Latest project: Workshop PC, raspberry Pi and Arduino DUE combo.

cowasaki

cowasaki

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Darren
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Here goes.

The plan:

Build a replacement computer for the workshop which will deal with everyday tasks such as email, internet, forums, any Windows only software etc but also allow me to interface with my digital storage oscilloscope, logic analyser, multimeter, (upcoming 3D printer and possibly CNC lathe, miller etc as later projects) plus run the arduino IDE, flash, eeprom programming, programming, Photo Triggers project etc etc.

What I would like/the build:

New PC case with 7" touch screen TFT in front of case, DUE running all the time and connected to network and the touch screen TFT and able to switch the PC on and off at will. Take inputs from the computer and control fans etc in order to make the computer virtually silent. Raspberry Pi inside too with all devices inside able to communicate with each other. Plus more as I go along.

The idea as it stands:

Purchase a new case: Coolermaster HAF XB http://www.coolermaster.co.uk/product.php?product_id=6866

haf_xb_1.jpg



This case is a double decker configuration with the power supply in the bottom with the drives in front of it. There would be a large void at the side of the power supply but cooler master have stuck a 5x2.5" drive bay in there. My plan is the remove this drive bay and fit the Arduino DUE and Raspberry Pi plus my electronics into this space. The DUE will connect to the desktop motherboard above via one of the motherboards internal USB headers which will go to the two micro USB connectors. The Pi will attach via the network. The DUE & Pi will take their power from the PC power supply's permanent 5v connection but the Pi's will be switched by the DUE. Effectively the DUE will be master of all. The large front grill will be removed and replaced by a piece of 3mm aluminium or black plastic containing a 7" TFT touch screen. The screen will be used as the input for the DUE which will allow it to switch on the computer/pi, switch which device goes to the monitor, and more besides.

I will re-use an old ATX motherboard I have lying around at the moment but will get a new motherboard, cpu and ram later (I might be asking for suggestions as I've been out of the game for a while). I have a 120Gb SSD ready as the main drive.


So far:

I have worked out the concept and last night designed the power board which I am hoping to have time to build today. The power board and ATX motherboard will be connected to the ATX power supply with a "Y" connector. This board will allow the DUE to switch the PC power supply on and off at will by simply pulling one pin high. The DUE will be protected by a 4 port opto-couple as it only requires one directional comms on each port.

DUE_ATX_power.png
 
Well I had time to print the front and back on the film, expose it in the UV, develop it and etch...... * Still need to scour it both sides, tin it, drill it and solder it up yet.

It's just badly scanned and cropped rather than cut at an angle :D *There is about a cm all round that.

powerboard_1.jpg


and the TFT is here too.....

TFT_1.jpg
 
Well, I'm not sure why other than because (actually, a lot of mine are like that too ;)), but let's see what comes of it....
 
arad85 said:
Well, I'm not sure why other than because (actually, a lot of mine are like that too ;)), but let's see what comes of it....
Click to expand...

The Arduino DUE can emulate a mouse and keyboard so I can have the display on the computer case showing a number of "buttons" then by pressing any one of the buttons the DUE can switch the computer on, login and run the relevant program etc etc. I will also be able to use the DUE to control everything in the workshop. It's about time I built a new Windows computer, my old one is running an 800 series Pentium 4 :D
 
Would you not be better off with an Arduino 2560 board which is supposed to be more powerful.

I'm waiting for my Pi to arrive, I'm looking at some home brew projects mainly to do with panoramic photography.

No idea why someone suggested an iPad, I'd love to use it to control things but unfortunately they are just a dumb terminal.

Very interested in the TFT any chance of some details ?
 
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Have you considered how you are going to keep that thing cool? The case does look to have good cooling air flow, but you are going to be blocking up the front grill which, when stock, is the air intake with 2 fans there. The case has a front to back air flow when stock. Blocking up the grill and removing the fans is going to severely restrict air flow.
 
ChrisH said:
Would you not be better off with an Arduino 2560 board which is supposed to be more powerful.

I'm waiting for my Pi to arrive, I'm looking at some home brew projects mainly to do with panoramic photography.

No idea why someone suggested an iPad, I'd love to use it to control things but unfortunately they are just a dumb terminal.

Very interested in the TFT any chance of some details ?
Click to expand...

