I took apart old Edimax SmartPlug (model SP-1101W) to find out that the brain of the device is Ralink RT5350F chip conviniently placed on removable module board:
The board has two rows of 14 pins (28 pins total) distanced acording to raster 0.2'' :
Model description "ST&T W5350.2" text is visible but I couldn't find specification or pinout.
The bent (by me, to make some tests) pins are not connected to the main board, that looks like this:
On the main board I can see three solder/testing pads: GND, 3.3V and 12.0V and an unused row of 6-pin connector - I'd guess that that's the programmer interface, but I don't know what type.
My goal is to upload/burn custom image to the Ralink board, for example OpenWRT (in theory it should run on RT5350). I don't have enough experience to plan the entire process. I'm looking for some help:
- How to discover pin functions? Maybe someone experienced could guess something from the conventions used in board design?
- How to find UART TX and RX pins? Maybe the current Edimax software exposes something on the Serial port. I had some experience with this product and I can say that it is not well secured, so it is poosible that some software console will be available over Serial port.
- How to check if there is any bootloader allowing to upload a new image?
- How to burn new image using some low-level programmer device (what do I need?)?
