I was trying to find a cheaper, easier to solder solution for putting a USB to serial adapter on a homemade arduino and was wondering if this will do the trick? I'm trying to look at arduino schematics but I can't really decipher them. But I figure this chip has got 2 ports, for pins 0 and 1. Will that work?
I believe you can use vusb, search that and arduino you should find some results,
it uses the atmega328 itself so no additional hardware
no clue how hard. Tho it seems a bit complicated
I etch the boards myself so I wouldn't mind soldering a soic. But anything smaller I'm not sure. I just tried making my own breadboard adapter for some .5mm connectors and it could have gone better. Multimeter says it checks out as far as I can tell but I havn't tested it yet. I hope it gets easier when I upgrade from my 15w radioshack iron. But I don't want to put my eggs in any basket with leads smaller than soic yet, as it were.
Once you have the right equipment and a bit of practice Its really easy to drag solder chips like the FTDI's, a station like the FX-888 will work great, although I use Weller gull wing tips you can do it with a chisel tip just fine. HowToDragSolderSMD.mov - YouTube. As for cost I would imagine maybe using a MSP430 with USB firmware maybe one of the cheapest solutions. Although now I just throw an Atmega32u4 on something if it needs native USB and Arduino compatibility.
For usb-serial, I use a PIC18F14K50. It is dirt cheap (<£2), requires only a couple of capacitors, a resistor, and a 12MHz crystal (with capacitors). It is available in a DIP package, so can be used on veroboard or breadboards, and I seem to recall finding a sketch which allows the hex file to be downloaded with an arduino. It is also available in 1.27mm SOIC, and 0.65mm SSOP.
In case you are interested, I attached the hex file and driver for it, along with the schematic.
If you are making your own board, why bother with USB-to-serial conversion at all? If it is only for programming your board, program it using ICSP instead. If you need USB connectivity for something else, then base your design on the Arduino Leonardo (the chip used in the Leonardo has the USB interface built in).