Hi Trevor
Forgot about this bit

Trevor277988:

I did wonder about only supplying the op-amp with 3.3, rather than 4.5V as I do now, but that is getting rather close to their minimum (3V). The upside of course is, I would never have to worry about pushing higher voltage to the GPIO.

That is one way of doing it but you would be affecting all OpAmps in th...

Hi Guys, Caio Bueno from Sumaré-SP-Brazil.

I bought two SN30 2.4G model 81AF controllers to use on the Super Nintendo and I accidentally installed the firmware “SN30 2.4G Nt (SN30_Fw_V1_23_81AD_For_Analogue.dat)” on one of them, and now this controller is no longer working with the receiver (the receiver has no update ports). Could you advise me on the correct firmware...

Hi Trevor

Trevor277988:

But the output from my op-amp (when it goes high, ie pump turns on) will (for now) be close to 4.5 V… so that might explain it.

When the output goes to 4.5V then the diode SHOULD conduct and clamp the GPIO pin to the 3V3 rail. But when the goes LOW GPIO15 should go LOW with it as the diode will then be OFF. I don’t have any idea wh...

Thanks Bob. Maybe I’ll replace that diode, see if changes anything.

But the output from my op-amp (when it goes high, ie pump turns on) will (for now) be close to 4.5 V… so that might explain it.

I did wonder about only supplying the op-amp with 3.3, rather than 4.5V as I do now, but that is getting rather close to their minimum (3V). The upside of course is, I ...

Hi Trevor
That BAT85 behaviour seems crazy. It should not turn on and thus clamp until the voltage on GPIO15 rises to about 3.6V or so. Until then it should be off thus isolating GPIO15. There is something not right. Perhaps a very leaky diode. Don’t know.

Quick fix Forget the BAT85 and connect a 3V3 zener to GPIO15, cathode to GPIO15 and anode to ground. You can i...