No the DUE is far more powerful than to 256O. The DUE is running an ARM processor at 82MHZ rather than the 16MHz of the 256O. It also has more RAM etc. The only real issue For most purposes is that not all the libraries are DUE compatible. the machine will be doing a lot more than I have already said eg wave generator etc-
 
joesmith said:
Have you considered how you are going to keep that thing cool? The case does look to have good cooling air flow, but you are going to be blocking up the front grill which, when stock, is the air intake with 2 fans there. The case has a front to back air flow when stock. Blocking up the grill and removing the fans is going to severely restrict air flow.
Click to expand...

Im not goIng for a scorching fast machine and there is the sides and top to for ventilation
 
Cheers for the heads up on the Due / 2560 boards.

I've unfortunately ordered a 2560 board but for my needs of driving a couple of servo's and minimum need for feedback loops it should be ok.

I will be following your project with interest as I have an old Soltek cube similar to what your looking at hiding in the loft.
 
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ChrisH said:
Cheers for the heads up on the Due / 2560 boards.

I've unfortunately ordered a 2560 board but for my needs of driving a couple of servo's and minimum need for feedback loops it should be ok.

I will be following your project with interest as I have an old Soltek cube similar to what your looking at hiding in the loft.
Click to expand...

I do a lot with the programmable microprocessors now and there is quite a range. The lowest normal ones are based on the 328p which give 32K and, I think, about 20 i/o ports which have a mixture of PWM, Anologue, normal, with and without interupts etc. These cost about £2-3 and only require a clock, a resistor and three caps to run or a board costing about £12. Then you jump to the 1280/2560 boards these have 128K or 256K and 84 i/o ports. All the boards mentioned so far have 5V i/o which is VERY useful. There are a few specialist ICs amongst the lineup such as smaller than the 328p or one I really like called the 1284 which is a DIL IC with 128K and about 8 more i/o ports than the 328p.

The newer two arduino compatible ICs are the DUE and LEONARDO both of which run at 3.3/3.5v this causes issues with some external logic or if you use them with external boards! The LEONARDO is special as it's USB port can be used to emulate a USB device so you can make something that looks like a USB midi card or keyboard or mouse. The DUE like the LEONARDO uses the same lower voltage but has more i/o than the 2560 and runs about 5-6x quicker plus it has 2 USB ports which allows it to use one like the LEONARDO whilst still connected to your computer with the other for programming etc.
 
I'm looking at doing this as part of an open source hardware/software project......

The first board is designed as can be seen above and I've just re-done it smaller:

powerboard_2.png


If you look closely at the top right you will see a 10 way connector. This connector carries all the signals back and forth between this, the power i/o board, and the processor board. These two boards can be connected by a ribbon cable OR if printed on the same circuit board will avoid the need for the ribbon (hence the tracks continuing to the edge).

The next board will be the processor board and I am doing 2 versions. 1 version will have the processor soldered to the actual board whilst the other will have the contacts to basically plug into a DUE board so.

Then we can look at options such as.....

  • Fan speed control.
  • TFT touch panel connection.
  • Water pump control (ie starting pump, check pressure, start computer, stop computer then after temp down stop pump)
  • Web interface (allowing re-booting, resetting CMOS, typing inc pre-os etc)
  • Monitoring temperature (maybe 4-5 sensors), fans (maybe 4-5), etc etc by web interface AND TFT screen
  • Control relays to turn on lighting, fans etc etc
  • IR receiver and IR transmitter to receive signals from IR remotes, IR keyboards etc and then do something once a signal is received such as relaying a keystoke or turning a relay on or off.
  • Input from buttons on the case (inc additional buttons) plus rotary controls etc.
  • Input from a serial port on the computer (most ATX boards have a spare COM header inside). So this can go to the processor board and allow anything to be controlled via serial commands from your own programs on placed into BAT or script files.

and lots more as people can think of things......

The basic program can be written and heavily remarked so that anyone can see what does what THEN additional elements can be written and inserts as and when necessary.

If you look at the circuit board above, all the connections are on the bottom with nice fat tracks so it should be easy for people to make their own circuit boards BUT if a few people fancy having a play boards can be made for about £5-£10 depending on quantity.
 
