Raspberry Pi Hardware Reference

✍ Scribed by Gay, Warren

• Publisher: Apress
• Year: 2014;2015
• Tongue: English
• Leaves: 234
• Category: Library

✦ Synopsis

The Raspberry Pi is deceptively simple. Plug it in, boot it up, and use it as a personal computer, or attach a million gizmos and modules and invent something new and amazing. Either way, what it can actually do is not simple, and you should know exactly what the Raspberry Pi hardware is all about.Raspberry Pi Hardware Reference, fromMastering the Raspberry Pi, is the hardware guide you need on your desk or workbench.Every detail is covered: from power to memory, from the CPU to working with USB. You'll find all the details about working with both wired and wireless Ethernet, SD cards, and the UART interface. The GPIO chapter is invaluable, covering power budgeting, access, and even small but important details like the correct usage of sudo when working with GPIO pins. You'll also find details about the 1-Wire driver, the I2C bus, and the SPI bus. If you need to know anything about your Raspberry Pi's hardware, you will find it here, inRaspberry Pi Hardware Reference.What you’ll learn How to work with Raspberry Pi power, including adapters and battery requirements Working with header strips and LEDs Working with SDRAM and memory mapping Understanding the CPU Interface details, including USB, UART, and GPIO Who this book is for Raspberry Pi hobbyists who need know all of the details about Raspberry Pi hardware and what Linux files and commands control that hardware.

✦ Table of Contents

Contents at a Glance......Page 3
Contents......Page 221
About the Author......Page 232
About the Technical Reviewer......Page 233
Acknowledgments......Page 234
Introduction......Page 5
Models......Page 7
Hardware in Common......Page 9
Which Model?......Page 10
Calculating Power......Page 11
Current Requirement......Page 12
Model B Input Power......Page 13
Powered USB Hubs......Page 14
An Unsuitable Supply......Page 15
Voltage Test......Page 16
LM7805 Regulation......Page 18
DC-DC Buck Converter......Page 20
Signs of Insufficient Power......Page 22
No Power......Page 23
OK or ACT LED......Page 24
Header P1......Page 25
Safe Mode......Page 27
GPIO Configuration at Reset......Page 28
Header P5......Page 29
Reset......Page 30
PdftkEmptyString......Page 31
MemTotal......Page 33
SwapCached......Page 34
Inactive(anon)......Page 35
SwapTotal......Page 36
Mapped......Page 37
KernelStack......Page 38
WritebackTmp......Page 39
CommitLimit......Page 40
Committed_AS......Page 41
Physical Memory......Page 42
Memory Mapping......Page 44
Length......Page 45
Return Value......Page 46
Final Thoughts on SDRAM......Page 47
Identification......Page 49
Overclocking......Page 50
Execution......Page 52
pthread Error Handling......Page 53
pthread_create(3)......Page 54
pthread_attr_t......Page 56
pthread_detach(3)......Page 58
pthread_kill(3)......Page 59
pthread_mutex_create(3)......Page 60
pthread_mutex_destroy(3)......Page 61
pthread_mutex_unlock(3)......Page 62
Condition Variables......Page 63
pthread_cond_init(3)......Page 64
pthread_cond_wait(3)......Page 65
pthread_cond_signal(3)......Page 66
pthread_cond_broadcast(3)......Page 67
Chapter 6: USB......Page 68
Powered Hubs......Page 69
libusb......Page 70
Include Files......Page 71
Wired Ethernet......Page 74
Changing to Static IP......Page 75
Test Static IP Address......Page 76
Wireless Ethernet......Page 77
Configuration......Page 79
SD Card Interface......Page 83
SD Card Basics......Page 84
Raspbian Block Size......Page 85
Capacities and Performance......Page 86
SPI Bus Mode......Page 87
1-bit SD Mode......Page 88
Wear Leveling......Page 89
RS-232 Converter......Page 91
DTE or DCE......Page 92
RS-232......Page 93
Parity Bit......Page 94
Baud Rate......Page 95
Hardware Flow Control......Page 97
Software Flow Control......Page 98
ARM PL011 UART......Page 99
RTS/CTS Access......Page 100
PL011 UART Features......Page 101
Procedure......Page 102
Serial API......Page 103
struct termios......Page 104
tcgetattr(3)......Page 107
tcsetattr(3)......Page 108
tcdrain(3)......Page 109
tcflow(3)......Page 110
cfmakeraw(3)......Page 111
cfgetospeed(3)......Page 114
cfsetospeed(3)......Page 115
read(2)......Page 116
write(2)......Page 117
readv(2) and writev(2)......Page 118
Error EINTR......Page 120
Pins and Designations......Page 122
Configuration After Reset......Page 123
Configuring Pull-up Resistors......Page 125
Testing Pull-up State......Page 129
Drive Strength......Page 130
Output Pins......Page 132
Driving LEDs......Page 133
Driving Bi-color LEDs......Page 135
Testing Drive Strength......Page 136
GPIO Current Budget......Page 138
Alternate Function Select......Page 139
Alternate Function......Page 140
Sysfs GPIO Access......Page 141
gpioX......Page 142
Chip Level......Page 144
GPIO Tester......Page 145
GPIO Input Test......Page 146
Reading Events......Page 148
Test Run......Page 149
gpio_init()......Page 154
gpio_read()......Page 155
gpio_io.c......Page 156
GPIO Transistor Driver......Page 158
Driver Design......Page 159
Inductive Loads......Page 161
Driver Summary......Page 162
Utility gpio......Page 163
Reading GPIO......Page 164
Modify Drive Levels......Page 165
Line Driving......Page 166
Master and Slave......Page 167
Data I/O......Page 168
Slave Support......Page 169
Reading Temperature......Page 170
Bus Master......Page 172
Slave Devices......Page 173
1-Wire GPIO Pin......Page 175
I2C Overview......Page 176
SDA and SCL......Page 177
Bus Signaling......Page 178
Message Formats......Page 179
Which I2C Bus?......Page 180
Tools......Page 181
Kernel Module Support......Page 182
open(2)......Page 183
ioctl(2,I2C_FUNC)......Page 184
ioctl(2,I2C_RDWR)......Page 185
SPI Basics......Page 188
SPI Mode......Page 189
Signaling......Page 190
Slave Selection......Page 191
Driver Support......Page 192
SPI API......Page 193
SPI Mode Macros......Page 194
Clock Rate......Page 196
Data I/O......Page 197
SPI Testing......Page 200
Appendix A: Glossary......Page 203
Appendix B: Power Standards......Page 209
Power......Page 210
Units......Page 211
Index......Page 212