The two (RFID reader and USB2SER) don't work together very well.
1) You can't power the RFID reader from the USB2SER. You'll need a separate +5V supply for the RFID reader connected to VCC and GND.
2) The RES line on the USB2SER produces a pulse whenever you turn on DTR while the /ENABLE line expects a level that stays low while the RFID reader is to be activated. I'm not sure of the pulse width, but it's probably too short to activate the RFID reader the way it's intended to work. You could just connect the /ENABLE line to GND to leave the RFID reader activated all the time.
3) As NatureTM mentioned, you connect GND on the RFID reader to VSS on the USB2SER.
4) Connect SOUT on the RFID reader to RXD on the USB2SER.
Post Edited (Mike Green) : 6/1/2010 3:43:36 PM GMT
Sorry for the bad info. I bought one of the discount readers at radio shack and got it working with a microcontroller the other day. I just glanced at the USB2SER spec sheet and gave a response when I should have made more of an effort to be sure I was giving good info.
As far as the /ENABLE pulse length, I found that it likes 500ms or greater. It's still just a little flakey at 500 ms and I use 1000 ms because that seemed to work every time. The real "perfect" pulse length is probably somewhere in between, but I didn't spend too much time on finding it, as power consumption is not a major factor in my application.
I'll try to do my research a little better in the future before posting solutions for products I have never used!
Comments
RFID to USB2SER:
VCC to VSS
/ENABLE to TX
SOUT to RX
GND to RES
Correct?
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Jack Maps
eternal noob
The two (RFID reader and USB2SER) don't work together very well.
1) You can't power the RFID reader from the USB2SER. You'll need a separate +5V supply for the RFID reader connected to VCC and GND.
2) The RES line on the USB2SER produces a pulse whenever you turn on DTR while the /ENABLE line expects a level that stays low while the RFID reader is to be activated. I'm not sure of the pulse width, but it's probably too short to activate the RFID reader the way it's intended to work. You could just connect the /ENABLE line to GND to leave the RFID reader activated all the time.
3) As NatureTM mentioned, you connect GND on the RFID reader to VSS on the USB2SER.
4) Connect SOUT on the RFID reader to RXD on the USB2SER.
Post Edited (Mike Green) : 6/1/2010 3:43:36 PM GMT
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jack Maps
eternal noob
As far as the /ENABLE pulse length, I found that it likes 500ms or greater. It's still just a little flakey at 500 ms and I use 1000 ms because that seemed to work every time. The real "perfect" pulse length is probably somewhere in between, but I didn't spend too much time on finding it, as power consumption is not a major factor in my application.
I'll try to do my research a little better in the future before posting solutions for products I have never used!