Well version 1 board is complete other than a capacitor and voltage reg, both of which I have run out of.


powerboard_3.jpg



Will get them tomorrow and it should be sorted.
 
Well Scan messed up my order today due to a fault on their computer system which showed it as not authorised when it was! So no case today but hopefully tomorrow. I have got the missing components for the power board though so hopefully tomorrow I can collect the case and finish and test the power board. Then order a new 7" screen and a second Due so that I can leave them in it. Also ordered 8 micro USB leads for £4.95 inc delivery so that I can chop 3 of them and attach them to headers to connect the DUE and Pi internally......

Having produced a "to scale" LCD box to place on the case it would appear that I can possibly get TWO 7" displays in the front...... This would allow one for the DUE and a second one which could be switched between the Pi and PC....

front-design.jpg
 
Looking good so far. I know the feeling about waiting RS showed they had Pi's in but they hadn't. Got to wait until 9th for delivery.

Got my Arduino mega board yesterday not had time to play yet.
 
ChrisH said:
Looking good so far. I know the feeling about waiting RS showed they had Pi's in but they hadn't. Got to wait until 9th for delivery.

Got my Arduino mega board yesterday not had time to play yet.
Click to expand...

CPC always have lots of Pis in stock and it's free delivery.
 
Problem is they add a handling charge that makes them £5 more than RS.

Going to cancel the RS order tommorow and order one from CPC instead as I want some other bits and bobs.
 
ChrisH said:
Problem is they add a handling charge that makes them £5 more than RS.

Going to cancel the RS order tommorow and order one from CPC instead as I want some other bits and bobs.
Click to expand...

The handling charge is an error on their system, I was speaking to them today as they are only 5 miles from my house. They take it off manually. It is free oisrage on all Internet orders no matter how small.
 
cowasaki said:
It is free oisrage on all Internet orders no matter how small.
Click to expand...
I've never had oisrage... free or not. Am I missing out :shrug:
 
Great stuff, my ishould arrive tomorrow and I.ve ordered a breadboard and some other bits.

Programming looks fun, back to my BBC micro days.

I ended up with an Arduino 2560 board but it will meet my needs for now.
 
Well I've got the case. There is plenty of space inside the case for the pi and due. One of the front fans fits nicely in the space at the back and the grill has detached nicely. Should be space in there for two 7" LCDs and a bit more besides.... I need to find a flat piece of plastic 370mmx160mm and maybe 1.5mm thick for the front panel next.
 
Now that I've got the case open it would appear that there is a nice space between the 3.5" drive bays and the right hand side of the case. Also due to the layout of the case a modular PSU wouldn't actually give me any real benefit so with that in mind I've redesigned the power board again so that it fits and with TWO ATX sockets. One will connect to the PSU the other will allow me to connect from the power board to the motherboard using a modular ATX power cable which are about £8 and so cheaper than the Y cable too.


powerboard_4.png
 
You got enough current carrying capacity in those tracks to handle the ATX->ATX Darren?
 
arad85 said:
You got enough current carrying capacity in those tracks to handle the ATX->ATX Darren?
Click to expand...

They are 32 thousandths of an inch wide. I had considered that whilst I was tidying the design up. There is scope for making them thicker but I need to find a table of power allowed against certain track widths. 40th is easily possible so that's an easy change. Would be so much tidier with this board and I've added two dip switches - one gives 5v to the controller board allowing a 2560 or 1280 to be used instead of a DUE whilst the other turns on two LEDs at the bottom which show ATX power ON and ATX power OK plus there is a manual power button too.

EDIT: I've asked Mike MMCPIX to take a look as I have relatively little experience with PSU and analogue design mainly working with logic circuits etc.....
 
Rushing out now but I have changed the 12V EXT power and some GND to 66 thou wide. It wouldn't be possible to change them all because I couldn't get the tracks from pin to pin at that thickness...

powerboard_4b.png
 
you should try running the ulp called length-freq-ri.up (in the ULP library)
shows you max frequency (not relevant here) and maximum current capacity for every track :)

PS your second board has a bad case of the acid traps aagain
tsk tsk I have taught you nothing grasshopper
 
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mmcp42 said:
PS your second board has a bad case of the acid traps aagain
tsk tsk I have taught you nothing grasshopper
Click to expand...


