New project: External Ruuvi sensor boards


Hi everyone!

We’re planning to build some tiny external sensor boards that could be used with RuuviTags.

I’ll share more info about boards’ dimensions and pinouts later, but before that, would be great to hear if you’ve got some ideas about sensors you’d like to see available.

Currently, following parts are on the list:

  • 9-DoF (acc, magn, gyro)
  • IAQ VOC air quality sensor
  • Temperature
  • Relative air humidity
  • PIR
  • Photodiode
  • Buzzer
  • High brightness LED
  • IR LED
  • Push button

Not all the features will be supported simultaneously but a set of different kinds of board variants can be manufactured and made available for order.

Idea behind these external sensor boards is to enable new maker(ish) uses for RuuviTags and also make more serious prototyping with new features quick and easy. These boards and their pinouts are aimed to be be also Grove compatible. Additionally, the next RuuviTag PCB revision may gain a connector compatible with these new boards. This would remove the need of soldering.


What is the planned temperature range? Anything covering +4 … +98 celsius would be awesome


Sensitive microphone with 3.3v preamp in a sealed enclosure no more than 5mm dia with a lead about 50mm long.

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What variables would you like to measure in such high temperatures? Temperature? Almost all electronics IC chips are rated to work at max +85C.


That would be a pretty good reason to have an external sensor board :slight_smile:. Maybe a thermocouple or a resistive sensor chip could withstand autoclave-level temperatures?

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This would be just temperature, monitoring the performance and ramping rate of a peltier element.


What about include a power plug (3.6V) on the sensor board that power the board and the Ruuvi?
So its easy to make 3. party boxes to hold all 3 parts (Ruvvi, Sensor , Battery)
like my 1/sec/15 years version


Thermocouple (e.g. Amplifier MAX31855) temperature sensor would be extremely useful for fireplace, grill and sauna use cases! RuuviTag to measure ambient temperature and thermocouple to measure smoke channel or fire place temperature.


Light/lux sensor to measure ambient light.


Current monitor, with accumulator or averaging. Something like the INA226, or so. Or a Maxim state-of-charge IC.


Is there a way to set up a poll on this forum or elsewhere?


Is a PIR a

Passive infrared sensor



Yes, it detects presence in area.


How a about an FSR? That would host for a range of new uses to RuuviTag:-)


Do you mean a force sensing resistor, e.g. a strain gauge?
Adding one on a same board with other sensors would probably expose the other sensors to too high mechanical stress, but we can consider it once the first board is out.


Yes, a force sensing resistor - but not actually ON the board. More like a connection that could be easily used for connecting an FSR (or several depending on physical space available) + software support on RuutiTag side to easily utilise it. Currently no board offers integration of FSRs with an easy way to transfer the data in BLE broadcast mode.


@lauri In regards to the temp range exceeding 85C, the DS18b20 is a very inexpensive 1-wire temp sensor with a range of -55C to 125C.

Any 1-wire sensors (temp, humidity, etc) are welcome.

I am using PLCs that support 1-wire sensors. I can run a few wires through a facility (or misuse a LAN cable), and then drop sensors anywhere I want… they simply show up on the “1-wire network”.


Actually, we’re already prototyping with TMP117. It’s a lot more accurate sensor and can measure temperatures from –55°C to +150°C.

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what about an Thermocouple interface?


It certainly would be useful for something like oven thermometers. It might even be enough to activate both pull-up and pull-down resistor on ADC and take differential measurement off the thermocouple, with no extra components required.

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