Hello, I'm using an LPC2368. The RTC is supplied by a battery. Is there a possability to check the battery voltage to generate an error for the customer? I don't want measure by AD Converter. Do you have a solution how can I do this with software? thanks
The processor can't measure the battery. So you just need to connect the battery to an ADC - and having a FET that allows you to just connect the ADC when measuring, to avoid extra drain of the battery between measurements.
Note that the LPC23xx chips are a bit hungry, in some cases stealing quite a lot of current from that RTC battery. See for example the chip errata.
thank you