I know ; ) I try to stick to the PCB rules you told me about but as a prototype being hand built certain other constraints kick in first such as blue connections to pins, no top connectiobs if i can, thicker tracks and track to pin gaps etc

They are certainly much better now than they were (y)

Etch on..... etch off.... etch on..... etch off :)
 
Just ran the details through that calculator as I'm out at the moment and it suggests 20 amps for a 32 thou track! I'll check with eagle tomorrow.
 
Well I've stuck my iPhone5 up in the classifieds so when it sells I have decided on the following for the PC side of things:

  • Gigabyte GA-H77M-D3H, Intel H77, S 1155, DDR3, SATA 6Gb/s, SATA RAID, PCIe 3.0, D-Sub/ DVI-D/ HDMI, Micro ATX @ £76.52inc VAT
  • 16GB (2x8GB) Corsair DDR3 XMS3, PC3-12800 (1600MHz), Non-ECC Unbuffered, CAS 11-11-11-30, 1.5V @ £89.18inc VAT
  • Intel Core i7 3770,1155, Ivy Bridge, Quad Core, 3.4GHz, 5 GT/s DMI, 650MHz GPU, 8MB Smart Cache, 34x Ratio, 77W, Retail @ £239.00inc VAT
Should be a good upgrade from the Pentium 4 2.66GHz (overclocked to 3.33GHz) with 4Gb DDR2

I'll use the onboard graphics to start with, I want it as quiet as possible.
 
Well with a lot of messing I now have FAT tracks for the ATX ATX bridge.....

powerboard_4opt.png



The only way I could get the fat tracks into place was to merge all the 12v lines, all the 5v lines, all the GND etc etc...... Having looked virtually all PSUs now have one rail anyway.
 
I've been following this keenly, any news on the build?
 
Rico said:
I've been following this keenly, any news on the build?
Click to expand...

Well the first 7" screen arrived and had the 32pin connection so I got a refund, the second 7" screen had the correct 40pin connection but was a 5v unit rather than a 3V5 one. Yes I could use either of these but with a lot of messing around as the circuit is designed for a 40pin 3v5 one.... So waiting on the main screen. The second screen is a HDMI screen for output from the PC or Pi so no issues there...

The Computer itself is built inside a spare case and installed with it's first two operating systems Windows7 and another one which we can't mention ;)

The power control board is designed and the prototype is tested and working....

The finished unit will be able to control 2 separate ATX power supplies as it had a spare opto-couple and with a little messing that was an easy add.

The board with connects to the display, controls 6 fans, controls upto 8 relays, reads 6 temps, controls the switching of computers on and off, etc etc etc and basically does all the clever stuff is still in design at the moment..

I'm still looking for a supplier of pieces of black plastic around 2mm thick for the front panel insert and part of the rear panel....

There will be another update shortly but it is a matter of waiting for stuff to arrive from China at the moment......
 
Darren, re 2mm black plastic. Model shops usually stock A4 sheets of white plasticard in various thicknesses and suitable paints.
 
Nod said:
Darren, re 2mm black plastic. Model shops usually stock A4 sheets of white plasticard in various thicknesses and suitable paints.
Click to expand...

I could do with the plastic in black really but that is certainly a good idea. Two replacement TFT screens on route as I want one for another project. The computer itself is built. Hopefully tomorrow I will get chance to build all the PCBs that I have outstanding. The ATX power sockets arrived this morning from China so I now have all the components for the power board.
 
Well the case is here and really very nice. I've installed two of the OSes onto their own SSDs and it is fast at 3x the speed of my MacPro (using geekbench 32bit under MacOS).

The ATX PSU control board is built and fully tested and working.....


Powerboard5_image.jpg


Powerboard5_PCB.jpg



I didn't have any PCB option switches so there is a wire link to the bottom left which would be an on/off switch. There are 2 which select the connected computer's voltage between 3.5v and 5v. This board will work with either a DUE or a 2560. I've left out the 0.1uF electrolytic cap as I didn't think I would need it because the ATX PSU is regulated anyway. The only other thing is that the push button that is fitted as a test button is a push to make rather than a latching button so the ATX PSU only stays on whilst you push the button.....

Next job will be the main control board which will be next..... I might have to upgrade Eagle to the next size upwards board though...
 
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