Reusing e1stop for a DHT22

paralepsis

Hi all, I've hooked up a DHT22 using the expansion pins as follows:

; DHT22 (pin 1 +V, pin 2 GND, pin 4 (E2 Stop) Data)
M308 S2 P"exp.e2_stop" Y"dht22" A"AmbTemp[C]"
M308 S3 P"S2.1" Y"dhthumidity" A"AmbHumid[%]"

This works fine, but I'm not using the E1 stop and thought I would instead reuse that as it has a keyed connector and so I'm less likely to goof something. I tried this:

M308 S2 P"e1stop" Y"dht22" A"AmbTemp[C]"
M308 S3 P"S2.1" Y"dhthumidity" A"AmbHumid[%]"

That doesn't work :). I'm sure I've done something silly, like forgetting to free the e1stop pin or something, but I am not finding the answer.

Help? Thanks!

Rob

dc42

@paralepsis you haven't done anything silly, it's because ~~e2stop~~ e1stop has an input protection circuit, which prevents it being used as an output.

paralepsis

@dc42 Ah, thanks! Ok. I assume e0stop is the same, so I need to just use the e2stop approach?

dc42

@paralepsis said in Reusing e1stop for a DHT22:

@dc42 Ah, thanks! Ok. I assume e0stop is the same, so I need to just use the e2stop approach?

Correct; or you can use one of the spi.cs signals on the SPI daughter board connector.

paralepsis

@dc42 Got it, thanks again!