Measuring MISO pin voltage on ESP32 reads 0.01V

[mrimskiy]

Hi,

I am using the ADNS3080 optical flow sensor on the ESP32 microcontroller. I read that the MISO of the sensor needed 3.3V, but I measure 0.01V on the ESP32 MISO pin. Is this normal?

MrImskiy

[hammy]

Yes , that pin normally sits at 0v and pulses during coms , have a look

Here

[DrDiettrich]

@mrimskiy

I measure 0.01V on the ESP32 MISO pin.

The voltage can be anything as long as no slave is selected. I found no spec of a possible pulldown on the MISO line.

[awneil]

@mrimskiy

I read that the MISO of the sensor needed 3.3V

Where did you read that? Please give a link.

I suspect that you are misinterpreting it; it probably just means that 3.3V is the maximum that's allowed on that pin - so 0V represent logic '0' and 3.3V represents logic '1'.

Also:

MISO = Master-In, Slave-Out:
The sensor is the slave, so its specification of MISO would tell you what the slave generates - not what it "needs"