Add-ons
How to add battery to keep rtc time
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[Add-ons]
How to add battery to keep rtc time
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For testing I'm using ntp during bootup... But it seems the board is ready for RTC, except battery itself and IF theres no mistakes in wiring (Crystal, Battery).
And it seems all that is left to do is simple apply this patch as it is: https://groups.google.com/forum/ ... ev23iM/0tJtY45S0B4J |
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Hey 
On the board is place no for standard battery, but for GOLD AP (vel Super CAP). This is special huge 0,047F 3.3V Capacitor. |
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sylwek2k, are you sure? At least without schematics or A20 desoldering it will be hard to define... And that capacitor (to do what intended) should be connected to VRM output - but it is not... |
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Reply 13# Ra
Schematic specialy 4U:
http://www.allnet.de/bananapi/downloads/A20_Blockdiagramm_BananaPI.pdf
;) |
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Thanks a lot, sylwek2k! Yes, now I see, that it should be 0,047F 3.3V Capacitor. All is correct. I'll give it a try - will run board with 3V CRXXXX battery, if Sunxi RTC kernel module is there - seems, will work. |
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many thanks sylwek2k and Ra ! |
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Well you may use an i2c rtc Addon Chip (2-5€), this Ines came usually with an backupbattery. The only Thinge to to is to get the realtime from i2c decive And put the Time to systemclock. |
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I'm using a RTC add-on board for RPi. It comprises an NXP PCF2129 and CR2032 battery holder. It works very well on my Banana Pi. |
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Reply 19# HWL_Stouf
You don't necessarily need a driver. My RTC board comes with a program that reads the RTC and sets the system clock when Linux starts up and then once every day. It's added to the crontab of the root user. |
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