Originally Posted By: tfabris
Do you have a Digikey part number to recommend? Would the caps need to be replaced too?

Later, much, if that's okay. I'll have to look one up, and check the datasheet for the capacitors. But the onboard ones are probably just fine regardless. The tricky bit is to find an LDO (Low Drop Out) 3.3V regulator in that "package" size (SOT-23-3 ?). For sure they exist.

Quote:
if it's necessary to keep the I2S from failing then we should do it for sure.
No, we can achieve the same effect with a bunch of resistors on all of the interconnect lines. But for your semi-dead board, this would be a simpler fix. smile

Quote:
Can you clarify your thinking as to why making the chip's voltage higher would increase its reliability?

The idea is to keep the signals coming from the Arduino "in spec" for the WT32i. Referring to the "Absolute Maximum Ratings" I posted earlier, the acceptable logic levels on inputs to the WT32i must be no higher at any time than the supply voltage plus 0.3V.

So with a 2.5V supply voltage, we have to limit the serial RX and the I2S lines all to less than 2.8V. If we ran the board with a 3.3V supply, then the I2S lines would meet the spec without anything extra required.

But of course, at 3.3V, the WT32i ends up running 32% warmer than at 2.5V. Tradeoff. The resistors are probably the way to go, but wiring up so many of them starts getting messy too.

Cheers



Edited by mlord (15/12/2017 22:08)