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Topic: temperature compensation crystal oscillator (Read 6945 times) previous topic - next topic

bigbuck83

I have noticed the battery in the chronodot wants to try and power the arduino when the arduino is powered  off I guess adding the 2 pull up resistors will correct this issue

Jack Christensen


I have noticed the battery in the chronodot wants to try and power the arduino when the arduino is powered  off I guess adding the 2 pull up resistors will correct this issue


That should not happen. What are the symptoms? The battery power is separate from the main supply. How do you have it wired?
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

Jack Christensen

FYI connect the Chronodot as follows: GND to Arduino GND, Vcc to Arduino +5V, SDA to A4, SCL to A5. Leave the Chronodot BAT pin unconnected.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

bigbuck83

Yea that's it I had the 3.3v pin connected to the BAT on the chronodot and I was getting back feed when the arduino was off......... other than that it is working without changing anything

Jack Christensen

I'd make sure the coin cell in the Chronodot looks OK, not swollen or leaking, etc. The 3.3V pin was probably forcing current into it, those aren't rechargeable cells...
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

bigbuck83

ok I just changed the cell it looked ok but I changed it anyway............. the chronodot is working very well and the previous issue was resolved

bigbuck83

Hello,
I was wondering If I can control 2 arduino uno  with one chronodot.... I have tried this and it works but I am not sure if it is ok to do

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