This post describes how to setup a BBB with Debian Buster with an image designed for IoT use in the year 2021.In the past we have built embedded systems that use single board computers, like the Raspberry Pi and the Beaglebone Black (BBB), for custom products and prototypes. Recently, we have been trying to build a prototype for a system that would be used for converting a non-internet capable machine to be internet-capable and join the Internet of Things (IoT) space.
Our requirements were to use a low powered device that would be capable of running off a n off the shelf Lithium-ion (Li-ion) battery for at least 4-6 hours. With this in mind we dusted off a set of 3 Beaglebone Black (BBB) boards we have had since 2013. The BBB comes with a 2GB eMMC card on the board, a 10/100 Mbps ethernet PHY chip and connector, a USB-A and USB mini-B connector and 512MB of RAM. It also is capable of booting off a microSD card, which is the method we would be using.
However, the operating system on those BBB boards were so old, we had to catch up on updating it to the latest Debian Buster images that are designed for IoT use. Many years ago, we were compiling our own Angstrom distribution from scratch for the 2GB eMMC chip, but now Debian is capable of running on the BBB so we are switching to that. Debian uses more space than 2GB, so using a 16GB microSD card from SanDisk serves our purpose for this task.
This post describes how to setup a BBB with Debian Buster with an image designed for IoT use in the year 2021. This process can be run on any modern Linux distribution like Debian, Ubuntu, Kali Linux or other equivalents. The system that runs the download, such as your laptop, will be called the host system and the BBB device will be referred to as the target system.
Setting up the Debian Buster image on the microSD card
First download the latest Debian image from here on your host system. We selected the AM3358 Debian 10.3 2020-04-06 4GB SD IoT image.
Verify the SHA-256 sum after the download completes.
Install the package called
xz-utilson the host system, if not already installed. This will have a tool calledxzcatwhich will be used to decompress the image that was downloaded in the earlier step.
Now connect the 16GB or larger microSD card to the host system using an SD-card slot or a USB adapter.
Find the device name of the inserted microSD card by doing an
lsin the/dev/folder or by checkingdmesgand looking at the latest inserted device. It should look like/dev/sdXwhereXrepresents an alphabet betweena-z. In our case it is/dev/sdband we shall be using this device name.Our image size is 4GB and our microSD card is 16GB. So we will write the 4GB image to the microSD card first, use it to boot up the BBB device and then resize the file system using a script provided in the Debian image.
Let’s write the image now to the microSD card using the one-liner below:
$ xzcat bone-debian-10.3-iot-armhf-2020-04-06-4gb.img.xz | sudo dd of=/dev/sdb bs=1M status=progressThis will take anything between 10 to 20 minutes to complete and once it is done pop out the microSD card from the host system.
Insert the microSD card into the BBB device’s microSD card slot and boot the device up using either a USB cable connected to its mini-B USB port, or using a dedicated 5V 2A power adapter. We had a 5V adapter, so we used that.
In case your BBB has an older operating system on the eMMC card, you have to press and hold the USR button, which is near the microSD card slot, then power up the BBB and once the 4 LEDs have lit up you can let go of the button. Now the device will boot up using the microSD card.
Connecting to the BBB
Once the BBB has booted up fully, which should take about 30 seconds or less, you can plug in an ethernet cable into the ethernet port and
sshinto the device. The default image comes withsshenabled. The default username isdebianand password istemppwd.To find the IP address of the BBB, you can check your router DHCP status page and locate the IP address of the device named
beaglebone. You may not need the IP address if you can ping the hostname usingping beagleboneand see if the host system can find the BBB IP address.Or, if you have a HDMI to mini-HDMI cable available you can connect the BBB to a monitor using the cable and then attach a keyboard to the USB A port and directly access the BBB.
Since our goal is to make this BBB IoT capable, we want to access it remotely without adding a keyboard to the actual device.
