not/invert gate with true ground / V+

I have a radio module that I need to be put in standby before putting the arduino to sleep. I can power it on/off, and that seems to work, but it takes longer than I'd like (and more power) to do vs 'standby'.

It goes to 'standby' by going to ground, and is restored by going to V+.

The invert & nand gates I tried (and a dip package I had) didn't work -- the problem is that it seemed that it was either V+ or float -- not V+ or ground.

I have tried doing it directly off an arduino digital pin, but for some reason, it "hangs on" to the sleep mode, despite going high.

A DPST relay works as expected, but it draws more current than I'd like.

any ideas? I am stymied that it wouldn't work directly off the arduino digital pin...

There is a very good chance that I am missing something very obvious, as I've been looking at it all day...

The invert & nand gates I tried

Go on name names what was the part number?
Normally they are inverter & and gates, an inverter & nand gate would give you just an AND gate.

the problem is that it seemed that it was either V+ or float -- not V+ or ground.

Very unlikely, did it have a common ground?

I have used an APC220 and had a lot of problems with using the sleep function in that it would not wake up.
I solved the problem by decoupling the En with a .01uF capacitor.

Weedpharma

weedpharma:
I solved the problem by decoupling the En with a .01uF capacitor.

Good idea, I will try that, too…

Grumpy_Mike:
Go on name names what was the part number?
Normally they are inverter & and gates, an inverter & nand gate would give you just an AND gate.

Sorry – it wasn’t “one part” it was “I tried an invert gate” “I tried a NAND gate” Both were transistor based. I had a NAND gate in DIP package; I tried to use it so it would be “on” only when pin high & (fixed) line to V+.

I seem to have resolved it by chance, or so it seems. A diode in the mix between arduino & radio seems to have resolved it – The docs were wrong, it doesn’t require the pin to go back to low, just “not high”. So I am a bit perplexed why nothing seemed to resolve it – Because it is literally arduino-pin → diode → radio CS.