HTTM Backlit Capacitive Touch Switch / Button Sells for about one Dollar

You may have some project that requires buttons to turn on and off devices, or perform other tasks like navigating a user interface or playing games. One interesting and inexpensive solution for this could be HTTM (HelTec Touch Model) capacitive touch buttons that include three pins for power, ground, and the button status, as well as a backlight. You’ll find them on many websites, and one of the cheapest option is a pack of 10 buttons going for $9.91 on Aliexpress.

HTTM button specifications:

  • Voltage input range: + 2.7v to + 6v
  • Signal output – Voltage: + 3.3v; Current up to 500 mA
  • Header – 3-pin with GND, VCC, and OUT
  • Backlight color – red, blue (cyan), or yellow
  • Dimensions – 20.4 x 16.6 mm
  • Operating temperature range: -30 ℃ to + 70 ℃

You’ll find more details on the manufacturer’s product page including a user manual (Chinese only), and their DIYtrade page implies they may have versions with up to four keys:

HTTM is HelTec Touch Model shorthand;
□ → Number of keys: S- single key, D- double keys, T- triple keys, F- four keys;
◇ → Version attribute: C- conventional version, S- Special Edition (customized version);
△ → backlight colors: B- blue, R- red, G- green

But I could not find any of those. The company (Chengdu HelTec Automation Electronics Technology Co. Ltd) also makes some OLED displays, which may be worth checking out.

I learned about HTTM button via Pete Scargill’s blog, and he shot a video showing how to use the switch directly connected to a relay board (The demo starts at the 1:50 mark). Since it’s using capacitive touch, he explains you could place one or more buttons inside a box, and it would still work. Those buttons are also likely more durable than mechanical switches.

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Ramesh MUTHUKRISHNANDeets Recent comment authors
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Heltec also seem to do esp32 esp8266 lora dev boards, not sure why not on their website

Ramesh MUTHUKRISHNAN
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Ramesh MUTHUKRISHNAN

please send me a sample of these touch switches