$ ssh debian@beagleboneThe BBB image comes with USB based internet as well, and that may be a way to access the BBB too. Those IP addresses by default are
192.168.7.2and192.168.6.2. But for this post we will not be using this method. In fact, later in the post we will show how to change these default IP addresses to avoid conflicts in your network if you have several BBB devices connected.
Upgrading the Operating System
Now that you have connected to the BBB via ssh let us upgrade the Debian operating system to get all the latest packages and security updates. But first we resize the disk.
Using
/opt/scripts/tools/grow_partition.shyou can expand the 4GB image on the microSD card to take up the full 16GB space on the card. This script must be run as therootuser or undersudo. This takes about 1 second to complete.$ sudo /opt/scripts/tools/grow_partition.shNow reboot the device by running
sudo reboot.Once the device boots back up again, you should connect back using
sshand be able to rundf -hto see it use the full 16GB disk space in the file system display.Upgrading the packages may kill your existing
sshsession, so run ascreensession first. Then run the following command:$ screen -$ sudo apt-get update && sudo apt-get -y upgrade && sudo apt-get -y dselect-upgrade && rebootBreak out of the
screensession by pressingCtrl A Ctrl Dand wait at least 30-40 minutes for the BBB to fully upgrade the packages.Once the packages have upgraded, the BBB will eventually reboot and be ready to login via
ssh.Follow any other upgrade commands that you may like to do by reading this page. One such command we ran was the kernel upgrade by running the following script and followed by a reboot.
$ sudo /opt/scripts/tools/update_kernel.sh
Disabling Unnecessary Services
The default Debian image comes with certain services that may not be necessary for you and may instead become a security issue. We can check which TCP and UDP network services are running by the following command:
$ sudo netstat -vnatpulOnce you have decided which services you do not need, you can disable them and shut these services down. I have left the
dnsmasqandsshservices running and disabled thenginxandcloud9services.$ sudo systemctl stop cloud9$ sudo systemctl disable cloud9$ sudo systemctl stop nginx$ sudo systemctl disable nginx$ sudo systemctl disable bonescript-autorunIf you plan to run a web-service on the BBB, then do not disable
nginxas you will need it as your reverse proxy.If the eMMC drive is filled with old data that you do not want to use then for safety you should clean up the drive so that the BBB does not accidentally use that drive for booting. This also frees up the eMMC device for acting like
swapspace or for storing a custom boot loader in the future. Usinglsblkfind the correct 2GB device name for the eMMC. It is likely to be/dev/mmcblk1. Then runddon it to clear it up.$ sudo dd if=/dev/zero of=/dev/mmcblk1 bs=1M status=progress
Customizing Hostname, USB network and Login Banners
To change the hostname of the BBB device, edit the
/etc/hostsand/etc/hostnamefile with the new hostname you want to use by replacing every occurrence ofbeaglebonewith your new hostname, saybeaglebone01. Then reboot the device for it to update to the new name.To edit the default login banner change the
/etc/issueand/etc/issue.netfiles. We edited these files to remove the prompt of the default username and password.We highly recommend to change your default password using the
passwdcommand.To change the USB network IP addresses, you have to edit
/etc/default/bb-bootand change the default USB network IP addresses to the appropriate ones for your use case or disable the USB network altogether. Then reboot the system once done.
Setting up WiFi
Sometimes you may be in a situation where your device needs to connect to a WiFi access point and cannot use the ethernet port. In that case you will need a WiFi dongle on the BBB since it does not come with an in-built WiFi chip. The newer Beaglebone boards and the Raspberry Pi boards do come with a WiFi chip. For the BBB, an Edimax USB WiFi dongle is what we have used. Any other USB based WiFi dongle that is supported on Debian will work as well. Insert the WiFi dongle in the USB A port of the BBB device and follow the below steps to set it up.
First locate the wireless device on the system.
$ iwconfigwlan0 IEEE 802.11 ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=20 dBm Retry short limit:7 RTS thr=2347 B Fragment thr:off Encryption key:off Power Management:off
Then get the list of SSIDs this device is able to scan for.
