Arduino IDE then go to Sketch > Include Library > Add Zip Library. e. example of code I'm using. The digitalWrite () function takes a substantial portion of your 20. functions. This library allows an Arduino board to control RC (hobby) servo motors. To change it unblocking you must in the loop, in each round: if btn pressed store the pressMillis, lit the led. The same technique can be used with micros(). When you read the datasheet of the HC-SR04 you will see that it needs a 10us trigger pulse. For my project I need to measure time in nanosecond fineness. The first delay of 2us is to make sure we are at an established LOW level on the trigger pin, since the pin might have been HIGH before that. . This is the second part of a series of ESP-IDF tutorials that I will complete as I learn stuff. If you really want it to return something you could use this: long int timeLoop (long int startMillis, long int interval) { // the delay function while (millis () - startMillis < interval) {} return millis () - startMillis; } But it really isn't needed. If you need better resolution, micros () may be the way to go. While these functions are easy, your program can not do other work during the delay. A partir da versão Arduino 0018, delayMicroseconds () não mais desativa interrupções. A partir da versão Arduino 0018, delayMicroseconds () não mais desativa interrupções. I would want a Timer Interrupt for the task you describe. The issue is that the Labview will work randomly. */ void delayMicroseconds (unsigned int us) { // calling avrlib's delay_us () function with low values (e. They are all 64-bit (54-bit for ESP32-C3) generic timers based on 16-bit pre-scalers and 64-bit (54-bit for ESP32-C3) up / down counters which are capable of being auto-reloaded. compare if currentMillis-pressMillis > 8000, if then shut the led. The maximum value it can take is 4,294,967,295 or 49 days. The interval is specified in microseconds, which may be an integer or floating point number, for more highly precise timing. 1 Answer Sorted by: 10 The source code for this function is fairly well documented and can be found in. 이 함수는 3 마이크로 초 이상 범위에서 매우 정확하게 돌아간다. This could change in future Arduino releases. inotplayingrn: duration = pulseIn (echoPin, HIGH); Please READ the documentation on the pulseLn () function call. This. Hi, I've been working with an Arduino at 1Mhz (using the internal 8MHz clock and the divide by 8 option). It took 1060 microseconds to execute the lines of code before the micros () function. In your case, it will be the equivalent of: delayMicroseconds (2); because the conversion of a float to an int is simple truncation. delayMicroseconds () delayMicroseconds ()関数はパラメータとして指定された時間分だけプログラムを一時停止します。. For delays longer than a few thousand microseconds, you should use delay () instead. You should explicitly declare your delay value as an. This functions returns true if successful. All good so far, using the delay command I can read frequencies up to 494 Hz, with the delay 1 microseconds. This could change in. SPI in STM32F103C8. Pauses the program for the amount of time (in microseconds) specified as parameter. 5%. Add a comment. Note that, there are a few cycles between the delays, so as you get shorter timeperiods, you will get less and less accuracy. Instead, #include preprocessor directives should be used with header files (. Instead you use your initial ISR to configure and enable one of the ATMega's Timer peripherals. The Arduino UNO R4 Minima has a built in DAC (Digital-to-analog Converter) which is used to transform a digital signal to an analog one. txt files . (Like measuring the travel time of radio waves in air). 23 kHz on pin D9. Diese Funktion arbeitet im Bereich von 3 Mikrosekunden und mehr sehr genau. You can call micros () to find the elapsed time to microsecond resolution. *; import processing. 050. e: 10:50:30. All variables used to hold millis or micros should be unsigned long. While delayMicroseconds() directly uses the value of the hardware timer, delay() and millis() are handled by the ISR. This page is also. While delayMicroseconds () directly uses the value of the hardware timer, delay () and millis () are handled by the ISR. As of Arduino 0018, delayMicroseconds() no longer disables interrupts. Giới thiệu. If ESP Timers prove problematic, then I like your assembler-delay idea. I'm weighing two options for the software side of things - controlling the speed via DelayMicroseconds (as I've done using the borrowed code posted here) or learning to use the AccelStepper library. The Arduino programming language Reference, organized