The Olduino is a retro-Arduino. It uses an RCA 1802 processor from the 1970s but adds hardware and software so it can function like an arduino and use some arduino add-on shields. ... The Olduino has hardware support for high speed SPI(Serial Peripheral Interface) through a set of shift registers on the olduino board. It can do high-speed serial communications to an attached PC through an onboard AVR slave processor.
What's the stack up for your little Arduino 1802 stack. I read a couple of articles about range finders. It appears that you're using such a device. What's is the source of the range finder module and the LCD module?
The rangefinder is a stock ultrasonic item. Parallax makes them and Seeed Studio. The LCD is from a Nokia N5110 phone.
Both of them are sold by sparkfun for use with arduino. You can see more info about the ultrasonic ranger at https://olduino.wordpress.com/vcfmw/ultrasonic-ranger/