How do I detect the presence of another specific item electronically at low price (I can not afford an RFID reader)?
I trying to create a system that remotely detects a single electronic item without having to purchase an expensive RFID tag and reader. I also think that a proximity sensor can detect the presence of any item, rather than a specific and unique. Also, if possible I would like the compact solution to incorporate elements to be placed on a bicycle and a keychain. All ideas are welcome. Thank you!
A book of information called "sensors electronic evil genius "can help or if you just want an RF detector, then get one and some shops. Model # SH-055DV.
 10125Khz RFID RFIC Proximity ID IC S50 Card ReaderIC US $538.00 |
 NEW WASP CLOCK 3100 RF PROXIMITY READER ETHERNET US $469.99 |
 10pc NEW HID RWK400 Proximity Card Keypad Reader 6131B US $399.96 |
 Access control Keri Systems P650 proximity reader US $382.14 |
 KRONOS PROXIMITY READER MINIPROX KIT 8600732 009 US $325.00 |
 10x 125Khz RFID EM4100 Proximity ID Card USB ReaderID US $299.00 |
 Access Control Long Range Proximity Card Reader US $284.10 |
 USB RFID Proximity Card Reader Employee Time clock US $275.00 |
 NORTHERN COMPUTERS MOTOROLA PR 10 PROXIMITY PROX READER US $249.95 |
 Locknetics LC PX95XTR83 Proximity Reader iButton US $224.95 |
 Access control Keri Systems MS7000BX proximity reader US $209.57 |
 CHECK POINT AC 151 SG Proximity Card Reader MINI FLUSH US $199.95 |
 VIKING HID 1 HID1 ENTRY SYSTEMS PROXIMITY CARD READER US $169.95 |
 NORTHERN MOTOROLA A 120 PROXIMITY READER US $159.95 |
 SiLENT KNiGHT 4310 MOTOROLA PR 10 PROX READER PROXiMiTY US $149.99 |
 NORTHERN MOTOROLA ARK 501 PROXIMITY READER INDALA US $149.95 |
 RF IDeas pcProx proximity Card Readers 1 Access Card US $141.90 |
 Seco larm PR 112S A Stand alone Proximity reader US $139.67 |
 NORTHERN COMPUTERS FP3236A FLEXPASS READER PROXIMITY US $119.95 |
 PKG100125Khz RFID Proximity ID TokenMG236B READERYEL US $116.95 |
 PKG100125Khz RFID Proximity ID TokenMG236B READERRED US $116.95 |
 PKG100125Khz RFID Proximity ID TokenMG236B READERBLU US $116.95 |
 PKG100125Khz RFID Proximity ID TokenMG236B READERGRN US $116.95 |
 PKG100125Khz RFID Proximity ID TokenMG236B READERGB US $116.95 |
 ioProx Kantech Proximity Reader 225 XSF P225XSF NEW US $100.00 |
 NORTHERN COMPUTERS HID PR 2X PROXIMITY READER PROX US $99.95 |
 NORTHERN COMPUTERS HID 6030AGR00 PROX PROXIMITY READER US $99.95 |
 Westinghouse 2814A Proximity Reader NEW US $99.95 |
 Oval Proximity Card Reader access control US $92.10 |
 NORTHERN COMPUTERS MOTOROLA ASR 110 PROXIMITY READER US $89.98 |
 NORTHERN COMPUTERS MOTOROLA ASR 503 PROXIMITY READER US $89.98 |
 NORTHERN COMPUTERS MOTOROLA ASR 110 B PROXIMITY READER US $89.98 |
 NORTHERN COMPUTER MOTOROLA PR ASR 500 PROXIMITY READER US $89.95 |
 NORTHERN COMPUTER MOTOROLA ARE 142 PROXIMITY READER US $89.95 |
 NORTHERN COMPUTER MOTOROLA PR ASR 120 PROXIMITY READER US $89.95 |
