I am not completely sure where my problem is but I think I have narrowed it down to its core and it seems to be a power (stability) issue. Solving it might be a hassle but maybe you can help.
I have a 3Dtouch sensor from microchip: https://www.microchip.com/DevelopmentTools/ProductDetails/DM160225
And I also have a Wifi USB dongle from Edimax: https://www.edimax.com/edimax/merchandise/merchandise_detail/data/edimax/global/wireless_adapters_ac1200_dual-band/ew-7822ulc/
Both are connected through USB to the beaglebone, the 3Dtouch on bus 002 (the USB bus on the pins) and one on bus 001 (the micro USB OTG connection) using a micro USB to USB A female adapter.
The board is powered with a duo cell LiPo using a step down regulator from Pololu (5V, 5A) on Vin and VB and Vin-USB (pin 1-1, 1-5, 1-7).
Sensordata from the 3Dtouch gets distorted by the Wifi dongle and I suspect that interference on the power bus is the cause of it since a stronger power regulator does help somewhat in stabilizing the issue. Furthermore using a USB extension cable on the USB wifi dongle reduces the problem substantially. Such a cable on my project would aesthetically and practically not be preferred though. From the schematic of the board I see that USB1 and the micro USB are connected with a ferrite bead (FB1).
- Would it be an option to remove FB1 and power USB1 separately from the microUSB?
- Would it be possible then to power the USB bus 002 with the sensor board on pin 1-5 and 1-7 and the rest of the board including the micro USB bus 001 through V1-1 with a separate power supply (separate power regulator)?
- Should I also do something with Vbat?
And of course would that probably solve my problem? Or does someone else recognize my issue and has a better solution?
Thanks for paying attention.