Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

Programmable Timer on a PIC18F4550

Victor got forced into building this project because a 30+ year old mechanical timer for the house heating gave up on them – instead of buying a new one, he decided to learn new stuff and build something digital. After talking to a few people he used a PIC18F4550 along with a Dallas Maxim DS1307 real time clock. The chips communicates through I2C and to still keep time even if power goes off a back up battery is used. Now you need to have something to display the time stuff – this project comes with a 16×2 liquid crystal display (that also comes with a backlight!). You would also need something to control and adjust the time – this comes with six momentary switches. As I mentioned earlier this was built for a heater so Victor threw in an LED (Light Emitting Diode) to indicate if the heater is on or not. Continue reading

Real-time Spectrum Analyzer on a PIC18F4550

We usually see spectrum analyzers as decorations to audio equipment – bouncing sets of bars that go up and down depending on what frequency the played tone is. I remembered building a similar project a few years back – its called a Led VU-Meter, though its nothing compared to the complexity of the math behind this project. This real time spectrum analyzer takes in audio signals, amplifies and level shifts it to fit the 0-5V range of the PIC18F4550’s 10 bit analog to digital converter – this is all done through an LM386 operational amplifier. Now the tricky part in this project is called coherency – this is the scheme where it should follow fs/fi = m/n, fs is the sampling frequency of the PIC18F4550’s ADC, Fi is the frequency of the sound being sampled and n is the number of samples. This is a requirement for FFT (which is entirely implemented in C!) or fast fourier transform. Each of the bars/columns of the 128×64 dot-matrix LCD on the spectrum analyzer would be a frequency bin in FFT. Continue reading

LED array Digital clock

This is another digital clock that uses an bi-color LED array to display time. It’s special purpose is to indicate time when child has to go to bed. As it able to do so in two colors red and green, so no need to learn clock – just follow the color. Red means – go to bed, green time to get up. Hard to say if it’s working this way – children simply don’t love rules 🙂 Anyway this is great project that is based on multilevel board design to make it compact. Clock is run by PIC18F4550 microcontroller. Continue reading

The Create USB Interface

The Create USB Interface or also known as “CUI” is the new technique for computing that generate music and visual arts. By using CUI, it allows you to bind physical processes or actions to corresponding digital expressions. The CUI provides the necessary electronics to capture sensor input or control actuator output. For your information, the CUI is coming with a USB port, a power LED, a Reset switch, a Programming switch and a prototyping area. The PIC18F4550, a versatile microcontroller is used as the main heart of the CUI board. The PIC18F4550 features thirteen A/D inputs, eighteen general I/O ports and an efficient RISC-like instruction set. Normally, the CUI uses one of the PIC’s general I/O ports, while the remaining ports are available for user applications to be built in the prototyping area. Honestly, the total cost of the CUI is around $30 per piece. With a PIC and CUI board, you can do many useful things: A musical interface: The CUI board can be programmed to convert analog sensor inputs to a standard USB protocol. A novel visual interface:… Continue reading

The USB Auxiliary Display is Superb!

Have you ever thought to develop a USB auxiliary display by your own? Ok, you might think it’s going to be a very tough project, but you’ve the wrong impression about it! Many people have created million of auxiliary displays for computers and most of them are for commercial use! The majority of them are serial port based, and many of the ones that are USB based use a USB to serial converter. There are mostly expose the display to Windows through a virtual COM port. The display that you’re going to create here is uses the PIC18F4550 with WinUSB and it don’t expose a virtual COM port at all! Basically, the display itself is a 128×64 parallel graphical model GDM12864H from SparkFun. The display will include a keypad and a bright backlight. As a result, it’s capable of displaying text, in either horizontal or vertical mode, and it can running in a pure graphical mode if you want it to be! Since the PIC18F4550 is used to control the display and scan the keypad, thus both the PIC and… Continue reading

The US2B Radar – the Truly Radar That will Put You on the Test

Have you ever think to develop a high-tech and sophisticated US2B radar by yourself? You might think that this totally a mission impossible project, then you is wrong here. Before you starting the task, you’re better prepare these following components: PIC18F4550 microchip (microcontroller) An ultrasonic range sensor A old bipolar stepper motor (This for the motor turning purpose) Below here is the figure for the finished radar with the USB missile launcher beside it. The stepper motor will turn the ultrasonic range finder in 360 degrees and reverse (Cool, isn’t it?). When two measurements have been made, the PIC will send out the data to the PC by using an asynchronous interrupt transfer. The timer in the PIC controls the stepping motor turning speed. Continue reading