While many of us have banished land line telephones from our houses, there are still quite a few people who utilize POTS lines today. These analog phone systems use Dual Tone Multi Frequency (DTMF) ...

Decoding this bit stream into ASCII hex values is an ideal job for a low-cost 8-bit microcontroller. Using a microcontroller with onboard flash memory, such as the NEC Electronics µPD78F9418A ...

This infrared transmitter use PWM (pulse width modulation). The transmitter is equiped with LM567, tone decoder circuit. Audio signal ( at least 50mVvv ) is amplified with T1 and then it is used to ...

[spencerhamblin] is starting his explorations into digital electronics the hard way: reproducing a “simple” IC’s functionality by wiring up a board full of discrete transistors. In this case, the end ...