Oak Desk with Embedded TV/Monitor part 2

This is a continuation of my build of an oak and glass desk with a 32" TV & computer built into it. The first part of the build is here.

Step 3: Routing the back to fit the TV

Even with the plastic bezel removed from around the front of the TV, there's still a metal frame supporting the screen, which can't be removed.

Just sitting the TV against the back of the desktop would leave a gap of 28mm between the glass and the screen, which is enough to look a bit weird.

I routed the back of the desk to allow the TV to be positioned closer to the glass. This meant removing another 10mm from the desktop thickness, leaving the 'ledge' that the glass sits of at 18mm.

Step 4: Creating the legs

It made sense to use the section that had been removed from the middle of the desktop for the legs. However, I didn't want to just use the flat board, as it would just look lazy and reminiscent of flat-pack furniture, even when cut into 4 for the legs.

I also needed to give consideration to the cabling for the screen, which led me to the idea of splitting the wood into 8 pieces, and pairing them together to create the four legs. This would allow for the cabling to be integrated, and give a more solid leg aesthetic which better suited the style I was aiming for.

The 8 leg parts, ready to pair up and join

The wood cut from the centre of the desk, cut to 8 pieces and joined by dowel and wood glue in pairs to create the four legs #DIY #woodworking #oak #doityourself #carpentry #woodwork #handmade

A photo posted by Anthony (@darkmidnight_diy) on Aug 20, 2016 at 12:29pm PDT

To allow for the cable to be run, before joining the last leg, I routed a groove in the joining sides. a hole was drilled through to the outer corner of the leg. This will be tidied up later to incorporate the hole in part of the design so it doesn't look too out of place.

A photo posted by Anthony (@darkmidnight_diy) on Aug 21, 2016 at 3:07pm PDT

Then the corners of the legs were shaped, and open mortises were cut to attach the desks skirt

A photo posted by Anthony (@darkmidnight_diy) on Aug 23, 2016 at 4:55am PDT

A photo posted by Anthony (@darkmidnight_diy) on Aug 27, 2016 at 10:44am PDT

A photo posted by Anthony (@darkmidnight_diy) on Sep 2, 2016 at 4:43am PDT

With the legs done, I can move onto fitting the TV.

Oak Desk with Embedded TV/Monitor

I've been after a new desk for a while, but never really been able to find one that fits the right combination of size, style and budget.

So I decided to build one myself, taking inspiration from a few videogames, where desks with built-in screens are commonplace:

In Splinter Cell: Blacklist (2013), the 'SMI' as it was known, was interactive and and provided a means of displaying menu systems to the player.

More recently, in Doom (2016), the desk is merely part of the scenery.

The plan
As much as I like the look of the tables in the games, I decided to go with a more traditional look.

The TV (red) will be sunk into the table, with the electronics hidden by the apron (grey) part.	When the glass (blue) is added, it will line up with the table surface, creating a flush finish.
The underside - I envisage a frame, possibly a re-purposed wall mount (yellow/gray), supporting the TV. The pink block indicates where I will mount the computer.

I started with a block of oak kitchen counter top. The aim was to put the TV into the desk, then protect it with a glass worktop sunk into the wood.

Step 1: Routing the ledge for the glass

A photo posted by Anthony (@darkmidnight_diy) on Aug 3, 2016 at 3:12pm PDT

The counter-top is 38mm thick, and has substantial weight to it. The plan was to route 10mm deep into it so that the glass would sit flush with the rest of the wood.

The glass was centered on the table and marked up. I'd only be routing the ledge, I'd be cutting the middle part out entirely, to make room for the screen, so it didn't make sense to rout all that.


I also left the corners - once the middle was removed I'd use a forstner drill to do those, to ensure a nice round corner.


Step 2: Cutting out the middle

A photo posted by Anthony (@darkmidnight_diy) on Aug 7, 2016 at 10:01am PDT

It would be a shame to waste the large chunk of wood from the middle, so I thought I'd use it to create the legs which meant I had to remove it intact.

I did this by using a circular saw to plunge-cut on each side, using the routed ledge as a guide, then using a jigsaw to finish the cuts on each side, allowing the middle to drop out (which of course had to be controlled, leaving it unsupported would likely have caused the wood to split when the majority of support was gone).


With the middle removed, I could finish the corners of the ledge using the forstner drill.

After a lot of planing and sanding, the glass finally fit. #woodworking #DIY A photo posted by Anthony (@darkmidnight_diy) on Aug 9, 2016 at 5:12am PDT

The next steps are to build the legs and mount the TV.

HD44780 LCD to Raspberry Pi

My interest in electronics initially started as a result of PC modding back in the late 90s/early 2000s. Back then, most desktop computers were typical beige boxes - it was all about the internal hardware, not the design of the system itself, and it fell to the users to make then any more interesting than that.

A common mod was to install a LCD screen into the front of the desktop to display things such as system stats (CPU, Memory, temperature), notifications (Email/MSN/ICQ!) or the currently playing track on Winamp.

My old desktop PC has long since been retired, but I still have the LCD that I used, and now I've found an excuse to use it again.

Nostalgia aside, I have a project underway that is going to require a headless Raspberry Pi. While it's easy enough to SSH into the Pi and get to a terminal from another computer, it would also be handy to have at-a-glance stats available.

Fortunately, there's a way to connect a HD44780 LCD (standard text one like mine) to the Pi, using the standard GPIO pins, and leaving the serial pins free (which I'll need for another part of the project).

The thing to be wary of when looking for instructions on connecting one of these displays to a Raspberry Pi is that there are many 'LCD backpacks' and specially designed accessories out there. I'm not using any of those, simply the Pi, the LCD, and a potentiometer to adjust contrast on the display.

Adafruits wiring guide is a good start. While it's aimed at 16x2 displays, it does apply to those of other sizes (the one I'm using is 4x20. They keep referencing their 'Pi Cobbler', though this is simply a breakout board they sell, and it's easy enough to map to the standard Pi pins.
 
A couple of points worth reiterating - the GPIO pins are designed for 3.3v operation, but the LCD for 5v. To avoid 5v being sent to the GPIO, connect the RW pin of the LCD to ground. Also worth noting is the difference between LED and EL backlight. EL has a higher current draw, so trying to power it from the Pi might overload it (LED however is fine). The displays can operate just fine without the backlight, so it's optional anyway. Mine is EL, but I don't really need it, so just left it unconnected.

I was relieved to see that LCDproc is still around. This was the software I used back with my old desktop, so I chose to stick with this instead of the Python solution Adafruit suggest. The pins that they recommend using are slightly different, but can be adjusted in the LCDproc config.

• To install LCDproc on the Pi, run
• sudo apt-get install lcdproc
• Open the config file
• sudo nano /etc/LCDd.conf 
• find the line
• Driver=curses
• and replace with
• Driver=hd44780 
• Find (Ctrl+W) the [hd44780] section and change the ConnectionType line to
• ConnectionType=rpi 
• Underneath add the pin mappings in the format shown below 

D7=18
D6=23
D5=24
D4=25
EN=8
RS=7 
 
Even though there is a driver file (hd44780.so) in the driver path, it doesn't seem to work.
Some Google searching found someone else with a similar issue and a replacement driver file, see steps 4 through 10 on there. (though note there's some differences in the rest of their setup to mine, so beware.)

Once that's done, restart LCDd with

• sudo service LCDd restart

and you should see some text on your LCD!

The default LCDProc screen - the ribbon cable at top left connects to the Pi GPIO.
The small PCB in the top right is a 3.3v to 5v level converter that is to be used for a different project.