3.9 KiB
Things Gateway by Mozilla
Build Your Own Web of Things Gateway. The "Web of Things" (WoT) is the idea of taking the lessons learned from the World Wide Web and applying them to IoT. It's about creating a decentralized Internet of Things by giving Things URLs on the web to make them linkable and discoverable, and defining a standard data model and APIs to make them interoperable.
Getting Started
These instructions will get you a copy of OpenWrt's build system on your local machine for development and testing purposes. To check the prerequisites for your system check out this link.
git clone https://github.com/openwrt/openwrt
cd openwrt
Configure the build system
We need to configure the build system and select the Things Gateway package. This process is no different from selecting other OpenWrt packages. For this example we will be using build configuration for Raspberry Pi 2/3.
Update feeds and open menuconfig interface:
make package/symlinks
make menuconfig
Select your target:
Target System (Broadcom BCM27xx) --->
Subtarget (BCM2709/BCM2710 32 bit based boards) --->
Target Profile (Raspberry Pi 2B/3B/3B+/3CM) --->
Things Gateway package is a bit beefy. In order to fit the image, extend the filesystem size from 256 to 1024 MB:
Target Images --->
(1024) Root filesystem partition size (in MB)
Select Things Gateway package:
Languages --->
Node.js --->
<*> node-mozilla-iot-gateway
Save and exit.
Building the image
Run the build process and substitute with the number of your CPU cores:
make -j<N>
Flashing on the SD card
Process of flashing the image will depend on which device you have. Instructions below are for Raspberry Pi 2/3. For other devices consult OpenWrt wiki pages. Be careful to replace the X in the third command with the drive letter of your SD card.
cd bin/targets/brcm2708/bcm2709
gunzip openwrt-brcm2708-bcm2709-rpi-2-ext4-factory.img.gz
sudo dd if=openwrt-brcm2708-bcm2709-rpi-2-ext4-factory.img of=/dev/sdX conv=fsync
Running Things Gateway from USB flash drive
In case the device doesn't have enough internal storage space, it is possible to run Things Gateway of a USB flash drive. This requires USB flash drive with ext4 filesystem plugged in the device.
Configuration
Do all steps from "Configure the build system" above, and after that change node-mozilla-iot-gateway selection from "*" to "M". This will build the package and all of it's dependencies but it will not install Things Gateway.
Languages --->
Node.js --->
<M> node-mozilla-iot-gateway
Prepare the device
We need to auto mount the USB flash drive in order for the gateway to start at boot. To do so, open a console on your embedded device and create a /etc/fstab file with the following contents. This assumes your USB flash drive is /dev/sda1:
/dev/sda1 /opt ext4 rw,relatime,data=ordered 0 1
/opt/root /root none defaults,bind 0 0
Add "mount -a" to the end of the "boot" function in /etc/init.d/boot
boot() {
.
.
.
/bin/config_generate
uci_apply_defaults
# temporary hack until configd exists
/sbin/reload_config
# Added by us
mount -a
}
Install Things Gateway package
After successfully mounting the USB drive, transfer the .ipk file from your local machine to the device and install it. Note that your package version might defer. Also note that location of .ipk file depends on the selected target, but it will be within ./bin/packages directory. We need to use "--force-space" or else opkg might complain about insufficient space.
On your local machine:
cd bin/packages/arm_cortex-a9_vfpv3/packages/
scp node-mozilla-iot-gateway_0.6.0-1_arm_cortex-a9_vfpv3.ipk root@192.168.1.1:/tmp
On the device:
opkg --force-space install /tmp/node-mozilla-iot-gateway_0.6.0-1_arm_cortex-a9_vfpv3.ipk
Things Gateway should now start at every boot.