Hi,
i have just measured the power pins on the expansion header and can’t get the right voltage on the power pins.
The 5 V power pin just provides 3.47V and the 3.3 V just provides 2.3 V. Therefor i think this problem is the issue for controlling signals on the gpio pins ( 3.3 V mode with jumper and gpio just has 1.6 V as high signal).
The board is running and i disconnected everything excluded the power supply.
Has anyone else these problem or knows how to solve it?
Hi, please tell which pin of which connector (J21?) and what your test setup are. The 5V and 3.3V is the direct output of DC/DC, should be correct if not be impacted by other rail.
Connector is J21 and i’m just measuring the voltage of the pins in 3.3 V mode without any component connected. I measure the pin VDD_3V3_SYS and VDD_5V0_IO_SYS. FOr example also I2C_GP0_SDA_3V3_LVL just get the 2.3 V.
Can you please measure the voltage other place not on the pin of connector, as it is easy to short to other pin. If you test method has no problem, there might be some components broken.
Which one for example?
I also measured the uart and gpio expander pins with same voltage values
Might be the level shift of 1.8V to 3.3V.