Hello. I got for free a little chinese router, named Cudy WR300.
2.4Ghz, three ethernet 10/100 ports, http and telnet network access.
I opened it and saw a Mediatek MT7628KN chip, which looked promising, paired with a MXIC MX 25L1606E 16MBit SPI Flash and a nice serial header to play without soldering 
So I guess it has only the RAM embedded in the Mediatek SoC, making it a (micro) 2/8MB device.
Since the SoC is fully supported by openwrt, is there any chance to build a tiny custom build and use it as a dumb AP to extend an openwrt-based network, with wired backhaul, in a thick walled house?
My only desire would be 802.11r, so -as far I know- a wpad-full is required.
Any thoughts?
With 2M flash and 8M ram there is no chance to run a linux kernel.
At least you have to solder a bigger flash chip.
Are you sure there is no additional dram chip on the pcb?
Can you post the serial log if you've soldered a pin header?
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Here it is. I see no other chip. The back is empty.
The serial header pins were already there, so I just need a cable adapter. I will try.
Q: What makes integrated RAM (or pop-on RAM) attractive for cost cutting?
A: not having to route (at least) 60 impedance- and length matched lanes (DDR2) on the PCB. This not just reduces the time to design it, but also saves the number of layers on the PCB, its size, the number of external components, etc. As a result the SOC chip can be smaller - and has less pins (well, BGA balls).
SPI-NOR flash is simple, 8 pins (and only 6 of those need to go to the SOC) - which aren't even that sensitive in terms of routing requirements. RAM is not, with 60-84 pins for DDR2 (which is still common on low-end routers). There is no need to look any further, the SOC doesn't expose the pins necessary to connect external RAM - that's its whole selling point, cheap, few bga balls, less PCB complexity and layers, smaller devices.
8 MB RAM are completely insufficient for running OpenWrt (or linux at all), even old (ancient) versions didn't support that. Therefore even the vendors don't try that, but use a different OS instead (e.g. ThreadX and similar stuff).
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I read the same in another discussion on a similar device.
OK, further investigating would be just a waste of time. Givin'up.
Thanks all.
Hope this thread could be useful for other people in search for cheap devices.
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