Archive for May 2011

Building a USBPICProg PIC Programmer

I mentioned in one of my previous posts that I decided to give PIC family MCUs a spin after having been working with AVR chips for sometime. From a pure technological stand point PIC programming and AVR programming are not all that different, especially if you are using a high level language like C. But the AVR world definitely seems to have a few advantages in the open-source arsenal such as avr-gcc and Arduino. Continue reading ‘Building a USBPICProg PIC Programmer’ »

Troubleshooting USB Circuit

I have built some circuits that interface with computer USB ports. On several occasions, I had built the circuits but for whatever reason they did not seem to work. Since most USB firmware is rather complex in nature, it is usually useful to first identify whether the issue at hand is related to hardware or software. Continue reading ‘Troubleshooting USB Circuit’ »

A Dual Temperature Display With Humidity Measurement

I built a digital thermometer a couple of weeks ago. This thermometer uses an LM19 sensor calibrated for measuring a wide temperature range (-55 – 130 Celsius, -67 – 266 Fahrenheit) for outdoor temperature measurement and an SHT21 digital thermometer with humidity measurement for indoor use. Continue reading ‘A Dual Temperature Display With Humidity Measurement’ »

An 8-Digit 7 Segment Display

I built a 4-digit 7 segment display last year. In that design, I used four 74HC595 shift registers to drive the four individual 7 segment displays, with one for each digit. So when I wanted to build an 8-digit display, I thought about using the same design with eight 74HC595s at first. But it seemed that the soldering would be a lot more challenging on the prototype board as there will be 8 chips and 64 resistors to solder. Continue reading ‘An 8-Digit 7 Segment Display’ »