Member Since: February 15, 2007

Country: United States



EE, iPhone developer,



  • This is a nice little device. The one thing that I found unclear from the data sheet is a “minimalist” set of connections to get the device to work. So I’ll note that here: * Power: Pin 11 to 5VDC, Pin 1 to GND. * Enable: Pin 2 MUST be tied high. Can’t just let it float. ASCII * Output: Pin 7 must be grounded. * Data: Take your TTL output on Pin 9. I fed mine into a Roving Networks module to connect the RFID unit to my home network.
    The other thing that faked me out at first was not having any “known” 125kHz RFID cards. I had a “badge” that I THOUGHT might work but I see now that there are TWO RFID standards (at least) and I think my badges are probably the 13mHz MIFARE kind. Do yourself a favor and if you buy one of these, spend another two bucks and get one of the SparkFun RFID cards so you’ll have a known test article.
    I’m toying with the idea of using this for access to the pool my wife manages in the summer. see: http://www.youtube.com/watch?v=aUsNaK867cE for a video of my circuit board construction for this unit. Also shows direct ink jet printing process I use in some detail. If anyone has questions about modding an Epson Arttisan 50 printer to do this, just drop me a line. Unfortunately, I didn’t think to video the process (g). It isn’t hard and it works VERY well. If there’s enough interest, I may try to create some how-to video for that in retrospective.
    (note, in my use case I had 6V power so I used a 5.1 V 1W zener in series with a 220 ohm 1 W resistor to take the 6 down to 5. This is what you see in the video on the module. I have this little WiFi breadboard that I use to test various devices such as the RFID, GPS modules etc. which supplies two grounds, RX,TX,3.3V regulated and VBATT. This way I can test a lot of different modules that output RS232 easily with my home network.)

  • Thanks to all of the folks that posted here. I used this neat component as the sensor to control the temperature of a reflow soldering hotplate using an Arduino and a sketch I wrote based on info I got from posts here. The details are too long to post here but I wrote up the whole thing on my site and wanted to pass along a link:
    I’m getting SUPERB SMT soldering results using this rig and this is the first time I’ve ever done SMT work. This little IR thermometer is just the ticket. Feel free to write me if you have any questions I haven’t covered in the writeup and code posted on my site (don at ayefon.com)

  • I’m having good success with the Roving Networks stuff in general. I took the conservative route for my first project and bought the 370M which is a complete package for rs232 stuff. That worked so well that I bought the RN121 version they sell and interfaced it to an LS20031 GPS module that I bought here to make a wifi gps. That works well also. I’m adding code to my iGeoCacher app so that iPod users and iPad (basic non 3G model which has no GPS) can use my software as well. I’ve also used these modules to wifi enable my old CM11A X10 controller so I can ditch the PC and just issue commands directly from an iPod/iPad/iPhone to the CM11A directly. This module with RS232 level conversion makes an excellent add on for CM11A’s allowing me to make “smart remotes” out of all my iOS4 hardware. If you want to make something serial into a wifi addressble device, the roving networks module is the best I’ve found. I’m just “one guy in a garage” but I found the Roving Folks to be very helpful with a few design questions I had including a very friendly engineer pulling solo duty during Thanksgiving week. Check out the Roving Networks site for extra documentation and data sheets.