into Functions, Variable and Constant, and Structure keywords. I tried this sample code but the 50us pulse shifted left and right in the oscilloscope. It is possible that. delayMicroseconds () deaktiviert ab Arduino 0018 keine Interrupts mehr. Returns the number of microseconds since the Arduino board began running the current program. Basically, I found out that delayMicroseconds(x) delays (on Arduino UNO, 16MHz) 7 Clock cycles for (x = 0, 1) 14 Clock cycles Short for (x >= 2) I noticed a too quick delay on 'x = 2' case. If not, just use millis (). Currently, the largest value that will produce an accurate delay is 16383. These simple Arduino delay functions just wait a fixed amount of time. Não é possível assegurar que delayMicroseconds () irá funcionar corretamente para valores menores. There are a thousand microseconds in a millisecond, and a million microseconds in a second. The delay () function allows you to pause the execution of your Arduino program for a specified period. If the program needs to run longer than this, an extra counter might. The High Resolution Timer (ESP Timer) provided by FreeRTOS uses a 64 bit hardware timer. Plenz September 19, 2015, 9:45am 1. . Connect the VCC pin of the HC-SR04 to the 5V output on the Arduino. Among the functions available to it, the following can be highlighted: Scheduled execution every x milliseconds and even microseconds. For very precise delays, you can use delayMicroseconds(), up to 16383 us. They operate as a direct replacement for standard rotary servos. println(); } So, I have tried changing the value of x in sendPulse(). This could change in future Arduino releases. delay () is clock speed independent now, because it calling micros () which reads the timer. 20th Dec 2021 update: added PinFlasher class and example (included in SafeString library V4. 882 milliseconds. Depending on the clock speed, using digitalWrite could be taking a large part of that 10µs delay. ให้อัพโหลดโค้ดตัวอย่างข้างบนลงบอร์ด Arduino คำสั่ง delayMicroseconds จะหน่วงเวลา 1000 us หรือ 1000/1,000,000 วินาที ค่าจะวิ่งเร็วมากๆThe list of supported commands for ATtiny85 are pinMode () digitalWrite () digitalRead () analogRead () analogWrite () shiftOut () pulseIn () millis () micros () delay () delayMicroseconds () Logged. 5hardwarearduinoavrootloadersoptibootMakefile. Diese Zahl läuft nach ca. I did need a multiple MHz blink, and thus a nanosecond delay. This could change in future Arduino releases. Description. The actual range varies by manufacturer, model and, I believe, production run. For delays longer than a few thousand microseconds, you should use delay() instead. 2 Answers. Prescaler divides the Timer clock further, by the value that you input in the prescaler. 5 Hz one “cycle” takes 17391304,34 ns. There are a thousand microseconds in a millisecond, and a million microseconds in a second. delayMicroseconds (us)에 대하여 살펴보겠습니다. delayMicroseconds (0) delays far longer than expected. This means that, by the time the function returns, startMicros will be very close to the current time. You need ten bits to transfer one byte, println() adds two more chars to the output stream. pun intended. Hello I am using a TB6600 stepper driver using the code example below and it works fine but I need a way for it to work without using delayMicroseconds, because I don't want delays when I eventually start adding other functions. Note that, there are a few cycles between the delays, so as you get shorter timeperiods, you will get less and less accuracy. Se envía un tren de pulsos de un periodo de aproximadamente 100 microsegundos. No entanto, certas coisas continuam a acontecer enquanto a função delay () está controlando o microcontrolador, porque a função delay não desativa. Also, given most of the use cases of this call use. ino" file with it, as a second tab. The delay has to be configurable to sub microsecond resolution. example of code I'm using. At this stage, you should see new examples appear under the file menu, and the following code should compile. MartinL October 22, 2015, 8:47am 2. I guess the system timer runs with a resolution of 1 ms. (백만분의 1초) delay ()함수보다 더 짧은 시간동안 지연을 시킬 목적으로 이 함수를 사용합니다. Der zurückgegebene Wert ist immer ein Vielfaches. Currently, the largest value that will produce an accurate delay is 16383. I have downloaded board files into Arduino to enable me to program the attiny 25/45/85/chips at 1Mhz or 8Mhz. //delay_us (us); // for the 16. Some interesting info about delayMicroseconds(). Pauses the program for the amount of time (in microseconds) specified as parameter. For the inverter ill be using 3 PMOS and 3. Comparing SPI bus in Arduino & STM32F103C8 Blue Pill board, STM32 has 2 SPI bus in it while Arduino Uno has one. 6 version, not when using alpha1 or latest master version of the core. 