tim savas



I’ve been building hardware and wanted to develop more skills in analog and digital electronics. Physics-123 is a popular course designed by Tom Hayes at Harvard who authored the companion text, Learning the Art of Electronics. Each week is a chapter in the book. Here is a bit of a journal from the two semesters.

The Fall 2020 analog courses’s problem sets helped build a practical intuition around analog circuits. We started with Thevenin’s theorem and worked our way through passive components, transistors, op-amps and some others. Here’s an index of my problem sets.

Homework Link
Homework 02: RC Circuits link
Homework 03: RC Circuits II link
Homework 04: Diode Circuits link
Homework 05: Transistors I link
Homework 06: Transistors II link
Homework 07: Op Amps I link
Homework 08: Op Amps II link
Homework 09: Nice Positive Feedback link
Homework 10: Op-amps III link
Homework 11: Design Manufacture link

Environmental Sensors & Actuators

I’ve been applying my learning in this course to sensors and actuators for a controlled environment mushroom grow chamber system I am prototyping. Mushrooms enjoy high humidity, low CO2, and moderate temperature. Over the course of digital and analog semesters, I prototyped each of these systems.

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Temp Control

This is an air temperature control board I designed. It uses an LM34 IC which is this really cool IC that outputs .10mV per degree F. The board actuates a heating pad to warm and a fan to cool, according to some tunable thresholds and hysteresis.

Analog Project: Design for Manufacture

For more about the project you can check out the manufacturing materials I designed for it.


Humidity Control

I built a circuit to drive a piezoelectric disc for humidification, using a ‘555 to create a square wave at the piezo's resonance frequency. The oscillator drives a mosfet delivering higher voltage to the disc.


Digital Circuits

For the digital portion of the course I built a computer on a breadboard. Until this point I had only written my microcontroller code on an Arduino, and so it was a fun challenge to interact with the chip itself. We wrote some applications in Assembly language.

Digital Project: CO2 Control

For our project I got this microcontroller to do some neat things like cactuators and collect data from a CO2 sensor. Here are some basic projects I did, collecting CO2 data from a TL6713 CO2 sensor and doing some various actuation with it. A challenge was really understanding the fundamentals of the I2C and UART serial communication protocols.

775 670 3447 / tsavas[@]media.mit.edu