I made a small bord for Edison,and there is a USB hub chip,a 2.2' TFT LCD.like this
and I also customed the system using yocto project,removed the packages I don't need. added some other packages.It looks all good,but some times I got "PMU is busy"error when starting OS,and stuck in reboot cycle.
I use OSC to check the VCC on Edison,I got this,when "PMU is busy" shows(the blue line).
I can not fix this,somebody can help me?please and thanks.
Have you noticed if there's anything specific that triggers this? Maybe a piece of code or trying to use a specific feature of the Edison. According to this thread, /thread/75839 https://communities.intel.com/thread/75839, a user had a similar issue when trying to use PWM from the MCU.
Have you tried flashing your Edison module? You can find the instructions in here: /docs/DOC-98643 https://communities.intel.com/docs/DOC-98643.
thanks for replay,I do have contral some GPIO when OS starting,but I don't think this is a problem.I just set 3 GPIOs to output model with pullup.and the OS is stuk when the terminal shows "starting wpa_supplicant service",so is the WiFi goes wrong?and if can I change the PMU setting and how?
What Vincenze is suggesting is a good idea. I hadn't considered a lack of current and we can determine if that's the case with an external power supply. Have you already tried that? That might be the reason why the boot process stops at the time of starting the wpa_supplicant.
How do you power the device? Via the USB connector?
Can you try an external power supply?
What power chip do you use? Can it negotiate more than 100mA from a USB port?