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Questions tagged [real-time-clock]

Quoting Wikipedia:

A real-time clock (RTC) is a computer clock (most often in the form of an integrated circuit) that keeps track of the current time.

Micro controllers, Android, related assembly (or low-level) code are concepts that usually accompany so make sure you pick the right one.

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read time from linux and set it to arduino RTC

I write script from openwrt to send "0" to arduino via usb serial port if arduino receive that character it will be trigger pin 8 to LOW But my problem is right now is i have RTCds1307 when linux openwrt connected to NTP it provide time to set to…
Palat Maverix Poonratchatayoth
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get time from DS1307 in Setup() and Loop()

I am implementing a DS1307 in a project using the DS1307RTC library and have 2 questions: Initialisation of the DS1307RTC happens automatically. This seems to prevent use of the library in my own library. Why is this implemented like this? and can…
Don Quichot
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PIC24F32KA302 RTC configuration

I want to configure RTC of PIC24F32KA302 so that LED toggles every second. Howerver, it does not work. Please, find attach below RTC code which I write to initialize internal RTC. IDE: MPLAB X IDE Programmer: PICKit 3 Compiler:…
uv_utna
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makes pointer from integer without a cast... DS1307, RTC, BCD

I know this question has been asked before. It's all over Google and on this site too, but I can't understand people when they explain it. I have already spent far too many hours trying to understand and I still don't so please try to understand…
Tomi Fodor
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Arduino with RTC getting the wrong year

I am working on this Arduino test application as a part of a bigger project. I have connected my Arduino to a Grove RTC (Realtime clock DS1307) module which is now spitting out date and time in my serial monitor. However the year is wrong. As seen…
RonRonDK
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Prevent compiler-generated code from clearing a location at initialization

We implemented a Real Time Clock in a PIC micro, which increments a count of seconds in RAM. If there's a reset, the C code created by the compiler will clear the RAM, and the count is lost. (That is not a problem if we use assembly instead of…
Davide Andrea
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RTC not acknowledging slave address

I'm writing a driver for m41t83 RTC IC and on AT91SAM7X (based on ARM7). I'm trying to start communication with it over TWI (fast mode) and I have no response from the RTC (always get NACK). I don't know what might cause the problem. Attached here…
Mohamed Yacout
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Arduino error compiling

I am having a compiling error with my new code. I cannot find the anything wrong. I have searched google. Any help would be great. Please see below for the code and the error message. Code: http://pastebin.com/cLprnCRz Error…
John Stilwell
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Adding support for bq32000

I have BBB running lastest debian and rtc bq32000 connected to it's I2C bus. i2cdetect shows presence of the device at valid address(0x68). I've downloaded rtc-bq32k.c driver and stuck. Can anyone point me out how to proceed further?
user2017181
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iOS Updating UITablieView rows based on time

How can I show tableviewcells based on time? Think of showing what current stores are open based on what time it is. It was suggested to me to pull real time, and NSlog the results conditionally. So how do I log tabview cells conditionally with…
newbiospro.
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in Linux, when reading an I2C-based RTC, who handles counter carry-over conditions?

When reading multiple bytes from an I2C-based RTC, it seems that it is possible that while reading each byte, one of the values may increment. For instance, if the time is: 2014-12-31 23:59:59 as you're reading this value, the time may roll-over…
Anthony Earl Wong
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Raspberry Pi problems with MySQL after i2c installation

I have a strange problem with my RPi. I'm trying to make a Weather Station on Raspbian. Here's what I did: installed Raspbian apt-get upgrade, apt-get update, rpi-update, then again upgrade and update configured i2c…
Krzysztof Buczak
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MSP430F6638 RTC_B RTCRDY bit never set

Using RTC_B XIN is connected to a 32.768 kHz clock source (not oscillator) XIN Bypass is used since no oscillator Init code is as follows: //Calendar mode, BCD coded, stop rtc, hourly interrupt RTCCTL01 = RTCTEV_0 + RTCHOLD; //no…
OneGuyInDc
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ATmega: wake up ATmega with external RTC

I'm working on a data logger which should safe as much as possible battery life. Therefore the logger (the chip ATmega 328P) is put to sleep and everything work just fine. Now I want to extend the setup with an RTC module (DS3231) to have the time…
JFS
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Arduino RTC rtc.getAlarmHour() not working

I am trying to read the alarm that is set in my Arduino real time clock (RTC), but for some reason rtc.getAlarmHour() and rtc.getAlarmMinute() don't seem to work. I had them working before, but I'm not sure what changed. I am using Arduino Uno. …
user2118142
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