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Questions tagged [rtc]

a Real time Clock, a computer clock.

3
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1answer
42 views

Using RTC on Raspberry Pi Zero while SDA/SCL pins are occupied

I have a portable project on my Raspberry Pi Zero and I am using a i2c 0.96" OLED on the SDA/SCL pins on my Raspberry Pi. I would like to add a RTC Module to my project, but all of the tutorials I ...
0
votes
2answers
31 views

Why is my RTC DS3231 but seems DS1307?

I bought a RTC DS3231 because of the accuraty of time (2ppm, I was searching an accurate RTC). When I received it, I checked that in the encapsulating it is as well marked like DS3231. But, after ...
0
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2answers
94 views

Will adding RTC to a Pi make it more stable? [closed]

I use my Pi 3 as a desktop machine and it generally does pretty good. Occasionally I run into the issue that if I use an application, mainly Firefox and sometimes Chromium, the application will either ...
1
vote
2answers
67 views

What is the memory in the DS3232 RTC for?

I'm looking for an RTC to use with my Pi and came across the Maxim DS3231M. I also saw a similar model on Maxim's website, the DS3232M, which comes with 236 bytes of SRAM. The DS3231 seems to be a ...
0
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0answers
34 views

Disconnect RTC from systemd-timesyncd.service

I have an RPI3 with an added external RTC (Adafruit PiRTC - PCF8523). My system does not have consistent access to the internet, occasionally loses power, and is remote (in the field), so physical ...
0
votes
1answer
82 views

I2C device (DS3231 RTC) not detected

I have a small DS3231 RTC module, like the following, that I am trying to get to work with my PI 3 Model B. However it is not correctly being detected by the Pi. Connected like so (ignore cables, ...
0
votes
1answer
103 views

Periodically update DS3231 RTC with NTP

I am working on a pi hat that will cut the Pi's power in the evening when the pi isn't being used in my application. Anyways, I have a couple questions about using the DS3231 RTC. There is a uC in ...
0
votes
1answer
256 views

Sync time for all Raspberry Pi's on local network without internet

There are 5 Raspberry Pi's connected to one switch (No Internet) using LAN cables. One of the Raspberry Pi has RTC module connected and it has correct date and time. Now how can all remaining four RPi'...
1
vote
1answer
123 views

Kernel does not use RTC

I have a PiFace RTC clock that I have setup on archlinux ARM on a rpi2. I have edited /boot/config.txt to add dtparam=i2c=on dtoverlay=i2c-rtc,mcp7941x=0x6f I have added i2c-dev and i2c:mcp7941x ...
1
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0answers
59 views

Kernel panic, real time clock (possibly), UPS Pico

Have a fresh install of KivyPie, which is some months old, with updates (have done apt update/upgrade). It crashes: and the reason seems to be these two lines enable_uart=1 dtoverlay=i2c-rtc,ds1307 ...
1
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2answers
2k views

Raspberry Pi 3B+ RTC and Power ON button

I have a RTC DS3231 connected to my Raspberry Pi 3 B+. I connected it using this tutorial https://www.raspberrypi-spy.co.uk/2015/05/adding-a-ds3231-real-time-clock-to-the-raspberry-pi/ and everything ...
0
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0answers
366 views

Problem using RTC using ds3231

Trying to get an RTC to load at boot. I've enabled i2c, that works fine for other components. /etc/modules contains: snd-bcm2835 i2c-bcm2835 i2c-dev rtc-ds3231 /etc/rc.local contains: echo ...
1
vote
1answer
152 views

How to hack power bank with timer to power cycle Raspberry Pi

... without an Arduino (if possible). I am aware there are well-made solutions like the WittyPi, RTC-Arduino circuits, and some others with relay switches. If a power bank is directly connected to ...
1
vote
1answer
338 views

pigpio bitbang i2c returns random data, smbus is OK

The scripts and the results mostly speak for themselves. smbus returns good data when I use the standard I2C GPIO pins, but the pigpio bit banging I2C returns what looks like random data. What might ...
5
votes
5answers
3k views

Do I need an RTC if my Raspberry Pi is continuously connected to the Internet?

