To make a voltmeter wouldn't be so diffucult, every modern microcontroller has a built in ADC which has a good enough precision.
But if you speak about the handheld vaping machines, space will be your issue. Also be aware that lithium batteries don't have a linear curve discharge. The fully charged litium batteries (eg.18650 model) will have 4.2v, then rapidly drop to 3.7v, then it will rather slowly drop to 3.3v (like from 95% to 10%) after that, the smart cells switch off (0V) to prevent damage, not smart cells will then drop rapidly to 2.7-something V http://img.photobucket.com/albums/v137/Tweek_CPF/18650_2400mAh.jpg So using the voltmeter as charge indicator might be not the best idea. If i would do a voltmeter i would possibly use a Attiny and discrete transistors to control the cathodes of the nixies, and of course multiplex them. The attiny could measure the voltage too, and a pwm pin could be used for hv generating (yes, inefficient) -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/f7a7b3c3-a40f-4654-85bf-64efa5ecba4d%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
