Feeling electric current with the Thunder Finger and Buzz

“Imagine if chefs couldn’t taste, artists couldn’t see, and musicians couldn’t hear. Humans can’t perceive electric current, so engineers and electricians can never physically feel their work.”

Freelance hardware developer Zack Freedman had enough of only feeling electric currents in the form of zaps. So, he set out to create the Thunder Finger, a device sending information about electric currents to the wearer in the form of haptic feedback, and entered the project in Neosensory’s second developers contest.

“If I could sense the current traveling through a wire, I could literally poke around in my projects and feel the power flowing in the chips chattering,” Freedman explained in an accompanying video. “I’m gonna give myself a superpower.”

The Thunder Finger

The Thunder Finger consists of a magnetic sensor, an Adafruit Feather board, a battery, a glove and Neosensory Buzz.

Freedman’s search for a magnetic sensor capable of measuring both AC and DC led him to the fluxgate magnetometer, “an ultra-sensitive sensor capable of picking up the minute magnetic field formed around a wire carrying just a few hundred milliamps.”

Freedman 3D-printed a flexible finger ring that lets him mount the sensor to his finger.

The sensor, mounted on a flexible finger ring, is then hooked up to the Adafruit Feather board, and connected to a battery. The processor pack is then glued to a weightlifter’s glove. For good measure, Freedman added a colorful matrix display. He finished the project by adding Buzz, a haptic feedback wristband whose four vibrating motors are capable of sending nuanced information to the wearer.

Neosensory Buzz is a haptic-feedback wristband with four vibrating motors.

“Just put on the glove, power up the Buzz, allow the device to self-calibrate, and bring your finger near flowing current. You’ll be able to sense the current pulsing and flowing as you approach,” Freedman writes.

Next Steps

While the Thunder Finger works as intended, Freedman sees potential for improvement given more time.

Freedman added a display to the glove to visualize the electric currents.

“If I had some time to tweak, I could calibrate the DRV425’s response range to better pick up what I’m looking for. I could also feed the output reference voltages into a differential amplifier which would increase our resolution.

“Also, I’m polling the sensor super slow because it makes the code easier to write but we can actually read the fluxgate up to 23,000 times a second. With the right code we could decode PWM pulses, we could pick up audio transmissions we can even sniff 9600-baud serial traffic. I could convert each one to a different tactile texture so I can debug and hack electronics with my finger,” Freedman said.

To read more about Freedman’s entry, click here. To check out his other project, visit his Youtube channel.