How accurate would the time on my Raspberry Pi 3 be if it is continuously connected to the Internet, but without an RTC?
1
vote
3answers
683 views

rtc DS3231 not updating system with new raspbian GNU Linux 9 stretch

Just updated to Raspbian stretch and my ds3231 will not update the system clock on reboot - i suspect that the command /sbin/hwclock -s is not working in /etc/rc.local - if I just do the update ...
1
vote
1answer
336 views

real time clock problem — why do I have endless rtc0/subsystem/rtc0/subsystem

I'm having trouble with a Pi-Zero rebooting after a varying number of hours. It's not crashing, it's rebooting, so there must be a reason for its madness. I see this in syslog minutes or hours before ...
1
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0answers
172 views

How do you change the output of sudo hwclock?

Just recieved a new RTC for my Raspberry Pi. When I use the sudo hwclock command the output looks like the following: 2018-01-08 13:06:5.441956+0100 On my other Raspberry Pi’s the output looks like:...
2
votes
1answer
1k views

Windows 10 IoT does not automatically use the Real Time Clock module to automatically update the system time

bought a brand new Raspberry Pi 3 DS3231 RTC Module and integrated to correct gpio pins as it should be. But somehow Windows 10 IOT seems not detect this module. than attempted to follow follow ...
2
votes
1answer
285 views

Why is PCF8563 not recognized on Raspberry Pi 3?

I'm using a HAT that among other things has a PCF8563 real-time clock on it (fed by a supercap when the Pi is off.) I can use i2cdetect to see the device on bus 1, but the rtc-pcf8563 module does not ...
1
vote
1answer
246 views

Available RTC modules

I know the procedure to enable an external RTC, but I just wonder which are the available supported chip (in config.txt and to use with modprobe). Where can I find such a list?
0
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1answer
1k views

rtc module in Raspbian Stretch

I'm following this guide to set up the rtc module in Raspbian Stretch. First question: after the changes described, the RPi doesn't sync anymore with the actual time from the Internet. Second ...
1
vote
0answers
74 views

rtc ds1307 module loosing time

I am trying to get the rtc i2c ds1307 module working under Raspbian Jessie. I followed these guide to let the raspberry recognize the module and set it up. Fortunately everything works great. I can ...
0
votes
0answers
43 views

Choose a boot partition based on rtc contents

We ship units which have an expected life in the field of ten to twenty years. They include an RTC with a replaceable coin cell. Most of the time the machines will be powered on, so the RTC battery is ...
1
vote
2answers
83 views

Make something happen at a specific time

I have been playing with a RPi for a little while now. I have just got a new DS3231 RTC for it, and I want to use the RPi to turn an LED on at a specific time and have its brightness adjust up every ...
1
vote
2answers
243 views

RTC drifts when rebooting

I'm working on a project where an RTC (DS3231) is needed since the RPi will not have continuous access to the internet. I've been able to set the clock on time and keep it but I've observed that a ...
2
votes
1answer
491 views

Can I use SDA0 and SCL0 for DS3231 RTC?

I want to install a Adafruit DS3231 RTC breakout on my RPI 3, the problem that I see is that the I2C pins (3->SDA1, 5->SCL1) recommended for installing are not free because I have a RazBerry Z-Wave ...
0
votes
1answer
958 views

Read and store timestamp value from hwclock (RTC)

Background: I successfully configured a DS3231 RTC to keep time and I can correctly read it with hwclock -r or hwclock -D commands. Question: How do I store timestamp value (e.g. 1500075260) into a ...
1
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0answers
92 views

how to configure mcp79410 for Raspberry pi?

I was trying to configure an MCP79410 with a Raspberry Pi using steps showed here. Each step worked well I tried the command, hwclock -w. In response, I got the error message: hwclock: Time out ...
0
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0answers
543 views

Raspberry PI3 RTC problems with ntpd on jessie

i am looking for a solution that can prefer NTP, updating the RTC when possible, and then fall back to the RTC when no network is available. it seems that NTP do this job and when the ntp is running ...
2
votes
1answer
2k views

DS3231 RTC not keeping time after shutdown on Raspberry Pi?

I'm assembling a Smart Mirror for an applied project for college. This mirror has a Raspberry Pi 3 on the back. How this all started is that the campus' network blocks NTP, so we had to buy an RTC ...
1
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0answers
101 views

RTC and high speed access to real time

Does any solution exist for RTC with following consideration? Does not have to be battery backed. The time can be set using a network clock at the OS (Linux) startup. The time needs to be accessible ...
7
votes
2answers
1k views

How to setup a MCP79410 real time clock?

