I want to use 40pin header.
when any peripheral is connected, I find that the 5V voltage is pulled down and the peripheral can’t start running. The voltage changes from 5V to 2.2V. my device does not have any high power devices, only two stm32 chips or 1 nrf51822 chip.
Therefore, I don’t use jetson-NX for power supply.Instead, I connect SPI-SCK,SPI-MOSI,GND directly to my peripheral. But I also found that the spi-sck and spi-mosi voltages are also pulled down.
I have already configured the SPI using the jetson-IO tool. When the spi pins of jetson-NX are not connected to any device, they are 0V-3.3V. Once another device is connected, the voltage of spi-sck becomes 0-1.5V or 0-2V
Thank you very much, according to your suggestion, I have successfully solved the problem of SPI voltage, but there is still a problem left above. I tested all the 5V and 3.3V voltages, only 3.3V is normally powered, but the 5V connected device immediately dropped to 2.2V