Hello everyone,
We are currently using an A20 Lime2 board running Debian 7 with kernel version 3.4.75. We've encountered an issue where, when setting a GPIO pin high using the Linux userspace method, the GPIO pins are only reaching 2.7 volts instead of the expected 3.3 volts. Has anyone else experienced this issue? The boards are functioning correctly otherwise, and we've observed the same behavior on multiple Lime2 boards
This is related to LDO3 and LDO4 and it was problem in some older Linux images.
If you want 3.4.xxx image, try with the official ones from here (make sure to get the latest one for your exact board):
https://ftp.olimex.com/Allwinner_Images/A20-OLinuXino/2.legacy_images_kernel_3.4.x/
If you want to test with the latest image, please test with Olimage:
https://images.olimex.com/release/a20/
Refer to this document:
https://github.com/OLIMEX/OLINUXINO/blob/master/DOCUMENTS/OLIMAGE/Olimage-guide.pdf