I recently purchased this HM-10 board. I can connect to it and everything, so it works perfectly. I ran into a problem, the range is only around 7 feet.

How can I increase the range? I need it to go around 30 feet. Thanks!

https://www.seeedstudio.com/wiki/images/c/cd/Bluetooth4_en.pdf http://www.pridopia.co.uk/pi-doc/BT4.0-HM-10-Serial_Port_BLE_Module_Master_Slave.pdf

  • \$\begingroup\$ Does it have an antenna connection, have you connected one? \$\endgroup\$ – user1582568 Feb 17 '16 at 0:21
  • \$\begingroup\$ @user1582568 It has exposed metal, in the shape of digial pulses like |__|--|__ \$\endgroup\$ – DarkHorse Feb 17 '16 at 0:22
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    \$\begingroup\$ Time to check the manual \$\endgroup\$ – user1582568 Feb 17 '16 at 0:36
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    \$\begingroup\$ According to the datasheet, you purchased a counterfeit HM-10 . There is some irony to this. \$\endgroup\$ – crasic Feb 17 '16 at 2:12

It appears that you have a phony HM-10. This is part of the price you pay for ordering cheap from Amazon. If you want to increase range, you can make sure that it's not close to anything metal/conductive.

You could try connecting an external antenna, but you'd have to trim the length to get it right. It's quite likely that the onboard antenna has it's own matching network to match its high impedance to the low impedance of the chip's output. You'll need to fiddle around with wire length to find out how long to be. Be careful, you could destroy the product if you overheat the PCB with your iron, or maybe even blow the chip due to a high SWR.

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  • \$\begingroup\$ IIRC the CC2540 has a maximum output of +4 dBm. \$\endgroup\$ – Chris Stratton Feb 17 '16 at 5:08
  • \$\begingroup\$ Ha. OK, then take a 100 foot long piece of wire and run it around the house as an antenna. That'll get you some range hopefully. \$\endgroup\$ – Daniel Feb 17 '16 at 14:24

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