RT5350F-OLinuXino development started loooooong time ago, we made the hardware very quickly and hit the wall with the software :)
The Hardware had two revisions, we knew that this IC is overheating and need external DCDC power regulator to release it from the heat, but we first decided to try how bad is it with the chip steps down the 5V to 1.2V with internal LDO, well…. the chip was easily rising to 60C at room temperature 20C, so we made revision.B where we add external DCDC and the temperature of the chip cool down to 40C, so far so good.
The next obstracle was WIFI tuning, Ralink have bunch of registers which are not described in the ‘datasheet’ but you have to know what do with them if you want to tune your WIFI to work correctly.
OpenWRT wisely skips this area of memory as each module vendor is responsible to write the optimal info for the chip in these. It took us about year to figure out what to write in these registers, including obtaining NDA info about the chip features.
The result is good, the chip makes link from up to 20 meters when in house and up to 50-60 meters in open air which is about the maximum of this small PCB printed antenna.
RT5350F-OLinuXino is now in stock and cost EUR 15 in single quantity.
We didn’t stop here, we made also EVB with two relays, button, RT5350F-OLinuXino socket, UEXT connector, USB host, two 100MB Ethernet ports and EXT connector with all unused ports.
The RT5350F-OLinuXin-EVB is also in stock and cost EUR 24 including RT5350F-OLinuXino in it.
Then we decided to make new version with just one Ethernet and LED display in DIN enclosure:
you can see it here how it looks in plastic box:
RT5350F-OLinuXino-DIN is still not complete but will be in stock soon (hopefully end of June). The price will be about EUR 35. It will be nice solution for home automation, serving array of ESP8266 sensors and BLE modules as OpenWRT supports 6LoWPAN.