ComputerSphere – converting the knobs to buttons

Before I can mount the motherboard, I needed to return the three knobs back to their original location as I wouldn’t be able to do this with the motherboard in the way.

Originally these knobs were used for volume control, and some form of picture fine tuning.

As we are all in a digital age, I didn’t have anything that I could control with pots, and the two things I do have (channel and volume, both up down buttons) will be controlled with the two main knobs (coming soon). So I came up with a very simple crude method to convert the knobs to more useful push-buttons.

Here is the assembly of the original potentiometers (one black knob missing).

The original Videosphere tuning knobs

Here are the standard red push-button switches that I had lying around.

Three generic red push-button switches

And here is the idea, cut the original black knobs in half and mount the push-button switches underneath.

The concept, the knobs converted to buttons

I create a basic bracket from some folded sheet metal and mount the push-button switches.

The knobs mounted in a sheet-metal bracket

On first test the black knobs were slipping of the head of the push-buttons as there was too little surface area. To solve this I epoxyed some small sheet metal channels to the base, this stopped the knobs slipping off.

Here they are all sitting on the heads of the push-button switches.

The push-buttons with the knobs sitting on top

What is looks like inside when mounted to the Videosphere.

The whole thing mounted inside the Videosphere

And what it looks like from the exterior, looks pretty much the same as it originally did, except we have three useful buttons.

Looks exactly the same viewed from outside

Now what’s going to be connecting to the buttons, well, the LCD TV has seven buttons already, two for volume up and down, two for channel up and down, one for ‘menu’, one for ‘power’ and one for ‘TV/AV’. The three buttons will be used for the later, with the power button of the LCD TV sharing the same button as the computer.

Here is a shot of the original LCD button PCB, I keep the whole thing and mount it inside as it allows me to trouble shoot things. The IR receiver for the remote I thought of keeping, but couldn’t think of anywhere good mount it, plus having already mounted the LCD made it very difficult to drill holes anywhere close to the LCD.

The LCD TV control panel PCB

The following shows the button PCB mounted and buttons wired up, also added the VGA cable.

The original TV LCD control panel PCB mounted and wiring started

ComputerSphere – Installing the LCD electronics and testing

After a very long break, I’ve decided to complete this mod once and for all.

This update is mainly to make sure the LCD is still working after sitting around for a number of years, and confirm I still have all the parts.

Firstly, let’s make sure the LCD is still working.

A quick test of the LCD making sure it is still working

Now we need to create something to mount the various parts, which include LCD circuit board and motherboard. I thought of an easy solution, use the existing CRT mounting holes to create threaded stands that all the components can be suspended from.

I picked up some 65mm threads and matching bolts from the local hardware store, these were threaded into the original plastic bezel holes.

65mm bolts and nuts used as the main mounting supports
Screw the bolts into the existing CRT mounting holes
All bolts screwed in, but need to  remove the bolt heads

A Dremel solves the problem of the original bolt heads in the way.

A Dremel easily solves the removal of bolt heads

Mount all the LCD TV’s hardware on the first metal sheet.
Mount the LCD TVs electronics, insulating certain areas with tape

I give it a test run and notice a strange vertical white line running down the centre of the LCD, I thought some connection must be loose, but all the wiggling and playing around I was not able to resolve it.

Run another LCD test, for some reason there is a strange white line

I will just have to leave it for now and come back to it later.

Next step is working on the buttons and knobs.

hdmiOn – a solution to loss of DVI video EDID signal on HD TVs

The last few days I have been pulling my hair out over my new HD TV not working with my Home Theatre PC, specifically when switching from HDMI input to TV and back again. The HDMI signal is lost and can only be reset by either rebooting the PC or unplugging and replugging the HDMI cable.

This problem seems to affect ATI video cards only, with NVIDEA updating their drivers to fix this. ATI states that Catalyst drivers at version 7.3 or higher have fixed this problem, but that wasn’t the case for me. A Google search for ati hdmi edid shows a number of users with the same problem.

Hence, I present to you my solution; hdmiOn.
hdmiOn is a tiny program that turns the monitor off and on, which resends the EDID data bringing back the TV to life. Suggested usage is to assign the program to a function or hotkey.

Program was tested on my Sony BRAVIA KDL46X3100 with a ATI HD 2400 PRO.

Download hdmiOn.exe

As requested, source code as follows;

#include

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
	// Turn off monitor
	SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, (LPARAM) 2);
	// Turn on monitor
	SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, (LPARAM) -1);

	return 0;
}

Update July 2012
In order to stop the ongoing false positive detections, I have ported the program from C to VB6. It should function exactly the same, but let me know if there are problems.
Source code as follows;

Private Const HWND_BROADCAST = &HFFFF&
Private Const WM_SYSCOMMAND = &H112&
Private Const SC_MONITORPOWER = &HF170&
Private Const MONITOR_ON = -1&
Private Const MONITOR_OFF = 2&

Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" ( _
    ByVal hWnd As Long, _
    ByVal wMsg As Long, _
    ByVal wParam As Long, _
    ByVal lParam As Any) As Long

Private Sub Main()
    SendMessage HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, MONITOR_OFF

    SendMessage HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, MONITOR_ON
End Sub

Update August 2012
I have had a user report that the new version doesn’t function the same, I have uploaded the old version, it can be downloaded here;
hdmiOn (old version)
Zip password is “hdmiOn” (capital O)

Integrating an LCD TV with the Videosphere

As I previously posted, I purchased a 8.4″ LCD TV for around $150.

Here is the last update for the year, going on holidays and won’t be back till mid January.

I have started to try to mount the LCD TV into the Videosphere. Firstly removed the LCD from the plastic housing
Removing the LCD from the plastic housing

This is a photo of the back of the LCD
Underside of the LCD

First fit test. You would not believe how close this panel is to not fitting. When choosing the TV I only was concerned about the LCD size fitting the hole, I did not think about the housing. Being a cheap quality LCD the housing protrudes a fair bit. You can observe that the housing isn’t quite flush and this is for two reasons, the LCD is slightly too big, and the hole is actually curved due to the curved screen of the original CRT.
Fit testing the LCD to the Videosphere

The way I solved the LCD size problem was grinding the corners down. This was fairly dangerous as it was easy to damage the LCD, I still haven’t tested the LCD to see if it still works. Before grinding I disassembled the metal housing, this was so that I could see where the glass was as you do not want to be grinding that.
Removing the metal housing from the LCD

Here is a photo of the ground corners of the metal housing; I will explain what the cardboard is for next.
Metal housing with corners ground down

This now solved the LCD not fitting problem. The next problem was the gaps caused by the curved hole. This was solved by using car body filler. First I made a cardboard template with the exact same size hole as the Videosphere.
You can observe the LCD metal housing on top of the cardboard below.
Cardboard template created from the metal housing

It was secured to the Videosphere with some tape.
Cardboard template secured with tape
Front of Videosphere with cardboard in place

Car body filler was applied liberally over the cardboard.
Car body filler applied to Videosphere hole

And the sanding process began.
Initial first phase of sanding

I decided to buy myself an early Christmas present to speed things up. $125 from Bunnings, includes the Flex Shaft and 55 accessories.
Dremel 300 boxed

This was the finished results after another layer of car body filler. It took me a while to get used to the Dremel as I was taking too much out of some areas and leaving indents.
Finished result after sanding

I am quite happy with the results so far. This will be painted black making any imperfections harder to see. Below is a photo of the LCD metal housing over the hole. The hole is slightly uneven and small and that will be fixed up next year.
Back of Videosphere with metal housing used for comparison