WP34s Differential Time and shift

[matthiaspaul]

(02-11-2015 09:07 PM)matthiaspaul Wrote:  Since the firmware already includes code for the analog/digital conversion of the battery voltage

I meanwhile had a look at the sources and have to correct myself. The code to detect the battery voltage does not use one of the four free ADC inputs, but the internal brown-out detection logic. One of the advantages of this approach is that no external voltage divider is needed, so less energy is wasted (the reference voltage for the ADCs is clamped to 1.8V).

However, this means that there is no particular advantage of using an analog temperature sensor over other types of sensors. The eight spare I/O pins include the signals necessary for SPI. An I2C interface would be available in parallel to the ON key (and would therefore be difficult to use).

Greetings,

Matthias