Adding LEDs to Edison to report on battery and server status

First we need to deactivate the Buendia Server to connect to LAN internet. This is covered in more detail here. To do this connect to the Edison using screen, as documented in setup. You'll find yourself in Yocto (NB. not the jailed Debian OS that Buendia runs on and is accessible via e.g. chroot /home/root/debian/ /bin/bash or directly via ssh; screen is recommended here as ssh will be disrupted). Run the next 4 lines together:

echo "NETWORKING_AP=0
NETWORKING_DHCP_DNS_SERVER=0
NETWORKING_SSID=your_network_id
NETWORKING_PASSWORD=your_network_pwd" > /home/root/debian/usr/share/buendia/site/99-local

reboot

When you're back up, test the internet with

curl icanhazip.com

GPIO Setup

GPIO appears to only work from Yocto. Yocto comes pre-installed with the necessary GPIO libraries, but does require an update. Yocto's package manager (equivalent of apt-get) is opkg, and work's in pretty much the same way.

opkg update
opkg install libmraa0

mkdir /home/root/gpio
cd /home/root/gpio

Now let's test the GPIO. Run the following 13 lines together:

echo "import mraa
import time

# Setup
x = mraa.Gpio(31)
x.dir(mraa.DIR_OUT)

# Loop
while True:
    x.write(1)
    time.sleep(0.5)
    x.write(0)
    time.sleep(0.5)" > blink.py

Connect an LED to your Edison's GPIO Block - high to the GP44 pin, low to GND Make sure you add a resistor (e.g. 1k) in series to protect the LED.

python blink.py

You should now be blinking.

Buendia server status LED

For this we'll use the following pins to control an RGB LED. Note they're labelled differently on the GPIO block to the code:

Label on GPIO Block	pin # in code	RGB LED pin
GP44	31	red
GP45	45	green
GP46	32	blue

Setup working folders

mkdir /home/root/debian/home/buendia
mkdir /home/root/debian/home/buendia/sd
cd /home/root/debian/home/buendia

Mount SD card

Append a line to debian's /etc/rc.local file (before 'exit') to mount the SD at /home/buendia/sd on startup

chroot /home/root/debian perl -0777 -i -pe 's/^exit 0/# mount SD card\nmount \/dev\/mmcblk1p1 \/home\/buendia\/sd\/ &\n\nexit 0/igm' /etc/rc.local

Check it looks right - should see mount /dev/mmcblk1p1 /home/buendia/sd/ & above exit 0

tail /home/root/debian/etc/rc.local

Symbolic folder from Yocto to debian SD card folder

ln -s /home/root/debian/home/buendia/sd /home/root/gpio/sd

Get the server-reporting Python script

chroot /home/root/debian git clone https://github.com/geotheory/buendia_server_status
cp buendia_server_status/server_status.py /home/root/gpio
chmod 755 /home/root/gpio/server_status.py

Now we'll configure the Python script to run on startup. This means creating a .sh file that will call it, and telling Yocto to execute at startup.

mkdir /etc/init.d
cd /etc/init.d

echo "#!/bin/sh
python /home/root/gpio/server_status.py >> /home/root/gpio/sd/log.txt 2>&1" > server_status.sh

chmod 755 server_status.sh

Add script to update-rc.d daemon

update-rc.d server_status.sh defaults 99

Battery status LED

For an LED to report on battery level you'll need to purchase the SparkFun LiPo Fuel Gauge.

We'll use the following pins to control an RGB LED. Note again they're labelled differently on the GPIO block to the code:

Label on GPIO Block	pin # in code	RGB LED pin
GP131	35	red
GP130	26	green
GP129	25	blue

[WORK IN PROGRESS..]

Reinstating the Buendia server

Setup is now complete. Connect LED's to the GPIO as per the table above. Then revert the system to server mode:

rm /home/root/debian/usr/share/buendia/site/99-local
reboot

You should now see the LED's flicker to test, and then begin reporting server status