Tag Archives: ATtiny84A

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.

μHack is an Arduino-compatible board for Makers of all levels

The μHack is a penny-sized microcontroller looking to bring DIY hardware hacking to the masses.

Created by Silverwing Industries, the μHack is a penny-sized, Arduino-compatible microcontroller designed to bring hardware programming to everyone. The Prescott, Arizona-based startup hopes that the board’s simplicity, flexibility and ease-of-use will make it a suitable option for novice and advanced Makers alike.


Originally appearing on Hackaday and now launched on Kickstarter, the μHack is powered by an ATtiny84A. Its very small form-factor (0.7″ x 0.7” to be exact) allows for the MCU to be embedded in just about anything a Maker may want to hack.

To help facilitate the process, the team has developed a piece of cross-platform programming software for the μHack. Targeted primarily for beginners, the aptly dubbed ezHackStudio features an intuitive interface that enables users to drag-and-drop various functional blocks into the workspace.

“The ezHackStudio supports simple functions, complex functions, various hardware interfaces and all of our booster packs! Ever wanted to make a complex temperature controller or a PID controller to balance a robot on 2 wheels? Well, the ezHackStudio has blocks like the PID block and IMU interface block which makes your job a lot easier! Just make a diagram of your project’s logic and let the ezHackStudio do the tedious coding for you,” the team writes.


The μHack’s I/O ports are very flexible and most of its pins can be used for multiple purposes. With a total of 12 digital I/O pins (out of which four have PWM capability and either have analog input capability), the μHack packs a punch even despite its minuscule size. The μHack is equipped with various common communication ports, such as SPI and I2C, while Makers can also connect UART devices using a Software Serial Library — which is included by default in the company’s drag-and-drop program and available for download for those using the Arduino IDE.

“The μHack alone is already pretty awesome, but we’ve made it even more awesome by developing a wide variety of stack-able booster packs for the μHack that give it a lot more functionality. No more messy jumper wires,” the team writes.

Additionally, the team has its sights set on another board for those who looking to work on more powerful projects. Based on the versatile ATmega32U4, the μHack+ is double the size (measuring 0.7″ x 1.4”) and has twice as many I/O pins as the μHack. The MCU also boasts a built-in micro-USB port. It should be noted that the μHack+ is still in the midst of development, though a larger prototype has already been tested.


Makers can take comfort in knowing that both the μHack and μHack+ are indeed Arduino-compatible, meaning that those who’d prefer to program it old-school with the Arduino IDE can do so with ease. By default, the team emphasizes, both of the MCUs come with Arduino bootloaders programmed into them. In other words, Makers can program them with Arduino C out-of-the-box, or with Atmel’s AVR Studio.

“If you’re using the μHack, just plug in the USB programmer booster pack, hook it up to your computer (whether you run Windows, Mac OS X or Linux) and start hacking!”

Last but not least, μHack features a wide-range of booster packs that can enhance the functionality (and possibilities) of your next project. These include everything from a Bluetooth 4.0 module to an XBee adapter to a motor driver.

Interested? You can head on over to its official Kickstarter page to learn more or back the project for yourself. The board is currently seeking $16,000.