Does rock64 have a RTC

[jata]

Hi all,

I was checking the logs on my rock64 - purchased in Feb 2018 and I see entries that look like there is a real time clock (RTC) on the board

May 31 09:03:04 rock64 kernel: [    2.263456] rk808-rtc rk808-rtc: rtc core: registered rk808-rtc as rtc0
May 31 09:03:04 rock64 kernel: [    3.225131] rk808-rtc rk808-rtc: setting system clock to 2016-01-21 08:50:11 UTC (1453366211)

Is this correct / possible?

[Rocklobster]

Not so far but this could possibly be what you are seeing http://manpages.ubuntu.com/manpages/bion...ock.8.html

[jata]

thanks for this but this appears to be proper RTC hardware not the software that does a similar function. I'm going to keep investigating.

[pfeerick]

thanks for this but this appears to be proper RTC hardware not the software that does a similar function. I'm going to keep investigating.

The main processor (RK3328) does not have a RTC as far as I can tell, but the RK805, which is the programmable DC-DC converter unit providing all the voltages the board needs does have one. I don't know if you can use it as an RTC for the board, or if it's primary purpose of existing is just to allow for time triggered poweron. The datasheet does list all the registers and such, so if you can poke the RK805 registers you might be able to find out. Just be careful what you poke as if you poke the wrong think you might fry something by setting a voltage you shouldn't. You have been warned™ ™.

[Z80]

Yes, the RK805, definitely has the capability to provide a system RTC.

To do this they would have had to add a 32.768kHz crystal and a RTC battery connection header (about 25 cents worth of parts) but it seems that they didn't bother.

This was REALLY DUMB, but not much can be done until they re-spin the board.

For what it's worth, the ASUS Tinker Board did identically the same REALLY DUMB thing, which was even more disappointing (to me at least), because ASUS knows how to build motherboards, but seems to have forgotten EVERYTHING they ever learned in their mad rush to "me too" the Raspberry Pi.

The problem with ALL these SBC makers, is they like to play follow the leader with the Raspberry Pi, which is actually a pretty crappy design, which has NONE of the basic amenities we expect on even the lowest cost small PC motherboards.  No power switch header, no power and drive activity LED headers (needed to connect external case switches and LEDs), no capability for a REAL hard drive like a SATA or M.2 drive - and of course NO REAL TIME CLOCK.

Some of the Banana Pis can do SATA, while a couple of the Hardkernel boards do have RTCs on board, but so far as I can tell no one checks all the boxes.

A board the size of the Rock64 with all the standard motherboard connection and control headers I mention above, plus a PC style onboard RTC, and M.2 socket for a high performance SSD, and 4Gigs of onboard RAM would be a killer product, especially with one of the new faster Rockchip or Amlogic CPUs.

Just my 2 cents worth...

[pfeerick]

Yes, the RK805, definitely has the capability to provide a system RTC.

To do this they would have had to add a 32.768kHz crystal and a RTC battery connection header (about 25 cents worth of parts) but it seems that they didn't bother.

This was REALLY DUMB, but not much can be done until they re-spin the board.

For what it's worth, the ASUS Tinker Board did identically the same REALLY DUMB thing, which was even more disappointing (to me at least), because ASUS knows how to build motherboards, but seems to have forgotten EVERYTHING they ever learned in their mad rush to "me too" the Raspberry Pi.

The problem with ALL these SBC makers, is they like to play follow the leader with the Raspberry Pi, which is actually a pretty crappy design, which has NONE of the basic amenities we expect on even the lowest cost small PC motherboards.  No power switch header, no power and drive activity LED headers (needed to connect external case switches and LEDs), no capability for a REAL hard drive like a SATA or M.2 drive - and of course NO REAL TIME CLOCK.

Some of the Banana Pis can do SATA, while a couple of the Hardkernel boards do have RTCs on board, but so far as I can tell no one checks all the boxes.

