Digital IO Inverted
Posted: Fri Jun 26, 2020 7:14 pm
Hi all
I've had a RedPitaya v1.1 in my drawer for a couple years, and recently dusted it off, upgraded to the current FW (details as reported in the bottom right of the main screen are "Red Pitaya OS 0.98-694 / STEM 14") to do some SPI debugging using the GPIO interface. For some reason, the logic signals are all inverted in the Logic Analyser app. I feel like I'm going insane, but I've checked it from all angles, and cannot see what I'm doing wrong.
As a test, I've set up a simple flashing signal from an STM32 Discovery board 100ms on, 200ms off. When measure with the oscilloscope, the signal is as I expect to see it. However, when I have connected the GND to E1:pin 25 and the flashing signal to E1:pin 3, the logic analyser shows the signal as high when at 0V, and low when the signal is 3.3V. Am I going mad?
Thanks
Etienne
I've had a RedPitaya v1.1 in my drawer for a couple years, and recently dusted it off, upgraded to the current FW (details as reported in the bottom right of the main screen are "Red Pitaya OS 0.98-694 / STEM 14") to do some SPI debugging using the GPIO interface. For some reason, the logic signals are all inverted in the Logic Analyser app. I feel like I'm going insane, but I've checked it from all angles, and cannot see what I'm doing wrong.
As a test, I've set up a simple flashing signal from an STM32 Discovery board 100ms on, 200ms off. When measure with the oscilloscope, the signal is as I expect to see it. However, when I have connected the GND to E1:pin 25 and the flashing signal to E1:pin 3, the logic analyser shows the signal as high when at 0V, and low when the signal is 3.3V. Am I going mad?
Thanks
Etienne