I have 5 gates and a moving car. I would like to know in which gate the rc car just past by. The gates does not have a power source. First I thought I can use rfid to identify the gate number from the car, however this requires to much power in order to read the passive tags from a 20cm distance. The other idea is to use something like the bar-code scanner with my arduino. Can anybody recommends other easy to implement solution on an arduino?

  • \$\begingroup\$ UHF (ultra high frequency) RFID tags and readers are used in a such scenarios (passive tags, some readers can read from 10 or more meters apart, typical ~5m) \$\endgroup\$
    – Flanker
    Apr 23, 2017 at 13:16
  • \$\begingroup\$ "I would like to know in which gate the rc care just past by" - why? \$\endgroup\$ Apr 24, 2017 at 5:15
  • \$\begingroup\$ Multicopter racers use infrared LEDs transmitting a code to grounded receivers with success, for a similar application. A similar system could be adapted for RC cars, albeit the gates wouldn't be passive. \$\endgroup\$
    – jms
    Apr 24, 2017 at 10:38

1 Answer 1


I've used RFID sensors and tags in a product. The RF tags we used are for short-range stuff. The UHF tags are used for detecting objects from further away, such as containers on lorries from 15 m away.

The UHF readers are off-the-shelf and readily available. You will get a code from each tag so you can tell vehicles apart.

The downside is that the readers are expensive. You don't mention a budget so I'll leave you to weigh this up.

  • \$\begingroup\$ Thank for your help. This is an RC car hobby project. \$\endgroup\$
    – Mokus
    Apr 23, 2017 at 13:25
  • 1
    \$\begingroup\$ @OHLÁLÁ, right...you probably can't afford £100s, then. Unfortunately, you question says car and gates, generally meaning motor car and large barriers. Best you detail the question far more, then: why you're doing this, diagram with sizes, what a 'gate' is, how much you can afford. A lot of paragraphs - the opposite of 'sketchy'. \$\endgroup\$
    – TonyM
    Apr 23, 2017 at 15:13

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