colorpicker-client

A socket.io 1.2 client that connects to a colorpicker-server socket.io server.

Its main purpose is to convert an array of JSON RGB objects like [{ r: 100, g: 50, b: 0 }, { r: 100, g: 50, b: 0 } into a UART instruction like '345,5,1,100,50,0;2,100,50,0,3,000,000,000,4,000,000,000,5,000,000,000;', and pipe it over UART to /dev/ttyO1.

Getting Started

You'll need a colorpicker-server instance running before this client is useful. You can deploy this server to a free host like Heroku or Nodejitsu, or test locally.

# set up the GUI and server
git clone git@github.com:Lordnibbler/colorpicker-server.git
cd colorpicker-server
npm install -d
npm start

# set up the client
git clone git@github.com:Lordnibbler/colorpicker-client.git
cd colorpicker-client
npm install
npm start

You should see a connected to socket at http://127.0.0.1:1337 message.

Browse to http://localhost:1337 to use the GUI.

Configuring a Beaglebone Black with Angstrom Distro

You'll need to do three things:

1. upgrade Node.js
2. configure systemctl to set up reliable network connectivity at boot
3. configure systemctl to start colorpicker-beaglebone Node service at boot

1. Upgrade Node.js

I refer you to the wonderful instructions at speakinbytes.com. I recommend the current stable version of node, currently 0.10.32. You'll need at LEAST 0.10.0.

2. Network Connectivity

My findings have been that connman is very unreliable, so I fell back to using /etc/network/interfaces. To disable connman:

systemctl disable connman.service

# double check
systemctl status connman.service

Edit /etc/network/interfaces with your editor of choice. For ethernet/hardwired internet connectivity the only logic you need here is the loopback and the eth0 configuration, but there's also some example wifi, USB, and bluetooth configs here:

# /etc/network/interfaces
# configuration file for ifup(8), ifdown(8)

# The loopback interface
auto lo
iface lo inet loopback

# Wireless interfaces
 iface wlan0 inet dhcp
	wireless_mode managed
	wireless_essid any
	wpa-driver wext
	wpa-conf /etc/wpa_supplicant.conf

 iface atml0 inet dhcp

# Wired or wireless interfaces
auto eth0
iface eth0 inet dhcp

# Ethernet/RNDIS gadget (g_ether)
# ... or on host side, usbnet and random hwaddr
iface usb0 inet static
	address 192.168.7.2
	netmask 255.255.255.0
	network 192.168.7.0
	gateway 192.168.7.1

# Bluetooth networking
iface bnep0 inet dhcp

If you want additional help setting up WiFi, this article is handy.

After setting up your interfaces, configure a systemctl service to start ethernet connectivity at boot, touch a new file located at /etc/systemd/system/net.service:

# /etc/systemd/system/net.service
[Unit]
Description=Network interfaces
Wants=network.target
Before=network.target
BindsTo=sys-subsystem-net-devices-eth0.device
After=sys-subsystem-net-devices-eth0.device

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/sh -c "sleep 5; ifup eth0"
ExecStop=/bin/sh -c "ifdown eth0"

[Install]
WantedBy=multi-user.target

Then enable the service!

systemctl enable net.service

# double check
systemctl start net.service
systemctl status net.service

You can check your connectivity using ifconfig.

3. Starting colorpicker-beaglebone at boot

To start this Beaglebone colorpicker client at boot, you can follow a similar approach to the network connectivity service. I have provided an example in the /angstrom directory of this repository.

First, touch a new file at /lib/systemd/system/colorpickerbeaglebone.service (ensure your paths are correct, these are an example):

# /lib/systemd/system/colorpickerbeaglebone.service
[Unit]
Description=colorpicker-beaglebone automatic start

[Service]
WorkingDirectory=/home/root/colorpicker-beaglebone/angstrom
ExecStart=/home/root/colorpicker-beaglebone/angstrom/colorpickerbeaglebone.sh

[Install]
WantedBy=multi-user.target

You can copy the contents of /angstrom/colorpickerbeaglebone.sh from this repo if you intend to use UART + Arduino to power the LEDs.

Then enable the service!

systemctl enable colorpickerbeaglebone.service

# double check
systemctl start colorpickerbeaglebone.service
systemctl status colorpickerbeaglebone.service