Digital Electronics, Software and Hardware K. A. Connor Mobile Studio Project Center for Mobile Hands-On STEM LESA Engineering Research Center ECSE Department Rensselaer Polytechnic Institute

Outline Digital Static I/O with Analog Discovery Photocell Light Sensor Circuit TTL Gates PWM from Digital Output

Static I/O 16 Channels Configuration Right Click Channel Input Output Right Click Channel LED for Output Switch for Input Config – Bit I/O

Photocell Sensor A Photocell is a resistor whose value reduces with increasing light levels Photocell Voltage Divider Fixed R Meas. Photocell Meas. Fixed Resistor chosen to achieve maximum range of measured voltages. Very common sensor for Arduinos and other processors

TTL Gates Transistor–transistor logic (TTL) is a class of digital circuits built from bipolar junction transistors (BJT) and resistors. TTL NAND Gate Truth Table Experiment

PWM from Digital Output Previously used PWM from Analog Discovery function generator (W1 or W2) All 16 Digital I/O Channels can also provide a PWM signal Many more channels and Can be controlled by and a key part of a fully digital system and, thus, generally more flexibly, if not necessarily more easily, programmed.

Functional Blocks Generic Circuit System Source Transfer Function Load Generic Circuit System Source (voltage plus resistance, as in Thevenin Equivalent) Intermediate Circuit (characterized by a transfer function … filter, amplifier, etc.) Load (resistance, capacitance, inductance or combination) Voltage divider for Zin and Zout

Adding Functional Blocks Adding Functional Blocks to a Circuit can Radically Change What the Circuit Does Potential Issues Check input and output impedances to be sure independent functions work together Check input and output voltage, current, power to be sure that they are adequate Voltage Divider Video 6.1 (Designing Circuits from Functional Blocks)

Ready for Next Experiment All systems in place Sensor (Photocell) Processor (Analog Discovery) Actuator (LED) Model for other systems