I was trying to set up a MCP79410 real time clock (RTC) and had to search quite a bit until I found a way to integrate the RTC's time signal into my Raspbian Jessie: Apparently, even there, some ...
1
vote
1answer
604 views

using a real time clock (rtc) with Raspbian

The Raspberry Pi doesn't come with a realtime clock; if you want to run a standalone (no network) pi with the proper time automatically set on boot you need a real time clock (rtc). There are a ...
1
vote
1answer
181 views

How to add RTC as Clocksource on Raspberry Pi Zero running Rasbian

Is it possible to add a hardware clock to available_clocksource in order to select it as the current_clocksource found in: /sys/devices/system/clocksource/clocksource0
0
votes
1answer
699 views

How to configure Raspberry pi 3 for RTC PCF8563

I am using RTC PCF8563 module with my raspberry pi 3.I tried to configure RTC clock by using command sudo hwclock -w,but every time restart i am getting old clock time of shutdown.
2
votes
2answers
5k views

Raspberry Pi 3 + DS3231 RTC

I have done almost everything from numerous tutorials to get the RTC to work, but when I run sudo hwclock -r, i still get the following error. hwclock: Cannot access the Hardware Clock via any ...
0
votes
1answer
642 views

DS3231 RTC corruption issue @ reboot with raspberry pi3 on 2016-05-27-raspbian-jessie

I want to interface precision RTC DS3231 with Raspberry Pi3, so that my PI will get accurate time (even in the absence of network). I am using the latest raspbian image 2016-05-27-raspbian-jessie. I ...
2
votes
2answers
2k views

How to install RTC on RPi3 with Kali Linux as OS?

I am using Raspberry Pi3 B with OS: Kali Linux Kernal: 4.1.19-v7 RTC: DS3231 Real Time Clock I configured I2C manually following the instruction here. Steps I did: Install the i2c-tools utility ...
5
votes
4answers
2k views

Raspberry Pi stable date time

I'm working on a Raspberry Pi project, in which date and time are the most important factors. So, I want them to be very accurate. I know there are two methods to configure the Raspberry Pi's date ...
1
vote
0answers
79 views

Share the Raspberry Pi date and time with esp8266 on the same network

I would like to share the time and date on my Raspberry Pi, which is functioning as a MQTT server, with the ESP8266 units on my network. This is so I do not have to attach RTC boards to each one. I ...
1
vote
4answers
529 views

Where exactly are these GPIO pins located on Raspberry PI 2 Model B?

I am having hard time understanding the Raspberry PI 2 Model B's PINOUT. I have RTC Module I want to use with my PI, but no matter what I do there seems to be NO response at all from RTC. I even ...
2
votes
2answers
2k views

Why many RaspberryPi add on has pull up resistors?

I was looking at the I2C in RaspberryPi and I saw that they are pulled by 1.8K resistors(I am not talking about the ID pins). On the other hand, I got one of those RTC and they got two 222Ohm pull up ...
0
votes
2answers
5k views

Cannot perform echo command to load driver for rtc module

I've come across a few tutorials for adding an rtc module to a pi. They all include a step in which you do echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device. When I try this, I get a bash: ...
3
votes
2answers
5k views

real time clock puzzle with new rasbian jessie

I have been trying to install a RTC on my raspberry pi 2 (running Raspbian Jessie lite 2015-11-21) and I run into the following problem that puzzles me: I set the correct time on the hardware clock ...
3
votes
1answer
3k views

What is needed to get I²C working with Debian Jessie?

I have a custom system running on a Raspberry Pi B+ V1.2, based on Debian Jessie (buildroot, systemd, udev) - not Raspbian - and a custom built 3.19.3 Kernel chainloaded by U-Boot and a custom init ...
4
votes
3answers
644 views

How to display real time on a Pi

How do I give my Pi system a Real Time Clock (RTC)? Is this possible? As each time when I power off my Pi, and the next time when it boots, it displays the previous power off time. Can someone ...
8
votes
3answers
8k views

How to install Real Time Clock (RTC) on Raspbian?

I have: Raspberry Pi with 2015-05-05-raspbian-wheezy ds1307 attached (it's an Adafruit board, pullup resistors not installed). How do I: configure drivers make sure the Pi actually uses the RTC ...
2
votes
3answers
985 views

Real Time Clock Module Will it fry my pi?

I bought this RTC module on ebay for pennies. I initially bought it for the arduino but now I would like to use it with the pi. However, I know that in some cases you need logic level converters to ...
1
vote
2answers
303 views

Is there a way to connect an I2C RTC using pins 17,19,21,23,25?

I've been looking at I2C RTC modules like this one, but they all appear to be normally connected to pins 1,3,5,7,9. However, I'd also like to try to use a RaZberry Z-wave module on the same Rasberry ...