Cubecell Vext and softSerial

#1

Hi Heltec,

I’m trying to read serial data from a US-100 sensor (connected to Vext) and power it off while in low power mode.

Unfortunately something odd seems to happen when Vext is turned off and back on again. When I read data from the sensor, the first byte that comes back is garbage. This happens even after I call softSerial.flush(), and I can’t figure out why. It’s like the power cycling causes the sensor’s serial output to mess up.

I’m also using detachInterrupt to remove any interrupts before powering off Vext.

I’ve managed to find a workaround by simply reading from the sensor twice. But, I’d rather not have to do that. Any ideas?

#2

It maybe noise data by initialization of senor.

#3

Definitely possible, but I am setting delays everywhere and being careful to call softSerial.flush(). Is there anything else I should check?

#4

After refreshing, discard the data read for the first time.