예를 들어 특정 시간 간격으로 직렬 모니터에 일부 숫자를 인쇄해야 한다고 가정합니다. The minimum duration for. Blink without Delay - Arduino Tutorial. Now, the ESP32 is flashed with the new firmware. Hiện tại, giá trị. Certain things do go on while the delay () function is controlling the Atmega chip, however, because the delay function does not disable interrupts. We cannot assure that delayMicroseconds will perform precisely for smaller delay-times. 遅延を追加せずに数値を直接印刷すると、マイクロコントローラーが. On standard servos a parameter value of 1000 is fully counter-clockwise, 2000 is fully clockwise, and 1500 is in the middle. Currently, the largest value that will produce an accurate delay is 16383. They are meant as convenience functions where actual time values can be specified rather than a number of cycles to wait for. Also delayMicroseconds() is a possibility. Currently, the largest value that will produce an accurate delay is 16383; larger values can produce an extremely short delay. 096 KHz. Duemilanove and Nano), this function has a resolution of four microseconds (i. Before we overflow (about 71 minutes and. This number will overflow (go back to zero), after approximately 70 minutes. That is how other arduino boards work and a lot of code and libraries expect delay to work as per the documentation. Also keep in mind that the Arduino digitalWrite function is rather slow (it has to map the Arduino pin numbers to PORT/pin), so in your case it would be better to write to the PORT/pin directly. 5. cmaglie removed the New label on Feb 27, 2014. If x is 300, for example, the Serial monitor outputs "3016. On standard servos a parameter value of 1000 is fully counter-clockwise, 2000 is fully clockwise, and 1500 is in the middle. I want to measure the time elapsed between my two arduino using rx/tx module in microseconds. When you multiply the 16-bit signed integers 60 and 1000, you don't get 60000, but rather -5536. Returns the number of microseconds since the Arduino board began running the current program. I want to make a task that constructs and sends infrared commands. As of Arduino 0018, delayMicroseconds () no longer disables interrupts. It accepts a single integer as an argument. compare if currentMillis-pressMillis > 8000, if then shut the led. So I should I have sufficient time for the loopDelay to work, but it's not. 現在、正確な遅延. esp_timer set of APIs provides one-shot and periodic timers, microsecond time resolution, and 64-bit range. If you want to make your Arduino sleep for 1 minute, or for multiple minutes, then it’s quite easy. delay (200) = 2 Hz at the flow computer. pinMode (outPin, OUTPUT); // sets the digital pin as output. Certain things do go on while the delay () function is controlling the Atmega chip, however, because the delay function does not disable interrupts. Arduino에서 delayMicroseconds () 함수를 사용하여 마이크로초 단위로 지연을 추가할 수 있습니다. Arduino millis () Function. delayMicroseconds(delay1); mancera1979 April 1, 2022, 8:09pm 7. This discussion on sub-microsecond ESP timing seems well worth reading FYI. I believe that the Arduino Zero core uses the Systick counter for millis (), micros (), delay () and delayMicroseconds (), so all the counters: TC3, TC4, TC5, TCC0, TCC1 and TCC2 are initially free to use. here is what I use, based on some mods as suggested by a certain you a while ago ! of course changed your code a bit, and lengthened the delay loop, as it seemed a good idear at the time, but I cant remember what it is now !The 10k potentiometer is used to vary the speed of the BLDC motor, its output is connected to Arduino analog channel 0 (A0). To get 1 second delay, you need 1000000 cycles of 1us, so it means that you have to create an algorithm. After approximately 50 days (or a bit more than 49. cpp file. Download SafeString from the Arduino Library manager or from its zip file. However, be aware that micros() will overflow after approximately 70 minutes, compared to millis()‘s 50 days. The code is trying to deal with "overflow" and entering critical sections, which is totally unneeded. how can i re write this in millis so that its non-blocking i did the top part but i dont know what to do with the delaymicroseconds? unsigned long WaterWait = 4000; unsigned long Waterdelay =0; int trig = 12; int echo. 