开云体育

Marty,
I tried my own 3v mod to a Nano clone(see photo).? I dropped the 5v USB using 2 series 1n9148 diodes and the on board
shotkey diode.? Then routed the 5V USB voltage to the 5V Arduino pin (had to cut a trace that went to the 5V
regulator).? Then an external 3.3v AMS1117 reg for the SA parts.? Easy and cheap.? Mostly worked.? Had a problem
with the SA trace background noise stepped down from a higher level.???? Gave up and went back to 5V with level shifters.? I left the Nano at 16MHz, I think that may be a problem?? Maybe I got a marginal Nano?
Changing the regulator didn't look easy.

I don't have an external display yet, just want PC display at present.? I think SI4432s are SPI..? Erik's
code allows SPI on any pins(is bit bang).? You just need another nSel pin(any pin)? for the display (with level shift).
You could use voltage divider resistors or red LEDs (and pulldown R) instead of level shifters.

YES, this is a great project, have been following and working on for a few months.? My proto is working and better
than expectations considering no shielding, no low pass filter, marginal 433MHz filter, long wires, laptop USB
power only, etc.
I was going to get around to Farhan's Specan with estimated $100 cost (vs. $35 tinySA) and much more work with
probably worse performance and much larger unit.
I try to keep Nanos, level shifters, etc. in stock, they are so cheap I use them like I would use transistors.
Please keep us informed.
73,
Gary
WB6OGD