I was lucky enough to begin programming computers almost 50 years ago. I have fond memories from my first FORTRAN program on the PLU mainframe to more recent do it yourself projects on modern day microprocessor based systems. About five years ago I was introduced to system on a chip (SOC) microprocessors that included I2C bus interfaces, analog to digital (ADC), and digital to analog (DAC) hardware. I was able to relive my experience at working on real-time systems at Boeing and Control Data Systems. I plan to use this site to share some of my fun projects.
Sample of my Arduino, Espressif, and Raspberry Pi projects.
My first major project used a single ATmega328p processor to control six major environment sensors and communicate to an nRF24L01 radio router.The measurements were temperature, humidity, gas, light, vibration and sound. I used NE555 timer chips to oscillate an alarm buzzer and provide a real-time interval interrupt to the processor's scheduling code. An IR sensor was used to receive messages from a standard TV infrared remote control to change system modes and enter a variety of other commands. A MCP23017 chip added 16 I/O ports to reach all of my digital sensors using the I2C bus. A PIR motion sensor was added to detect human presence or activity. I added a NPN transistor as a switch to inverter the IR signal to indicate activity or reception of IR commands. A couple of DIP switches added a way to customize the boot up process.