아두이노 0018 현재, delayMicroseconds() 는 더이상 인터럽트를 비활성화 하지 않는다. Anmerkungen und Warnungen. Servo - writeMicroseconds () Writes a value in microseconds (us) to the servo, controlling the shaft accordingly. How do I get millisecond and microsecond-resolution timestamps in Python? I'd also like the Arduino-like delay() (which delays in milliseconds) and delayMicroseconds() functions. This could change in future Arduino releases. The input of the delayMicroseonds () function is an unsigned integer, and the maximum number that we. h> void setup () { adc1_config_width (ADC_WIDTH_12Bit);. int outPin = 8; // digital pin 8. println (println = print line) function to print the value of millis. It works with the ( (float) (dutyCycle / 100) * 1023) when duty cycle is an integer because of the cast to float makes. Description. I have some code running as a FreeRTOS task on my ESP32. SofwareSerial bit banging) by disabling interrupts during its core delay code. Please note that you need to cast both sides of the relational operator, otherwise the difference is implicitly casted to unsigned again! Watch your proposed delayMicroseconds(). Begin calling the function. So you would need 8 dummy instructions to delay half a microsecond. Currently, the largest value that will produce an accurate delay is 16383. serial. g. たとえば、特定の時間間隔でシリアル モニターにいくつかの数値を出力する必要があるとします。. delay() is a blocking function. Certain things do go on while the delay () function is controlling the Atmega chip however, because the delay function does not disable interrupts. The ESP32 SoCs contains from 2 to 4 hardware timers. The Arduino delayMicroseconds. So, for example, to get exact milliseconds, you'd target option 2, 1KHz. At one million ‘ticks’ per second, we can do. Take the number of minutes, multiply it by 60 to get the number of seconds, and then multiply it by 1000 to get the number of milliseconds. However, delayMicroseconds() will function inside custom ISRs because it does not rely on interrupts. Bestimmte Dinge laufen jedoch weiter, während die delay () -Funktion den Atmega-Chip steuert, da die delay () -Funktion Interrupts nicht deaktiviert. As you can see I measure the time between two instants using esp_timer_get_time() (this funcion returns an uint64_t with the number of microseconds starting from the power up). This function works very accurately in the range 3 microseconds and up. In most examples you need to use delay techniques in the java environment but these all operate on the order of milliseconds (1000 microseconds). Nothing discussed actually creates a pulse tho. [imported] #576. I want to read analog signal via adc with sample rate about 48khz so when I read via adc and delay about 20us. Description Pauses the program for the amount of time (in microseconds) specified as parameter. Description. the value returned is always a multiple of four). Hi i'm new to AVR assembly language so i was trying to get delay function to create 1 ms , 100us, and 1us delays to do that i need to figure out what to replace nop's with below here (mainboard arduino uno r3 ATmega328 Thank you. This function will return timer structure if configuration is successful. A partir da versão Arduino 0018, delayMicroseconds () não mais desativa interrupções. When flashing the same code on an ATtiny85 with 1 MHz the us-delay is factor 8 too long. micro có kiểu dữ liệu là unsigned int. More knowledgeable programmers usually avoid the use of delay () for timing of events longer than 10’s of milliseconds unless the Arduino sketch is very simple. Description. We cannot assure that delayMicroseconds will perform precisely for smaller delay-times. 32 KHz. startMicros = currentMicros; } Since there is nothing that can block it, it will always execute very fast. Provide details and share your research! But avoid. Currently, the largest value that will produce an accurate delay is 16383; larger values can produce an extremely short delay. I believe that the Arduino Zero core uses the Systick counter for millis (), micros (), delay () and delayMicroseconds (), so all the counters: TC3, TC4, TC5, TCC0, TCC1 and TCC2 are initially free to use. Mô tả delayMicroseconds () Tạm dừng chương trình trong khoảng thời gian (tính bằng micro giây) được chỉ định bởi tham số. Have the interrupt call a function to delayMicroseconds(8 (or whatever duration)) (don't use delay inside of interrupts, it doesn't work; call a function instead). 1 hour = 60 minutes. I am using the ATMega328P at 11. You just have to compile and upload the following code to your Arduino board and start the timeline according to your requirements. Appendix A. 967295 seconds. delayMicroseconds() you can provide a number of microseconds to sleep. This number represents the time and is measured in microseconds. 