Sensors and Sensor Circuit Design

This course can also be taken for academic credit as ECEA 5340, part of CU Boulder’s Master of Science in Electrical Engineering degree. After taking this course, you will be able to: ● Understand how to specify the proper thermal, flow, or rotary sensor for taking real-time process data. ● Implement thermal sensors into an embedded system in both hardware and software. ● Add the sensor and sensor interface into a microprocessor based development kit. ● Create hardware and firmware to process sensor signals and feed data to a microprocessor for further evaluation. ● Study sensor signal noise and apply proper hardware techniques to reduce it to acceptable levels. You will need to buy the following components to do the two course projects based on the videos in this module. Note that if you have already purchased the PSOC 5LP PROTOTYPING KIT, you do not need to buy it again. These parts may be purchased off the Digikey web site, www. Digikey.com. Or, you may obtain the specs from the site, and purchase them elsewhere. These are the part numbers typed out, so you can copy and paste them into the Digikey web site. You will need one of each part. 428-3390-ND NHD-0216BZ-RN-YBW-ND 570-1229-ND A105970CT-ND Additional equipment needed: • Wire - various gauges and lengths • Breadboard • Oscilloscope – suggested models are: o PICOSCOPE 2204A-D2 available on www.digikey.com or o Digilent 410-324 | OpenScope MZ available on www.newark.com Depending on your budget, you can also investigate these models: o Hantek HT6022BE20MHz - https://www.amazon.com/dp/B009H4AYII o SainSmart DSO212 - https://www.amazon.com/dp/B074QBQNB7 o PoScope Mega50 USB - https://www.robotshop.com/en/poscope-mega50-usb-mso-oscilloscope.html o ADALM2000 - https://www.digikey.com/en/products/detail/analog-devices-inc./ADALM2000/7019661

• Thermal Sensors
• In module 1 you will learn how to specify and use temperature sensors in an embedded circuit. First, you will learn about common types of sensors and actuators found in common products such as smart phones and automobiles. Then you will get a high-level overview of analog and digital interfaces, followed by a deep dive into thermistors, RTD’s, and thermocouples. For each of these three types of thermal sensors, we define the core theory and formulae, give you examples of how commercial sensors are packaged, and explain what you need to know to purchase them on a web site.
• Sensor Development Kit and Prototyping
• In module 2 you will learn how to design a complete temperature sensor system within a development kit environment. We will teach you how to assign internal components to the schematic. This includes pins, amplifiers, MUX’s, DAC’s, and ADC’s. Then you will learn how to wire in external parts: resistors, thermistors in particular, to the kit. Finally, you will take a deep dive into interfacing a thermistor and associated front end components to the development kit. This includes lessons on using the schematic portion of the kit, as well as writing application software in c code.
• Rotary and Flow Sensors
• In module 3 you will learn how rotary sensors work and how to specify them for purchase. In our videos rotary sensors include both optical encoders and resolvers. You will also learn the design intricacies of flow sensors, along with their appropriate applications. The videos will discuss variable area, differential pressure, vortex, ultrasonic, turbine, thermal mass flow, and coriolis flow meters.
• Amplifiers and Sensor Noise
• In module 4 you will learn the theory and practical application of amplifiers and circuit noise. You will review how gain is calculated in inverting, non-inverting, summing, differential, and instrumentation amplifiers. We will then contrast theoretical vs. real-world amplifier performance, and give examples of how commercial chips specs are interpreted. Then we will discuss the causes of noise in sensor circuits, how the noise affects sensor accuracy, and some steps you can take to reduce noise in your sensor circuit designs.
• Course Project
• This module contains the materials you need to complete the thermistor lab assignment.