book

Embedded Software for the IoT

by Klaus Elk

December 2018

Intermediate to advanced

294 pages

8h 26m

English

De Gruyter

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1.1 The tale of the internet1.2 The cloud1.3 Internet of things1.4 IoT related terms
2.1 No OS and strictly polling2.2 Co-routines 2.3 Interrupts2.4 A small real-time kernel2.5 A nonpreemptive operating system2.6 Full OS2.7 Open source, GNU licensing, and Linux2.8 OS constructs2.9 Further reading
3.1 Overview3.2 CPU core3.3 CPU architecture3.4 Word size3.5 MMU-memory managed unit3.6 RAM3.7 Cache3.8 EEPROM and flash3.9 FPU-floating point unit3.10 DSP 3.11 Crypto engine3.12 Upgrade path3.13 Second sources3.14 Price3.15 Export control3.16 RoHS-compliance3.17 Evaluation boards3.18 Tool-chain3.19 Benchmarking3.20 Power consumption3.21 JTAG debugger3.22 Peripherals3.23 Make or buy3.24 Further reading

4.1 Design for performance4.2 The fear of the white paper4.3 Layers4.4 Not just APIs—more files4.5 Object model (containment hierarchy)4.6 Case: CANOpen4.7 Message passing4.8 Middleware 4.9 Case: architectural reuse in LAN-XI4.10 Understanding C 4.11 Further reading
5.1 Simulator5.2 ICE – in-circuit emulator5.3 Background or JTAG debugger5.4 Target stand-in5.5 Debugger5.6 strace 5.7 Debugging without special tools5.8 Monitoring messages5.9 Test traffic5.10 Further reading
6.1 Poor man’s backup6.2 Version control—and git6.2.1 GitHub and other cloud solutions6.3 Build and virtualization 6.4 Static code analysis6.5 Inspections6.6 Tracking defects and features6.7 Whiteboard6.8 Documentation6.9 Yocto 6.10 OpenWRT6.11 Further reading
7.1 Introduction to the internet protocols7.2 Cerf and Kahn-internet as net of nets7.3 Life of a packet7.4 Life before the packet7.5 Getting an IP address7.6 DHCP 7.7 Network masks, CIDR, and special ranges7.8 Reserved IP ranges7.9 NAT 7.10 DNS 7.11 Introducing HTTP7.12 REST7.13 TCP sockets on IPv4 under Windows7.14 IP fragmentation7.15 Introducing IPv6 addresses7.16 TCP Sockets on IPv6 under Linux7.17 Data transmission7.18 UDP sockets7.19 Case: UDP on IPv67.20 Application layer protocols7.21 Alternatives to the socket API 7.22 Ethernet cabling7.23 Physical layer problems7.24 Further reading
8.1 Finding the IP address8.2 The switch as a tool8.2.1 Mirroring8.2.2 Statistics8.2.3 Simulating lost frames8.2.4 Pause frames8.3 Tap8.4 SNMP 8.5 Wireshark 8.6 Network commands8.7 Further reading
9.1 Introduction9.2 Wi-Fi basics9.3 The access point as a repeater9.4 How is speed calculated?9.5 Case: Wi-Fi data transmission9.6 Case: beacons9.7 Case: a strange lagging9.8 Aggregated frames9.9 Channel assessment9.10 Bluetooth low energy9.11 Certification9.12 Further reading
10.1 Introduction10.2 The goals of a hacker10.3 Network security concepts10.4 Hash function10.5 Symmetric key encryption10.6 Case: enigma10.7 Asymmetric key encryption10.8 Digital signature10.9 Certificates10.10 Message authentication code10.11 Nonce10.12 Secure socket communication10.13 OpenSSL 10.14 Case: heartbleed 10.15 Case: Wi-Fi security10.16 Software Crypto libraries10.17 Trusted platform module10.18 Embedded systems10.19 Vulnerabilities in embedded systems10.20 Export control10.21 Further reading
11.1 Why digital?11.2 Why filters?11.3 About the sampling frequency11.4 Time and frequency domains11.5 Analog and digital definitions11.6 More duality11.7 A well-behaving system11.8 IIR filter basics11.9 Implementing IIR 11.10 FIR filter basics11.11 Implementing FIR11.12 Dynamic range versus precision11.13 Integers11.14 Fixed-point arithmetic11.15 Q-notation and multiplication11.16 Division11.17 BCD11.18 Further reading
12.1 Introduction12.2 Important terms12.3 Control charts12.4 Finding the control limits12.5 Subgroups12.6 Case: insulation plates12.7 EWMA control charts12.8 Process capability index12.9 Further reading

Content preview from Embedded Software for the IoT

8Network tools

8.1Finding the IP address

In Section 7.5, we discussed how a device gets an IP address. But how do we know what it is? This is a common problem when working with TCP/IP based devices. Normally, you know which TCP port you want to address, but what is the IP address?

A very common strategy is to give up on finding the IP address, and instead simply set it to its default. Many devices have a reset button of some kind, and a label specifying the default IP address and mask. The default is typically a static address like, for example, 192.168.1.1 with mask 255.255.255.0. In other words, an address in a private range in a /24 network. After resetting to this default, you configure an Ethernet port on your PC to, for example, 192.168.1.2 ...