5ms. First of all, you need to know what the millis() function does. As far as I understand the “delayUs( uint32_t delay )” has a minimum resolution of 500 microseconds. 1 minute = 60 seconds. delayMicroseconds(50); // pauses for 50 microseconds. delay (1) = 494 Hz at flow computer. I discovered this experimenting with a sound synthesis program with a variable for the. the value returned is always a. txt upload speed to match the change of =115200* (11059200/16000000). delayMicroseconds () incorrect. 0:15. Still, interrupts (e. Looking at delayMicroseconds (), it states that for this delay, a maximum of 16383 microseconds is possible for accurate timing. 70 Minuten über (Nullstellen). The Arduino Servo class keeps sending the last pulse every 20ms. H. This feature can be used to build a plethora of fun audio projects, but also work as professional lab equipment as a cheap function generator, for example. So is timer 2 responsible for the delay() and delaymicroseconds() on mega? No, Timer0 is used on the mega for millis() and micros(). delayMicroseconds(8000000) gives a strange result that isn't quite 1/8th of 8. Notice that the function is only accurate for a few discrete frequencies. For a more complete version that can handle various clock frequencies, see the delayMicroseconds() function from the Arduino AVR core. Wir können nicht garantieren, dass delayMicroseconds () genau für kürzere Verzögerungszeiten funktionieren. For delays longer than a few thousand. delayMicroseconds(micro); Thông số. Obviously I just do a quick work around like such:AUTHOR: Jacob Hylén. Second; Change the boards. */ void delayMicroseconds (unsigned int us) { // calling avrlib's delay_us () function with low values (e. delayMicroseconds()As a part of my project I need to generate 10 microseconds pulses with 10 milliseconds intervals. The prototype modules of spectrometers were driven by an Arduino controller. So I'm trying to create an energy meter device which will read power every minute and then send it every 5 minutes through a LoRa server, using an MKR 1300 arduino. For this application delayMicroseconds() works quite well as it can make steps of (approx) 1 uSec. 10000 usec and often used in the 0. For a normal Arduino @16MHz only the following code will be compiled: /* Delay for the given number of microseconds. Its resolution. Arduino Ultrasonic Example Code. 024 KHz. More knowledgeable programmers usually avoid the use of delay () for timing of events longer than 10’s of milliseconds unless the Arduino sketch is very simple. The demo Several Things at a Time illustrates the use of millis() to manage timing without blocking. } blocks the loop. 015% will be difficult to meet. We need to provide the HC-SR04 with a fitting trigger signal. Currently, the largest value that will produce an accurate delay is 16383. I've tried usleep and nanosleep but regadless of values they both last at least 100us! - measured using gettimeofday before and after. I've tried using other available libraries but they require inputs of 2 or 4 pin connections when I am using 3. The Arduino programming language Reference, organized into Functions, Variable and Constant, and Structure keywords. delayMicroseconds 가 작은 지연시간동안 정확히 수행한다고 보장할 수 없다. We’ve seen the HAL_Delay () utility in the built-in HAL libraries by STMicroelectronics. So, you have to do something more like: for ( n = 1; n< 50; n++ ) { digitalWrite (pin, HIGH ); delayMicroseconds ( 2000 ); // send a 2ms pulse. So depending upon the application you can use millis() or micros(). Which can be used to create a time base for various events in your applications (like LED blinking, short pulse generation, or whatever). The servo interprets the duration of the pulse, 700 microseconds in this case, as a position to move to. Arduino Stack Exchange is a question and answer site for developers of open-source hardware and software that is compatible with Arduino. There is a more important difference between the two functions other than the unit of time the accept as parameters the function delay() calculates time using the time interript of the arduino. In the example above code line delay (86400000); and delays (3600000); find. Both A(device 1) and B(device 2) are responsible for measuring a time delay accurately using a local clock. millis () is incremented (for 16 MHz AVR chips and some others) every 1. Set the duty cycle for each PWM signal. Pauses the program for the amount of time (in microseconds) specified as parameter. doesn't work with delays <1 ms. Data were transferred to the PC by USB serial port. – Dave X.