more notes

notes/DIU-Apple-Notes.md

@@ -64,3 +64,5 @@ References
 * [NOYITO 8V-22V to 3.3V 2A Buck Converter](amazon.com/NOYITO-Waterproof-Overcurrent-Short-Circuit-Undervoltage/dp/B07HCTNHL7/)
 * [KNACRO 8V-22V to 3.3V 3A Buck Converter](amazon.com/KNACRO-Synchronous-Over-temperature-over-current-protection/dp/B07B8CRXK6/)
 * [SCI16IS740/750/760](https://www.nxp.com/docs/en/data-sheet/SC16IS740_750_760.pdf) UART with I2c/SPI interface
+* [ADS1015 12 bit ADC](https://www.adafruit.com/product/1083)
+* [4N25S-TA1 Optoisolator](https://www.digikey.com/product-detail/en/lite-on-inc/4N25S-TA1/160-1910-1-ND/3711405)

notes/Sensing-Notes.md

@@ -0,0 +1,10 @@
+Sensing Notes
+===
+
+Ideally, there would be sensors on the board to sense both input voltage from
+the bus, regulated voltage, temperature, pressure, heading, acceleration, etc.
+
+References
+---
+
+* [An isolated analog input for Arduino ](http://ardupiclab.blogspot.com/2016/05/an-isolated-analog-input-for-arduino-by.html)