 NORTHERN COMPUTER MOTOROLA ASR 505 PROXIMITY READER US $89.95 |
 NORTHERN COMPUTERS HID 5350D 1 PROXIMITY PROX READER US $89.95 |
 Honeywell NexWatch DR4201 Digital Proximity Reader US $89.95 |
 NORTHERN COMPUTERS 4045agk0 ENTRY PROX PROXIMITY READER US $89.95 |
 Access control security keypad proximity card reader US $85.43 |
 HID Proximity Card Reader Lot 4 Thinline ll MiniProx US $79.99 |
 RADIONICS BOSCH D8229 Access Keypad Reader Proximity US $79.99 |
 RADIONICS BOSCH K2001 Low profile Proximity Reader HID US $79.99 |
 Indala Keyscan Proximity Wall Reader Black PX 605 US $79.99 |
 NORTHERN MOTOROLA FP605 PROXiMiTY READER FLEXPASS US $79.95 |
 NORTHERN COMPUTERS ASR 603 ASP PROXIMITY READER PROX US $79.95 |
 NORTHERN COMPUTERS ASR 603 ASP PROXIMITY READER PROX US $79.95 |
 NORTHERN COMPUTERS PR ASR 603 ASP PROXIMITY READER PROX US $79.95 |
 NORTHERN COMPUTERS RE 2A 1033X PROXIMITY PROX READER US $79.95 |
 NORTHERN COMPUTERS fp610bk PRO PROXIMITY READER US $79.95 |
 NORTHERN COMPUTERS ASR 500 ASP PROXIMITY READER INDALA US $79.95 |
 Access control Keri Systems P300 proximity reader US $79.29 |
 HONEYWELL OP40HONE PROXIMITY READER WITH 3 BEZELS NEW US $79.00 |
 Sielox Checkpoint Proximity Card Reader 0882580 US $75.00 |
 NORTHERN MOTOROLA ASR 500 ValueProx PROXIMITY Reader US $69.98 |
 KERRI SYSTEMS KSi 10E PROXIMITY READER KEY CARD READER US $69.95 |
 NORTHERN COMPUTER MOTOROLA PR ASR 112 PROXIMITY READER US $69.95 |
 HID ProxPro II Proximity Reader Model 5455BGN00 New US $69.00 |
 125Khz RFID RFIC Proximity ID IC S50 Card USB ReaderIC US $68.00 |
 ELK M1PR Keypad Plug in Proximity Reader US $62.95 |
 HID 5355 AGN00 ProxPro Proximity Access Card Reader NEW US $60.00 |
 3 Honeywell Proximity Card Readers Brand New US $60.00 |
 INDALA MOTOROLA NORTHERN PR ASR 110 PROXIMITY READER US $59.99 |
 RADIONICS ^ K2001 Low profile Proximity Reader HID US $59.99 |
 NORTHERN COMPUTERS MOTOROLA ^ ASR 503 PROXIMITY READER US $59.98 |
 NORTHERN COMPUTER MOTOROLA FP503 PROXIMITY READER US $59.95 |
 NORTHERN COMPUTER MOTOROLA ^ ASR 505 PROXIMITY READER US $59.95 |
 NORTHERN COMPUTER MOTOROLA FP 4551 A PROXIMITY READER US $59.95 |
 NORTHERN COMPUTER MOTOROLA A 3B 12V PROXIMITY READER US $59.95 |
 NORTHERN COMPUTER MOTOROLA PR 3 PROXIMITY READER US $59.95 |
 Honeywell OP30HONE OmniProx Proximity card reader US $59.00 |
 Access control Outdoor Wiegand Proximity Reader US $57.43 |
 KEYSCAN K PROX 2 HID COMPATIBLE PROXIMITY READER 125KHZ US $50.00 |
 NORTHERN COMPUTERS HiD 5365CBT00 PROXiMiTY PROX READER US $49.99 |
 NORTHERN COMPUTER MOTOROLA ^ ASR 112 PROXIMITY READER US $49.95 |
 Indala Northern Computers ASR 505 Proximity Reader NIB US $49.95 |
 Casi Rusco 941 W Proximity Reader US $49.00 |
 Proximity Thin card reader access control US $47.81 |
 125Khz RFID Proximity ID Identification USB ReaderID US $44.99 |
 125Khz RFID EM4100 Proximity ID EM Card USB ReaderID US $44.99 |
BioEntry Plus Fingerprint Reader