Notes on Working with IoT Devices
Find IP Address of a Device in the Network without a Monitor
For instance, if you want to find a Raspberry Pi connected to the local network without a connection to a monitor:
sudo nmap -sn 10.244.19.0/24
In the output, you should find it. For instance:
Nmap scan report for 10.244.19.227 Host is up (0.00027s latency). MAC Address: B8:27:EB:82:48:A0 (Raspberry Pi Foundation)
Remember to run it with
sudo to get the platform details. Do NOT repeat it multiple times or for a very large subnet. The system may get blocked in the network because of spamming.
Install Packages on OpenWRT
opkg update && opkg install gcc
Compile a Simple C Code on OpenWRT
gcc -mfloat-abi=hard hello.c -o hello
Determine File Type
For instance, a file which is built for running on Raspberry Pi 1:
ipop-tincan-rpi1: ELF 32-bit LSB executable, ARM, EABI5 version 1 (GNU/Linux), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 2.6.32, BuildID[sha1]=c24056bbd7c9f90660087db2c1296ae3b7dca93b, not stripped
Cross-compile Code for OpenWRT
sudo apt update && sudo apt install ccache libncursesw5-dev
Git on OpenWRT
opkg install git-http opkg install ca-bundle
Expand the Root Partition on OpenWRT
By default, the root partition on the OpenWRT SD card is very small. You can expand it to using “GParted” or other tools on Linux or other operating systems.
Ubuntu 17.10 and CiscoAnyconnect for UF VPN
If you are running Ubuntu 17.10 and fail to install/start Cisco Anyconnect (version 220.127.116.113):
sudo apt install libpangox-1.0-0
Error in Installing Ubuntu or Linux Mint: The grub-efi-amd64-signed package failed to install into /target/.
Create an EFI system Partition before installing the OS.
Add Menu Entry to GRUB
Change GRUB Timeout