Difficulties with setting up external LEDs with provided pins

Youyeetoo X1 SBC(X64)
1

I’m trying to connect external LEDs and a power switch to the LED/Pwr switch header but have not been able to get this to work properly. I have already discovered that the pins are numbered backwards from JST standard, so that’s not my problem (and I have the external power button working fine).

When I connect an LED across LED+ to LED1-, there is not enough voltage to light up the LED. There is only 1.7 volts between LED+ and LED1-, which is not enough to activate a normal LED. The same problem happens with LED2- which is only 1.9 V.

I have also measured LED+ vs Ground which is only 2.5 V instead of 3.3 V as indicated in the schematic I found elsewhere in this forum.

If I’m understanding the schematic, it seems like the drop-down voltage of the built-in LEDs is going to limit how this could ever work because that is what limits the voltage between LED+ and LED1- and the external LED is wired in parallel with the built-in LED. The current will only go through whichever LED has the lowest drop-down voltage.

Have I misunderstood how this is intended to work? What is the right way to wire an external LED to the connector in order to have it light up with LED1? Any help would be appreciated.

2

Perhaps your BIOS version is 1.8V.
You can try to switch the voltage of the GPIO through our tool.

At the same time, you need to check the electrical parameters of the LED to see if other voltages are required for power supply.

3

My BIOS says it is version Y_FIVE_NO_MIPI_01 0.03 x64 with a build date-time of 06/19/24 17:40:29. It does not look like any of the BIOS names in the “enter BIOS” link you provided (they all start with X1 and end with a voltage). From my BIOS version and build date, can you tell which one it is and if it is 3.3V or 1.8V?

Also, in the description for the downloadable BIOS files, it only mentions that it controls the voltages for I2C,GPIO,UART,SPI connectors. Can you clarify it if also controls voltages for the LED/Pwr connector?

Thank you.