Creating a health dashboard by hacking intelligence into an AOpen (the ‘A’ for ancient) monitor; with metrics aggregated by Graphite and beautifully displayed with Grafana.
As promised, let’s dive into some of the modifications made to Audio Control and USB/Ethernet Hub – all part of the master plan.
Audio Control – Moving Audio IN, INside
With our cheap little Mini HDMI to VGA adapter providing audio output from the Pi, all we need to do is feed it into the monitor. Spoon of choice? AUX cable.
Now here’s where it gets a little awkward.
With the unit closed, Audio IN is facing outwards. Meaning we’d have to lead an AUX outside the unit and plug it into the back, making this odd protrusion.
Well, that won’t do.
One of the key tenets of this project was to ensure the unit is compact, with as many components encapsulated within the monitor chassis itself.
Let’s perform a surgery, and extract the Audio IN (AUX) port and see if we can move it around.
And done. Time to test.
Powered on the unit, ensured the AUX cable was connected between our Mini HDMI > VGA adapter and Audio IN on the monitor, and basked in the graininess of Do You Remember remixed by grey.
Yeah, it was pretty bad.
Not because of the mod I assure you (having tested audio on this monitor awhile back), more so because the speakers are terrible.
Anyways, won’t be playing music through this anytime soon – any audio coming through the Pi will be for notifications/alarms.
USB/Ethernet Hub – Mounting
Never thought I’d say it, but for once, this modification was made EASIER by the cheap construction of a part.
The Ethernet/Hub adapter easily came apart (surprise), separating away from its case, allowing me to determine a suitable mounting location.
Deciding to mount it near the bottom for both out-of-sight accessibility came with the added bonus of being closer to the Pi.
To mount the hub, I ran one of the leftover hinge screws through the lower-half of the plastic hub case, right back into the frame.
All that was left was to cut a portion of the rear cover out to accommodate the area now taken by the hub, and we were good to go.
And there we go!
This wraps up a majority of the hardware.
The next post will cover assembly in more detail, along with any issues we should consider before side-mounting onto my server rack.