Can a CMOS battery and circuit be installed?

Everything relating to hacking, expanding and modifying the Joggler hardware.
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pete
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Can a CMOS battery and circuit be installed?

Post by pete »

Just curious if I could install a 3.3VDC cmos battery circuit to clock chip (9UMS9001) and SST49LF008A on the Joggler.

I am just wondering and do not know anything about doing stuff like this; if done would this keep the time on a cold reboot?
- Pete
O2 Jogglers running EFI Ubuntu / Squeezeplayer
OpenPeak Voip Telephony / Zigbee tabletops hardware modded with Seabios / RTC / Ethernet ROM edits / SSD drives running XPe for automation screens

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demir
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Re: Can a CMOS battery and circuit be installed?

Post by demir »

I think that there should be no problem on doing this. It has been a long time since you posted this question, did you try it out? Did it work?
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pete
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Re: Can a CMOS battery and circuit be installed?

Post by pete »

I never did.

I haven't looked at the insides of the O2 Jogglers in a while now. They are just doing their thing now.

That said all of the Openframe 2 models from what I can see have little CMOS batteries in them next to the flash boot chip.
- Pete
O2 Jogglers running EFI Ubuntu / Squeezeplayer
OpenPeak Voip Telephony / Zigbee tabletops hardware modded with Seabios / RTC / Ethernet ROM edits / SSD drives running XPe for automation screens

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Juggler
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Re: Can a CMOS battery and circuit be installed?

Post by Juggler »

This would be a really useful modification.

This wouldn't improve the accuracy of the Jogglers clock, would it ? Or are you thinking of having a separate clock, keeping this alive with the battery, and updating the Joggler's clock periodically from this ?

I've noticed from the Jogglers I have running 24/7 for some months now, that they gain about 1 second a day, if not corrected. I don't have them on a network permanently, but have used some ethernet over power-line adaptors to update system time from NTP and do other maintenance on them. These are really useful adaptors and can be just used when needed. The price of the lower speed version (200MB/s) is now at a reasonable amount (recently bought a pair for £15).
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pete
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Re: Can a CMOS battery and circuit be installed?

Post by pete »

Just glanced over at a taken apart Joggler III.

The battery is next to the flash chip.

The board has many similiarities to the O2 Joggler and Joggler II. I will try to trace where the battery leads go. I do see one diode in the path out plus what appears to be a small voltage regulator.

I moved many of the Jogglers over to the TP-Link POE adapters (old and new now). These are connecting to 4 different POE switches today. My favorite one is a Tycon midstream POE switch (managed).

Just noticed that TP-Link now makes a Gb POE injector. I have been using the first two models on the right of the attached link. (a few over a year now 24/7).
I currently sync NTP internally with an NTP server connected to a GPS. I have adjusted the O2 OS Jogglers and Linux (whatever running) to point first to the on the lan NTP server. The wintel Jogglers utilize Tardis for time sync today.
- Pete
O2 Jogglers running EFI Ubuntu / Squeezeplayer
OpenPeak Voip Telephony / Zigbee tabletops hardware modded with Seabios / RTC / Ethernet ROM edits / SSD drives running XPe for automation screens

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pete
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Joined: Mon Aug 01, 2011 6:33 am
Location: Time Traveler

Re: Can a CMOS battery and circuit be installed?

Post by pete »

Thinking about trying / using a battery clock from an ardino.

References:

http://www.sunspot.co.uk/Projects/Joggler/i2c.html

http://www.freetronics.com/pages/rtc-re ... opF0ifRbf0
VCC: Connect the 5V or 3.3V from your Arduino or circuit here to power the module
GND: Connect this to your Arduino or board’s GND pin
SDA: This is the I2C bus data pin, connect to your Arduino’s A4 pin
SCL: This is the I2C bus clock pin, connect to your Arduino’s A5 pin
32K: The module has a 32 kHz square wave output from this pin
BAT: You can connect the ‘+’ of an external backup battery to this point
SQI: From this pin comes the controllable square-wave.
RST: At this stage it’s unused, it can be used as a part of a reset switch.
rtc_bottom_yellow_medium.png
rtc_bottom_yellow_medium.png (55.91 KiB) Viewed 4975 times
- Pete
O2 Jogglers running EFI Ubuntu / Squeezeplayer
OpenPeak Voip Telephony / Zigbee tabletops hardware modded with Seabios / RTC / Ethernet ROM edits / SSD drives running XPe for automation screens

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