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Serial ports on the Beaglebone Black

On the BeagleBone Black, it's only the /dev/ttyO0 that is enabled by default, and it is coupled to the serial console. The other serial ports must be enabled before they can be used. To enable the uarts 1,2,4 and/or 5 on the BeagleBone Black, rev A, B and C: Rev A/B: Open the file sudo nano/media/BEAGLEBONE/uEnv.txt Mine is Rev C: So sudo nano  /boot/uboot/uEnv.txt Add the key "capemgr.enable_partno=" Add the ports you want to enable, comma separated (BB-UART1, BB-UART2. BB-UART4, BB-UART5) In my case I want to add tty04 so I can hook up to the RF Transmitter and LCD of my home automation  Reboot An example line looks like this: ubuntu@beaglebone:~$ sudo nano /boot/uboot/uEnv.txt Find a suitable line to edit e.g. ##Disable HDMI cape_disable=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN capemgr.enable_partno=BB-UART4 After reboot, the device is present in the device list: ubuntu@beaglebone:~$ ls -l /dev/ttyO* crw-rw---- 1 root tty     248, 0 Jul  1 20:39 /dev/ttyO0 crw-rw---- 1 root dialout 248, 4 Jul  1 20:39 /dev/ttyO4 The UARTs map to pins and devices like this:  RX  TX  CTS  RTS  Device  Remark  UART0     J1_4  J1_5      /dev/ttyO0 BeagleBone Black only  UART1  P9_26  P9_24  P9_20  P9_19  /dev/ttyO1  UART2  P9_22  P9_21  P8_37  P8_38  /dev/ttyO2  UART3  P9_42  P8_36  P8_34  /dev/ttyO3  TX only  UART4  P9_11  P9_13  P8_35  P8_33  /dev/ttyO4  UART5  P8_38  P8_37  P8_31  P8_32  /dev/ttyO5

Connman is annoying

Connman is the new way of doing networking apparently but why fix what isn't broken. I know the talk about 'what if the network falls' blah blah blah but if the network should fail then I'm up the Swanny anyway. A big minus side to connman is it doesn't work well with my wireless network. I don't need wireless really but I would like to make the whole hub fairly portable (just need mains supply) rather than need a network cable.

I don't want connman anywhere near my beaglebone.

I want this → http://www.unix.com/man-page/Linux/5/interfaces/

How to remove connman and revert to traditional network interface start up.

DISABLE CONNMAN
systemctl disable connman.service

CREATE INTERFACES FILE
cat > /etc/network/interfaces <<EOF
auto lo
iface lo inet loopback
 
auto eth0
iface eth0 inet static
address 192.168.0.99
netmask 255.255.255.0
gateway 192.168.0.1
dns-nameservers 192.168.0.1
 
iface usb0 inet static
address 192.168.7.2
netmask 255.255.255.0
gateway 192.168.7.1
dns-nameservers 192.168.7.1
 
iface wlan0 inet static
address 192.168.0.98
netmask 255.255.255.0
gateway 192.168.0.1
dns-nameservers 192.168.0.1
wireless_mode managed
wireless_essid “SSID NAME HERE”
wpa-driver wext
wpa-conf /etc/wpa_supplicant.conf
pre-up wpa_supplicant -B -Dwext -iwlan0 -c/etc/wpa_supplicant.conf
post-down killall -q wpa_supplicant
EOF

CREATE RESOLV.CONF
cat >/etc/resolv.conf <<EOF
search local
nameserver 192.168.0.1
EOF

CREATE WPA_SUPPLICANT.CONF WITH PASS
cat >/etc/wpa_supplicant.conf <<EOF
ap_scan=2

network={
ssid="VM275247-2G"
proto=WPA RSN
key_mgmt=WPA-PSK
pairwise=CCMP TKIP
group=CCMP TKIP
psk=long key for psk
}
EOF

CREATE SERVICE FOR WIFI
cat >/etc/systemd/system/net.service <<EOF
[Unit]
Description=Network interfaces
Wants=network.target
Before=network.target
BindsTo=sys-subsystem-net-devices-wlan0.device
After=sys-subsystem-net-devices-wlan0.device

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/sh -c "sleep 5;ifup wlan0"
ExecStop=/bin/sh -c "ifdown wlan0"

[Install]
WantedBy=multi-user.target
EOF

START SERVICE
systemctl enable net.service

Obviously you need to enter your own details :)

backing up the BeagleBone Black eMMC

After you have got the BBB up and running how you like it, backing up is always a good idea.

If, like me, you are using it for home automation based on the Livebox, you can of course back up the ini settings, plugboard scripts etc using the web GUI but I like to keep a backup of the entire eMMC.

There are a few methods to be found on the 'net that require the use of a script on a microSD card. This is ideally the best way but requires stopping the BBB (and if SWMBO is expecting things to happen, that's never good)

So here is an option to use dd over ssh to backup to another PC (in my case a mac)

on the BBB

sudo dd if=/dev/mmcblk0 bs=1M | ssh themac@192.168.0.X "dd of=/Users/themac/Desktop/BBB_Backup_date.img bs=1m"

n.b. the block size is set on the BBB using bs=1M but on the mac HAS to be bs=1m (lowercase) (I'm not sure if this is the case :) on a pc)

To restore. This needs to be done after booting from an SD card to free up the eMMC The eMMC is then mmcblk1 not mmcblk0

ssh themac@192.168.0.X "dd of=/Users/themac/Desktop/BBB_Backup_date.img bs=1m” | sudo dd of=/dev/mmcblk1 bs=1M

Then power down, remove the SD card and reboot.