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61 Threads found on External Rtc
Hi, It's not clear to me: is the rtc hardware or software? An rtc needs a clock. What clock source do you use? If it is an external hardware rtc with it's own xtal, then we need to see the PCB layout. Klaus
Even if you are able to determine the need to calibrate the Clock by adding/subtracting a certain amount of seconds per day, it is not accurate. There could remain fractions of a second which were not accounted on that automatic correction. If you want to have an accurate value, you should consider using external signal sources to periodically sync
Hello, I am using a PIC32 uC and on board space is critical. I have created a timer Interupt routine which constantly increments an extern variable. The count this variable holds is the number of 4 ms time slices. Therefore I am able to count the time slices and decern seconds, minutes, hours etc... My question is, I now need to make a cal
Hi, After power loss the date and time is lost. Therefore i use external rtc with backup battery. ****** Internal rtc: Isr for a fixed isr frequency. First counter for parts of second (depends on isr frequency) Then counter 0...59 for seconds (on every counter reset) Then counter 0..59 for minutes(on every second counter reset) Then (...)
Hi, I am using ATXMEGA16E5 in an application. And i use the rtc clock ( period 1 sec , external 32.768 clock) to wakeup from power save mode. After wake up i measure some ADC channels and after goes to power save mode. The program works well when no debugging. When i use the AtmelICE and i push HALT it does not stops, and IAR gives a error "
Looking at your schematic I presume that the power supply to the rtc is 5v and the backup is 3v (not 12 as shown)? You don't need external load capacitors but you have to make sure that the load capacitance of your crystal is 12.5pF - what is the load of your crystal. Where did you get your crystal from, those on E-bay are low quality and have qui
I was going through datasheet of pic micro-controller (PIC32MX795F512L) ans was wondering what the requirement of ppm for main clock (main clock i meant because there is also rtc crystal) was?? :bang: I have gone through few pic micro datasheets and found that none of them mention the ppm requirement for external crystal. Does anyone based on
Hai every one, I am using the internal rtc for my project to read the date and time, but some one said that external rtc has more advantages compared with the internal rtc why? what is the reason for that? please explain me what are the main difference between internal rtc and external (...)
The ceramic "supercap" is quite nice. But even with very low current consumption of the Abracon rtc, it will provide backup only for a few days. That may be too short for many applications. The Abracon rtc doesn't recharge the capacitor, you need an external low leakage diode.
Hi, Apart from the fact that the 16f84 is virtually obselete, a lot of basic differences, just compare the two datasheets. In respect of a "timer" is hard to say as that can cover such a wide range of possibilities; are you talking of a nano seconds timer or days and months ? Are you wanting to use an external rtc clock like the DS1307 wh
Can you wrap this as code rather then text? Some more information: 1.) Circuit setup 2.) Interrupt setup (I see that is called but I don't see where you do this at) 3.) Address definitions Hi..greg Here is my ISR and Address definitions... void rtcINTInit(void) { PORTSetPinsD
Hi, I am using a SoC which goes into sleep mode for 5 minutes. Now after 5 minutes I need to wake it up using some external trigger. What are the different ways I can implement interrupt generator in hardware? I can not use timers of SoC, as SoC is in sleep and Timers are not operational in sleep mode. I thought of rtc, counters or RC networ
Integrated: Means in built crystal. Which is best option because external crystal increase cost, space. Use it if possible plz share it's part no.For more details u can refer following link also :
PIC12F1822 have 256bytes EEPROM size, to store more data you need external EEPROM IC. You can use I2C/SPI protocol for this. One question you need real time to say when motor is off like 13:40:07-14:02:34 ? In that case you need to use rtc IC. How long you need to log this few hours, one day, week, month, ... ? You need to determine needed si
Hi guys, My problems is the lack of information in "GE864-GPS Hardware User Guide". In the section about GPS_WAKEUP and GPS_ON_OFF signals they say : The GPS starts after asserting a rising edge pulse on GPS_ON_OFF input and when high level persists for at least three cycles of rtc clock. Before asserting another pulse to GPS_ON_OFF
For voltage sensing, you can use a voltage divider and sense the voltage using the PIC ADC module. For date and time, you can use a rtc chip and interface it to PIC16F877A. You can use DS1307 and interface it to PIC16F877A using I2C protocol. You may save the data on the PIC EEPROM or you may use an external memory for larger storage space, eg an
I somewhat agree, however the cost of implementing an external rtc controller would be more than implementing a battery backup on the PIC's power supply. It would be nice to have the option of just connecting a battery though, with built-in switch over on main power loss. (Are you listening, Microchip?)
The ds1307 uses an external crystal. I think that the accuracy depends more on the crystal and related components that you use rather than the chip. Using the right crystal with good ppm deviation will improve the accuracy. See the DS were it says: Note: For more information on crystal selection and crystal layout considerations, r
If you using the Hi-Tech PICC18 compiler why not use the provided I2C libraries? Example accessing external I2C Serial EEPROM: // will automatically include peripheral library header files #include unsigned char arraywr = {1,2,3,4,5,6,7,8,0}; unsigned char arrayrd; //***************************************************
/***************************************************** Project : rtc Version : V1 Date : 5/17/2012 Author : Swaminathan Balagangatharan Company : PARC Comments: Chip type : ATmega16 Program type : Application Clock frequency : 11.059200 MHz Memory model : Small external RAM size : 0 Data Sta