Omega2S+ keeps rebooting
After developing a device on Omega2+, I created custom board for Omega2S+. Beside Omega2S+, the board has SD card, W25N01GVZEIG (NAND where CS1 is used for Chip Select), and FM24CL64B-G (F-RAM chip connected over I2C. In prototype phase, I didn't have W25N01GVZEIG so I never connected it to Omega2+ but designed the connection on the custom board.
The problem I am experiencing with Omega2S+ is constant rebooting after showing
[ 32.937566] 1. Phy Mode = 14
on UART0 while Omega2+ shows that three times. (find enclosed putty session captured on UART0 of Omega2S+. I had to rename it to .bin while I was unable to upload it but is plain text file)0_1572563211273_onionlog.bin
Also, I was able to activate console and input df -h that shows:
no /dev/mtdblock6 mounted to /overlay
and overlayfs:/tmp/root mounted to / with size of 61.0M
What might be wrong? The added NAND flash or is something wrong with internal flash that might be possible to fix with fresh image flashing from bootloader?
Many thanks for your help.
@morfeus Your power supply is not able to provide enough current (and/or appropriate voltage) for your board.
Hm, can reason for that be a IRLML6402 that is inserted in power path to be able to power off the board with external signal? Actual voltage measured on Vin of Omega is 3.06V.
@morfeus I know almost nothing about your custom board - so it's hard to guess what can be wrong on it.
BTW this is an evergreen topic on our forum and I think my guess is quite good.
When Omega2 turn on the WiFi radio your power supply is not able to provide enough peak current so your Omega2 will reboot.
mosfet is connected source to external 3.3V and drain to the board: as to be able to cut the power using gate signal (pulling gate high).
Based on your "hint" I powered up the board from laboratory power supply and set voltage 3.6V. Onion now works as expected. So definitely voltage drop across mosfet is more than 0.3V and that way, Onion Vdd get down to minimum allowed 2.97V causing an reset (and reboot: because voltage "recovers" to acceptable level).
Thanks for your help.