The LM3915 is another popular IC that can be used to build interesting circuits. It is designed to drive 10 LEDs depending on the analog voltage signal applied to the input. The LM3915 has an adjustable voltage reference and each of the LEDs represent a 3dB step, this makes it Read more…
Building a Bluetooth speaker from the ground-up is a challenging task, but thankfully, we have pre-programmed modules that can be used to make it much simpler. We will use one such Bluetooth audio module to build a Bluetooth speaker. The BBox 2 contains two modules called blobs, which further simplifies Read more…
We will now use the ISD1820 IC to build a voice recorder. The ISD1820 is a dedicated voice recorder IC and we will be using the reference circuit contained in the datasheet. The ISD1820 works at a maximum of 3.3V, so make sure you connect the right voltage output before Read more…
We will now look at two new logic gates and we will use them to create an extremely basic combination lock. The 74HC86 consists of 4 XOR gates which have 2 inputs each. The output of an XOR gate is LOW when both the inputs are the same (either HIGH Read more…
The heartbeat or breathing circuit is a nice little LED project that makes use of a relatively simple circuit. We’ve used the LM358 op-amp in the previous project and to quickly recap: it’s an analog device whose output is the difference between the voltages at its two input terminals. Transistor Read more…
We’re going to now build an electronic candle using a 555 timer and an op-amp. To give us a candle-like effect, we will be using a flicker LED which has two terminals and can be used as a standard LED. This is what the schematic looks like. We configure the Read more…
We’re now going to look at two new components – the CD4026 counter and the 7-segment display and we’re going to use them to build a simple reaction timer circuit. A 7-segment display is nothing but 7 LEDs grouped and arranged in figure 8 along with another LED that acts Read more…
Another interesting circuit that can be built using the binary counter is a roulette like LED wheel. It’s pretty much based on the same principle as before so let’s take a look at the schematic. The 4017 is used like before but we add a total of 10 LEDs which Read more…
A binary counter can be used to create some interesting circuits and an electronic dice is one of them. The circuit is very similar to the previous one so let’s start by taking a look at the schematic. We have a 555 timer configured in the astable mode, but instead Read more…
We will now use a new IC to help us count events. The CD4017 is a binary counter that has 10 output pins. Initially, the first output will be 1, but when a clock pulse is sent to the clock pin, the second output will be a 1, while the Read more…