Custom Raspberry Pi Interfaces : Design and Build Hardware Interfaces for the Raspberry Pi

Design and build custom hardware interfaces for the Raspberry Pi and discover low cost display and sensor options for embedded system projects. With this book you'll master 12C communications using Raspbian Linux in C and perform ADC and DAC experiments. You'll experiment with debounce buttons and switches using hardware and software solutions. Develop flywheel rotary encoder effects for ease of tuning and construct a hardware interface to the Music Playing Daemon (MPD) with developed software. Discover how to add your own hardware keypad for remote combination lock applications. Custom Raspberry Pi Interfaces offers a thorough chapter on interfacing 5-volt systems to 3.3-volt Raspberry Pis designed to expand your choice of peripheral options. Ready to go C programs involving GPIO and I2C peripherals are provided. This book also explores ADC, DAC, rotary encoders, CMOS shift registers. I2C I/O extenders. What you'll learn: Build simple, low cost input/output interfaces including rotary encoders Interface with 5-volt devices from a 3-volt Raspberry Pi system Apply analog to digital and digital to analog conversions on the Pi Read potentiometers (volume control) from the Pi Determine step, directions, and velocity of a rotary encoder Perform remote interfacing using the I2 PCF8574 chip Work with external CMOS devices like the 74HC595 (in C ) Who this book is for: Students and hobbyists interested in building custom interfaces for their Raspberry Pis. Contents at a Glance......Page 4 Contents......Page 5 About the Author......Page 13 About the Technical Reviewer......Page 14 Chapter 1: Introduction......Page 15 What to Purchase......Page 16 Let’s Begin......Page 18 Chapter 2: 3V/5V Signal Interfacing......Page 19 7400 Series (TTL)......Page 20 3.3V Logic......Page 21 Voltage Dividers......Page 23 7400 Series Derivative Families......Page 25 Converting 5V to 3V Input: 74LVC245......Page 26 Converting 5V to 3V Input: 74LVC244......Page 28 Input Protection Diodes......Page 30 Converting 3 Volts to 5 Volts with the HCT Family......Page 33 74HCT245......Page 34 Switching Speed......Page 36 Summary......Page 37 Bibliography......Page 38 VGA Converters......Page 39 Resolution and Refresh Rates......Page 40 /boot/config.txt......Page 41 Summary......Page 47 Bibliography......Page 48 LCD Module 1602A......Page 49 I2C Serial Interface......Page 50 I2C Module Configuration......Page 51 I2C Module Output......Page 52 I2C Module Input......Page 55 3 Volts to 5 Volts......Page 56 Attaching the I2C Serial Module......Page 58 Displaying Data......Page 60 Reading from the LCD1602......Page 62 Class LCD1602......Page 65 I2C Baud Rate......Page 66 Profit and Loss......Page 67 Summary......Page 68 Chapter 5: MC14490 and Software Debouncing......Page 69 Hardware: MC14490......Page 70 Capacitor C1......Page 71 Experiment......Page 72 More Inputs......Page 75 Software Debouncing......Page 76 Experiment......Page 78 Summary......Page 80 The YL-40 PCB......Page 81 DAC (AOUT)......Page 84 Removing YL-40 LED D1......Page 87 Hacking YL-40 I2C Address......Page 88 I2C Bus Setup......Page 89 Experiment......Page 90 Experiment......Page 91 Experiment......Page 92 Extending Voltage Range......Page 93 Repairing the Temp Sensor......Page 94 Conversion to Celsius......Page 97 Experiment......Page 98 1N914 Experiment......Page 99 Software......Page 103 Bibliography......Page 104 Potentiometers......Page 105 Voltage Dividers......Page 107 Pot Resistance......Page 109 Effect of ADC Bits......Page 110 Experiment......Page 111 Applying Potentiometer Controls......Page 113 Summary......Page 115 Bibliography......Page 116 Keyes KY-040 Rotary Encoder......Page 117 The Switch......Page 119 Operation......Page 121 Evaluation Circuit......Page 122 Interfacing to the Pi......Page 124 Experiment......Page 126 Experiment......Page 127 Sequence Errors......Page 128 FM Dial 1......Page 129 FM Dial 2......Page 131 Class Switch......Page 133 Main Routine......Page 140 Bibliography......Page 141 74HC165 Pinout......Page 142 Function Table......Page 144 Breadboard Experiment......Page 145 Program......Page 147 Logic Analyzer View......Page 149 Profit and Loss......Page 150 Even