Wireless fm ook reciever over usb. (2400 baud serial uni directional connection)
Why?Need a usb capable fm revciever for cheap data aquisition.
Ti makes a cheap usb to rs232controller ic. It has an internal resonantor so theres no need for a 12mhz oscillator, and aside from the super small ic size, it only requires a small amount of glue components to couple the rf datastream into the recieve line of the usb-> serial converter. For prototyping i etched a board.
|Pre-project tip||Make the traces as large as possible so that the toner transfer paper has more surface to transfer.|
The board was designed in pcb artist (from 4pcb.com). i used a pdf printer , created a pdf and used photoshop to flip horizontally. after printing this out onto toner transfer paper it is ironed onto copper clad board.
attached is the board layout (PDF LINK)
Using a ferric chloride tank, the board is etched untill the only parts remaining are the toner (black) on the fiberglass board. from the image, the board was 1/4 of the way through the etching process. a small portion of the copper was removed from the upper right side of the board.
|3.||In The tank
heres an image of the board in the ferric chloride tank. the bubbles are from a fish tank bubbler. airation and hot temperatures accelerate the stripping of the copper from the fiberglass board.
|4.||Heres a shot of the board 3/4 of the way through the etching process. at this point a majority of the copper has been etched and the remaining parts are the toner protected copper lines.|
|5.||After etching and watching the board of extra ferric chloride, using scotchbrite the toner is removed and the copper traces remain. Now for prep, and adding components|
|6.||More to come as the components arrive|
Rensselaer Polytechnic Institute
Electrical & Electrical Power