LoFi is a low-power, low-cost way to connect sensors to the Internet

LoFi is a small, affordable, auto-transmitting module that Makers can attach to any appliance or project.

With the emergence of the Internet of Things, it’s only a matter of time before the walls of homes are adorned with smart gadgetry and nearly everything around us are laden with sensors. However, the price point of these devices keeps many out of reach for a vast majority of consumers. Aside from that, there are countless third-party transceiver modules and data loggers available on the market today that are still a bit pricey and tend to be too complicated to deploy in volume.


In an effort to solve this conundrum, Maker David Cook has devised a readymade, self-transmitting module that enables hobbyists and hackers alike to add wireless connections to any appliance or DIY project in a much more affordable, less power manner. A user simply needs to attach the aptly-dubbed LoFi to circuit points or sensors throughout a home or garden, and its acquired data can be relayed to either a PC or sent to Internet via Wi-Fi. There’s no programming or protocols to learn, or carrier boards to be made. The best part? The entire thing will cost less than a morning cup of coffee (approximately $3).

“Using your desktop or laptop, you can set trigger levels on individual modules to tell them when to transmit. For example, send an update when the voltage changes by more than 1 V on the vibration sensor near the garage door opener. You can also set the module on a timer, such as hourly on your garden monitor,” Cook writes.

The low-cost, low-power solution is comprised of a cheap transmitter and receiver along with a pre-populated board that users can wire with appliances or projects, ranging from a doorbell to a thermostat. By pairing sensors and a battery, LoFi can be used as a standalone sensor station outdoors. The pre-programmed board boasts five analog inputs, an internal temperature sensor, a voltage reference and is based on an ATtiny84A, which is tasked with monitoring the inputs and outputs of the data. The compact sender module is also equipped with a red and green LED to indicate status, and an optional coin-cell holder and pushbutton to manually activate transmission. What’s more, sensors such as light, humidity and vibration, and an infrared motion detector can be added as well.


After the device is all wired up, Makers can take their smartphone, attach it to the Serial cable and read all sensor values. Users can set minimum/maximum thresholds and a timer by which they’d like LoFi to relay the data. Once configured, the inexpensive transmitter and receiver are attached, connected to a listening gateway, and linked to a home PC using the aforementioned Serial cable. By doing so, users can receive all the information that has been sent. Even better, a Wi-Fi board can be added to enable wireless transmission to Internet or a home network. It should be noted that LoFi is compatible with data.sparkfun.com, a free open-source Internet repository.

LoFi is capable of achieving low-power by being in deep slow mode most of the time. On average, the module consumes just 18μA of power, allowing it to last a year on coin-cell or 10 years on a AA batteries. Given its power consumption and 1.25 square inch package, the board can be used in a wide-range of applications.

For instance, the combination of LoFi, a tilt ball switch and some velcro inside a Tic-Tac box can serve as a garage door detector. Or, LoFi, an infrared reflective sensor and a bead jar can alert a user if they’ve got mail. By gutting an iPhone charger and adding a coin cell, LoFi can create a disguised in-house temp monitor. The list goes on and on…

Want to learn more? Head over to the project’s official Hackaday.io page here. Feeling inspired? Submit your idea for some Hackaday Prize stardom.

3 thoughts on “LoFi is a low-power, low-cost way to connect sensors to the Internet

  1. Pingback: 1p – LoFi Connects Things to the Internet for Less Than a Cup of Coffee | Profit Goals

  2. Pingback: 1p – LoFi Connects Things to the Internet for Less Than a Cup of Coffee | blog.offeryour.com

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s