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Topic: Real time clock (RTC) for system (Read 351 times) previous topic - next topic

Jack_Arsal

Hello..
i am working on a real time gestures controlled robotic arm in which i have to measure time intervals. and RTC is not accurately  count down specified time interval. and i have no idea what is wrong with this timer. Should i change my timer ? which timer should be used for this purpose.
Thank you.
Jack Arsal

Paul_KD7HB

Hello..
i am working on a real time gestures controlled robotic arm in which i have to measure time intervals. and RTC is not accurately  count down specified time interval. and i have no idea what is wrong with this timer. Should i change my timer ? which timer should be used for this purpose.
Thank you.
Jack Arsal
Jack, are you asking us to GUESS at which RTC you are referring to?

Paul

jremington

For informed help, please read and follow the directions in the "How to use this forum" post.

Smajdalf

What time interval and what precision do you need?
Common resolution for RTCs is whole seconds limiting precise measurement of short intervals. And it cannot be used for precise measurements of long intervals either due to crystal limited precision.
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Jack_Arsal

What time interval and what precision do you need?
Common resolution for RTCs is whole seconds limiting precise measurement of short intervals. And it cannot be used for precise measurements of long intervals either due to crystal limited precision.
exactly sir RTC is fail to limiting precise long time intervals what should i use to get long time intervals one more thing sir i also want to do cost analysis for this project so i need to use cheep and healthy timer

Jack Arsal

Smajdalf

I cannot imagine why you need such precision for this. I guess you are doing something wrong with the RTC. It is hard to tell until you provide much more detail: How long interval? How precise?
Try DS3231. If it is not enough you need an external time source. Internet or a GPS?
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slipstick

exactly sir RTC is fail to limiting precise long time intervals what should i use to get long time intervals one more thing sir i also want to do cost analysis for this project so i need to use cheep and healthy timer
So answer the question you were asked. What time intervals and precision do you need?

You my need to change either the timer or your code or both. So far you've told us nothing about what you're currently using or how you are using it.

Steve

GolamMostafa

#7
Sep 17, 2019, 02:02 pm Last Edit: Sep 17, 2019, 02:03 pm by GolamMostafa
Hello..
i am working on a real time gestures controlled robotic arm in which i have to measure time intervals. and RTC is not accurately  count down specified time interval. and i have no idea what is wrong with this timer. Should i change my timer ? which timer should be used for this purpose.
What is your required resolution -- 1 sec or 1 ms or 1 us? DS3231RTC has 1 sec resolution.

wvmarle

Use the RTC for second resolution intervals.
Use the millis() and micros() timer functions for higher resolution intervals.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

kamelryttarn

The internal clock of the 328p isn't always accurate enough for what you want do to and as suggested DS3231RTC is a temperature compensated real time clock that has a separate pin that puts out a 32kHz square wave with a pretty good accuracy. You can connect this pin (pin 1 of the DS3231) to an input on your arduino. If you choose a hardware interrupt pin (pins 2 and 3 on the Uno R3) the microcontroller will stop with whatever it is currently doing and do what it is instructed to do when the interrupt is triggered.

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