Orange PI PC RTC Battery or I2C RTC

RDBilbrey

I have an Orange PI PC. Can I connect a battery so the internal RTC will keep time when disconnected?
If not, can the RasClock I2C PCF2127 module be used?
I'm using OrangePI-PC_Ubuntu_Vivid_Mate.img

cbm80

I doubt Orange has any RTC, for sure not in separate chip. You would need to keep power on entire H3. Probably some DT1307 solutions from Arduino would be any chance. I hope there is kernel module for this module.

jeevasv

Allwinner H3 SoC has got a Internal RTC and a 32Khz crystal is also provided in all OPi Boards and RTC ticking correctly when power is applied. But the problem is the RTC power line is not isolated properly in order to have it ticking when power is applied. So if you apply power thru rtc pad in the PCB the RTC will keep ticking but the power consumption is way more that whatever is actually expected depleting the battery quickly. So if you power the rtc using a big battery then theoretically it is possible to keep the rtc working.

VCC_RTC Max voltage is 3.6 volt. so a 3 volt cell or 2 1.5v AA should be an easy way to power the RTC.

Otherwise it is better to use a cheap i2c RTC and update the system time while boot using startup script  or systemd unit or something.

Tina

I am looking at a 'tiny rtc i2c module' with DS1307. On it are connections: BAT, GND, VCC, SDA, SCL, DA and SQ
As far as I understand the pins can be connected to the OPI PC as follows:
OPI PC -- tiny rtc module
Pin 6 ----- GND
Pin 4 ----- VCC
Pin 3 ----- SDA
Pin 5 ----- SCL
BAT, DS and SQ normally not used.
If I would want to monitor the battery voltage, to which pin would I connect BAT?
And if I find a DS18B20 to solder on this board, where would I connect DS to?
That if the pinlayout of the OrangePI PC is 100% the same as raspberry pi 3.

dmx512

jeevasv replied at 2016-2-19 07:08
Allwinner H3 SoC has got a Internal RTC and a 32Khz crystal is also provided in all OPi Boards and R ...

@jeevasv

When checking the Orange Pi Zero schematich V1.1, there is no 32KHz crystal shown. When I do read the time register (baremetal, not Linux), then the RTC is running too fast.

Can you confirm that the internal should run fine on the Orange Pi Zero. I do not have any Linux image, so if you can make a dump of the RTC registers, that would be must appriciated.

Thanks, Arjan

dmx512

jeevasv replied at 2016-2-19 07:08
Allwinner H3 SoC has got a Internal RTC and a 32Khz crystal is also provided in all OPi Boards and R ...

Allwinner H3 SoC has got a Internal RTC and a 32Khz crystal is also provided in all OPi Boards and RTC ticking correctly when power is applied.

There seems to be no crystal, the RTC is ticking too fast -> https://forum.armbian.com/topic/ ... t&comment=95832