My apologies if this answer is in the forum somewhere. I've honestly searched and can't come across anything.
I'm planning to use an ATTiny85 to do an analog read of a sensor. I'm looking for improved precision over the internal references, so I'm planning to use an external 4.096V precision voltage reference (TI REF3140).
Since Vref pin and MOSI use a common pin (pin 5), is it possible to have an external voltage reference connected to this pin and still be able to use the ISP to program the ATTiny?
- Will the 5V programming signal damage the output of the 4.096V reference?
- Will the 4.096V reference voltage block communication on the MOSI pin during programming?
- When programming, would the output of the reference voltage ever be shorted to ground?
Thanks in advance!