A board the size of the Rock64 with all the standard motherboard connection and control headers I mention above, plus a PC style onboard RTC, and M.2 socket for a high performance SSD, and 4Gigs of onboard RAM would be a killer product, especially with one of the new faster Rockchip or Amlogic CPUs.

Just my 2 cents worth...

Just 2 cents? Thought that was a whole dollars worth! :-P

Yeah, I actually think the pine64 was nearer to a fully featured board. It had RTC backup, lipo battery support and management, a fully rPi header and the extra euler bus, as well as integrated LCD and touch support. The new rockpro64 might be the nearest to the PC world... much beefier CPU, 4GB RAM, USB3 and GbE, miniPCI for SATA drives, rPi header, onboard leds, eMMC, SPI FLASH (so PXE and USB boot will also be options) plus one of the sockets is marked RTC. So getting warmer

Although I'm not sure what the fuss is about for a RTC on a SBC... what's wrong with the network time? Or just adding your own I2C RTC if you really need it (like we used to do with the rPi? :-P Gotta have some ingenuity... can't have it all served up to you on a platter... where's the fun in that? :-P

[evilbunny]

Although I'm not sure what the fuss is about for a RTC on a SBC... what's wrong with the network time? Or just adding your own I2C RTC if you really need it (like we used to do with the rPi? :-P Gotta have some ingenuity... can't have it all served up to you on a platter... where's the fun in that? :-P

One real world example I have is my r64 is hooked up to a weather station. Software then tries to download missing records while the r64 was offline, this occurs before network or ntp is up and running, this can be delayed. My solution was to hook up a car battery to a UPS, but RTC would have been nicer.

[Z80]

Although I'm not sure what the fuss is about for a RTC on a SBC... what's wrong with the network time? Or just adding your own I2C RTC if you really need it (like we used to do with the rPi? :-P Gotta have some ingenuity... can't have it all served up to you on a platter... where's the fun in that? :-P

One real world example I have is my r64 is hooked up to a weather station. Software then tries to download missing records while the r64 was offline, this occurs before network or ntp is up and running, this can be delayed, but my solution was to hook up a car battery to a UPS, but RTC would have been nicer.

Exactly, SBC's are often used in portable devices that need accurate time keeping when not connected to the network.

On my Raspberry Pi's I use one of those little coin cell driven DS3231 boards, but found it a pain to always have to install drivers.  Now I think the Pi does have RTC kernel driver support that can be activated in boot config, but have always just used the script I wrote. 

This highlights what I consider the bigest advantage of built in RTC support - STANDARD BUILT IN DRIVERS.

One thing I do like about the DS3231 based boards is that they are MUCH more accurate than typical simple 32.768kHz crystal based RTCs because they are temperature compensated.  You can run them for months and still keep time accurate to a few seconds per month, but if someone needs that kind of unattended accuracy, they can easily add one of these add-on modules as pfeerick said - BUT THEY SHOULDN'T BE FORCED TO DO THIS JUST TO GET BASIC RTC FUNCTIONALITY.

The simple built in RTC clocks provided by these ARM chipsets are good enough for most folks, and will also keep great time if  auto synced to Internet time every few weeks, and I find it offensive as an engineer that the end user should be forced to pay 5 to 10 dollars for an add-on module, and deal with custom drivers, just because the person who designed the board was too cheap to spend 25 cents to add the parts necessary to make the on-board RTC functional.

[jata]

Hi all,

So I am trying to get a DS3231 working on my rock64 but I can't work out where on the GPIO it needs to sit. where is the correct location?

I have established that the RTC on the rock64 is quite useless as it does not have a battery so it does not keep time when you disconnect the power...

[fire219]

Hi all,

So I am trying to get a DS3231 working on my rock64 but I can't work out where on the GPIO it needs to sit. where is the correct location?

I have established that the RTC on the rock64 is quite useless as it does not have a battery so it does not keep time when you disconnect the power...

The large pin header on the R64 is fully Raspberry Pi compatible, therefore a guide for how to add a DS3231 to a RPi should give you all the information you need.