More Inputs......Page 151 Combining GPIOs......Page 152 Summary......Page 153 74HC165 Pinout......Page 154 Function Table......Page 155 Breadboard Experiment......Page 156 Experiment Run......Page 159 Input and Output......Page 161 Additional Outputs......Page 164 Summary......Page 165 MCP23017......Page 166 Wiring......Page 168 Output GPIO Experiment......Page 170 Input Experiment......Page 171 Software Operations......Page 172 I2C Header Files......Page 173 I2C Write......Page 174 I2C Read......Page 175 Configuration......Page 176 Interrupt Capability......Page 177 Summary......Page 181 Audio Preparation......Page 182 MPD/MPD......Page 184 Hardware Setup......Page 187 Test Volume Control......Page 188 The mpcctl Program......Page 189 Main Program......Page 190 Rotary Encoder Thread......Page 194 LCD Thread......Page 198 MPC Status Thread......Page 200 Volume Control Thread......Page 201 Program Summary......Page 202 Bibliography......Page 203 Breadboard Setup......Page 204 Input Tests......Page 206 High-Side Driver......Page 207 Driving an LED......Page 208 The Keypad......Page 209 Keypad Program......Page 214 The main Program......Page 215 The key_lookup Function......Page 217 The i2c_write Function......Page 218 The i2c_read Function......Page 219 Combination Lock......Page 220 Combination Lock......Page 221 The main Program......Page 222 The get_key_code Function......Page 224 Bibliography......Page 225 Index......Page 226 Design and build custom hardware interfaces for the Raspberry Pi and discover low cost display and sensor options for embedded system projects.With this book you'll master 12C communications using Raspbian Linux in C++ and perform ADC and DAC experiments. You'll experiment with debounce buttons and switches using hardware and software solutions. Develop flywheel rotary encoder effects for ease of tuning and construct a hardware interface to the Music Playing Daemon (MPD) with developed software. Discover how to add your own hardware keypad for remote combination lock applications.__Custom Raspberry Pi Interfaces__**What you'll learn:**Build simple, low cost input/output interfaces including rotary encodersInterface with 5-volt devices from a 3-volt Raspberry Pi systemApply analog to digital and digital to analog conversions on the PiRead potentiometers (volume control) from the PiDetermine step, directions, and velocity of a rotary encoderPerform remote interfacing using the I2 PCF8574 chipWork with external CMOS devices like the 74HC595 (in C++)**Who this book is for:** This book equips the reader with skills necessary to design and build custom hardware interfaces for the Raspberry Pi. A thorough chapter on interfacing 5-volt systems to 3.3-volt Raspberry Pis expands the reader?s choice of peripheral options. Ready to go C++ programs involving GPIO and I2C peripherals are provided. Explores ADC, DAC, rotary encoders, CMOS shift registers. I2C I/O extenders. Readers will discover low cost display and sensor options for embedded system projects. Master 12C communications using Raspbian Linux in C++. Perform ADC and DAC experiments. Debounce buttons and switches using hardware and software solutions. Read rotary encoders for direction and step. Develop flywheel rotary encoder effects for ease of tuning. Construct a hardware interface to the Music Playing Daemon (MPD) with developed software. Discover how to add your own hardware keypad for remote combination lock applications This Book Equips The Reader With Skills Necessary To Design And Build Custom Hardware Interfaces To Be Used By The Raspberry Pi. A Thorough Chapter On Interfacing 5-volt Systems From A 3.3-volt Raspberry Pi System Equips The Reader For Additional Peripheral Options. Ready To Go C++ Programs Involving I2c And Spi Peripherals Are Supplies. Explores Adc, Dac, Rotary Encoders, And Gpio. Readers Will Discover Low Cost Display And Sensor Options For Embedded System Projects. Master I2c And Spi Communications From Raspbian Linux In C++. Perform Adc And Dac Experiments On Their Pis. Debounce Hardware And Software Buttons/switches. Read Rotary Encoders For Direction And Step In C++. Implement Flywheel Rotary Encoder Effects For Use In Tuning Gnuradio. And Hack Gnuradio Software So It Will Respond To Their Custom Hardware Controls.