$ iwconfig wlan0 scan | grep -i essidESSID: “mywifi”Let us assume
mywifiis the WiFi network we want to connect to and that it is using WPA2 Personal authentication mode with a password.Let’s encrypt the password correctly and generate a config file that the WiFi daemon
wpa_supplicantcan read successfully. For the purpose of this post, the password for the WiFi ismypassword.$ wpapassphrase “mywifi” "mypassword$" | sudo tee -a /etc/wpa_supplicant/wpa_supplicant.conf$ cat /etc/wpa_supplicant/wpa_supplicant.confnetwork={ ssid="mywifi" #psk="mypassword$" psk=0818b5551fd6aa10c8e1bb454a694e76a89daa119b57bbb8f2fd9dc8ead81829 }Now test if the config file works by running the following command:
$ wpa_supplicant -c /etc/wpa_supplicant/wpa_supplicant.conf -i wlan0 Successfully initialized wpa_supplicant wlan0: SME: Trying to authenticate with f8:c8:29:bb:88:df (SSID='mywifi' freq=2412 MHz) wlan0: Trying to associate with f8:c8:29:bb:88:df (SSID='mywifi' freq=2412 MHz) wlan0: Associated with f8:c8:29:bb:88:df wlan0: CTRL-EVENT-SUBNET-STATUS-UPDATE status=0 wlan0: WPA: Key negotiation completed with f8:c8:29:bb:88:df [PTK=CCMP GTK=CCMP] wlan0: CTRL-EVENT-CONNECTED - Connection to f8:c8:29:bb:88:df completed [id=0 id_str=]Setup the
systemdservice file for the WiFi daemon next.$ cp /lib/systemd/system/wpa_supplicant.service /etc/systemd/system/wpa_supplicant.serviceEdit the file to change the
ExecStartline with the following:ExecStart=/sbin/wpa_supplicant -u -s -c /etc/wpa_supplicant/wpa_supplicant.conf -i wlan0The final file should look like this for example:
[Unit] Description=WPA supplicant Before=network.target After=dbus.service Wants=network.target StartLimitInterval=200 StartLimitBurst=5 [Service] Type=dbus BusName=fi.w1.wpa_supplicant1 ExecStart=/sbin/wpa_supplicant -u -s -c /etc/wpa_supplicant/wpa_supplicant.conf -i wlan0 Restart=always RestartSec=30 [Install] WantedBy=multi-user.targetNow enable the service using
$ systemctl enable wpa_supplicant.serviceKill any pre-running services
$ pkill —QUIT wpa_supplicantRestart the service manually
$ systemctl start wpa_supplicantWait for the service to connect to the WiFi network and check the IP address
$ ifconfig wlan0wlan0: flags=-28605<UP,BROADCAST,RUNNING,MULTICAST,DYNAMIC> mtu 1500 inet 192.168.1.100 netmask 255.255.255.0 broadcast 192.168.1.255 inet6 fe80::76da:38ff:fe70:1be1 prefixlen 64 scopeid 0x20<link> ether 77:dd:33:77:aa:dd txqueuelen 1000 (Ethernet) RX packets 481 bytes 76824 (75.0 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 244 bytes 28439 (27.7 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0Reboot the device to make sure that it connects to WiFi on reboot.
Try connecting to the device using
sshover the WiFI IP address.
Conclusion
With the above steps we have shown how to setup a Beaglebone Black device with the latest image of Debian Buster as of this writing. You can connect the BBB device using WiFi or Ethernet or both. Once the operating system has been setup, the next step would be to write some software that would take advantage of the BBB’s small form factor and the fact that it can be used as an IoT device.
Stay tuned for the next post in this space. If you or your company are interested in retro-fitting a non-internet connected system or machinery with the internet and remotely control it, reach out to us for help, advice and prototyping.