Fresh hacks every day
[Nick] and [Simon] both have home security systems with a monitoring service who will call whenever an alarm is tripped. For [Simon] this ends up happening a lot and he wanted to change the circumstances that would trigger a call. Because of company policy the service is inflexible, so he and [Nick] went to work cutting them out of the … Read the rest
[Lior] wanted to cancel the monitoring system for his home’s alarm, but he didn’t want to stop using the alarm all together. The trick is to rig up some way to monitor it himself. It would have been simple to have it just call him instead of the alarm company since the system just uses a telephone connection. But this … Read the rest
We have no idea why, but since we featured Botiful, the Android-powered telepresence robot a few days ago, the tip line has been awash in robot/Android mashups. Here’s a few of the cool ones.
[Stef] used a Samsung Galaxy S3 to control an old rc tank. The Android sends accelerometer and gyro … Read the rest
Nope, no microcontroller here, just a full-blown cellphone used as the brains of this little robot. The secret behind how it works is in the sounds the phone makes. The touch tones, known as DTMF, are monitored by the circuit mounted on the front half of the chassis and are responsible for driving the motors.
[Achu Wilson] built the … Read the rest
If you’ve ever wondered about the best way to detect dial and DTMF tones from a phone line, [Debraj] is your man.
[Debraj] built a DTMF detector using the Goertzel algorithm. Normally, when we think about detecting tones, we pull FFT out of our bag of tricks. The Goertzel algorithm isn’t as computationally complex as FFT and can be … Read the rest
We’re all familiar with IVRS systems that let you access information using a touch-tone telephone. [Achu Wilso] built his own version which uses a cellphone, microcontroller, and computer.
The cellphone is monitored by an LM324 op-amp with an attached 555 timer chip. When a call comes in the voltage on the headphone output goes high, activating the timer circuit. … Read the rest
[Victor's] girlfriend works at a museum and enlisted his expertise in designing an interactive detective game for kids visiting the museum. The vision was for the kids to discover phone numbers that they could call for clues. Originally he planned to display the clues on a character LCD, but obviously it’s much neater to hear the clues in the … Read the rest
Subscribe for weekly videos
Recent comments