PIC18F2550 KS0108 Graphical LCD Oscilloscope

Using the PIC18F2550 GLCD Text Test as a basis for further experimentation, I put together a simple and accurate graphical oscilloscope using a PIC18F2550 microcontroller and a AGM1264F graphical LCD. The oscilloscope measures the average voltage, the maximum voltage, the minimum voltage, the peak-to-peak voltage, and the zero-crossing frequency for a DC signal over 100 samples. The oscilloscope has a built in edge trigger function that can be set to capture on rise or fall (or disabled altogether). The time scale for the display is variable and can be easily redefined using the changeTimeDivision function. Likewise, the voltage range can be change to 0-5V, 0-2.5V, and 0-1.25V. The main limitations of this oscilloscope include relatively slow acquisition time and sampling rate (~60kHz) and the fact that the inputs are limited by the constraints of the internal ADC. However, it is a very nice display and I highly suggest you view the videos to see it in action. Read More

PIC18F2550 USB HID IO

After completing the PIC18F2550 USB HID Oscilloscope, I decided to expand upon the project and firmware to include multiple analog inputs and digital i/o. The base firmware for this project is the same as the PIC18F2550 USB HID Oscilloscope‘s; however, more features have been added that allow the user to access the PIC18F2550’s Port B for digital i/o. In addition, the firmware now allows the user to access the AN0-AN4 analog pins for monitoring and data acquisition. Read More

PIC18F2550 USB HID Oscilloscope

This is a project that I’ve been planning on putting together for a long time. After creating an oscilloscope using a PIC12F675, I wanted to create a simple and effective USB oscilloscope using the higher performance PIC18F2550. During the development of this project, I learned quite a bit about USB HID communication, which allows me to quickly and effectively communicate with the desktop computer. Using HID means that this oscilloscope does not require drivers (only the oscilloscope software). Read More

PIC18LF2550 Wireless 3-axis Accelerometer

Having a 2.4GHz Serial Link is helpful, but what kind of applications could it be utilized for? Well, I had a number of 1-axis accelerometers from Freescale (graciously provided by their samples department for my electronics lab projects), which I could use detect object orientation. Making the accelerometers wireless would allow for remote sensing of object orientation, which could be applied to virtual reality or possibly augmented cognition. In any case, it allows for some fun experimentation! Read More