ZipIt RTC

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Alternatively you can add an I2C port to the exterior of your ZipIt for adding expansion modules without opening the case again. See ZipIt I2C.

Parts

DS1338C-33 - Dallas Semi. RTC w/ 56byte NVRAM & Internal Crystal 3.3v

Howto

In order to add a RTC to your zipit you have to do some very delicate soldering. If you don't have a ultrafine tip iron, and a few years soldering experience - do NOT attempt this. You will be soldering wires directly to the LPC915, if this chip is damaged your zipit will not boot.

Under Construction

Wiring overview

Overview.jpg

Connections to Power

You have two choices for battery backup of the RTC, running off the ZipIt's rechargable (bad idea, clock isnt happy with the full range of the battery), or adding a coin battery just for the clock. Originally I attempted to run the clock backup feed off the ZipIt battery only to have trouble with the clock dumping randomly. I now use a 3.3V coin cell harvested from a dead Playstation2 with no problems.

Powerconnections.jpg

Details of connections to I2C

I2c.jpg