767-300 Cockpit

If you never have heard of OpenCockpits (OC from now on) before - then it's about time you take a closer look at this fantastic Spanish project. Take a deep dive at OC site and read all!! I feel that their popularity and awareness have been like a rocket the last years. One thing is their very cheap and "OPEN" hardware but not at least the use of SIOC. More and more builders "move" their cockpit logic from hardware to software and SIOC is a great scripting programming language covering that purpose very well. Check also these two sites - Nico Kaan and This.

From the day I started to plan the cockpit project, PCB, interfacing, cabling etc were very important for me to get correct. It had to be easy accessible wiring and if necessary disconnecting panels etc. At the same time it should be a very clean and nice cockpit. No spaghetti - and so it will be for sure :-)

The OC-hardware is great for just that - using their ribbon connectors. So it's just to follow up and plan your own hardware for that target. And if you need some conversion it's quite easy to fix - at least for those able to make quick PCB's. (Long live the CNC). Check the Tech section about making PCB's.

In this section I will cover my own manufacturing of OC-boards and you can ask if that's smart as long as the cost of the boards from Spain is so low. Well, first of all I get the correct PCB when needed. In other word - freedom. I can do modification as long as I comply to the interface standard - show you later. And of course the cost is lower doing it yourself - not too much but anyway lower and I don't have e.g. shipping cost. The last arguments are: FUN and the good feeling of mastering the technique!!

I did buy one MasterCard and one USB Expansion board from OC - just to get started.

MASTERCARD

The Mastercard bought from OC is used in the Glare section. Now working on the MIP I needed another one. Using the available schematic from OC and "transforming" that to my PCB program, I was ready to make my own MasterCard. Made a few modifications and changed the specific layout somewhat. The size is about the same.

Click will get you a better schematic in pdf-format.

That's about it - please ask if questions.

DISPLAY-II

I have made three samples of this board - all used in the Glaresection for the MCP and VOR's. It's a quite "compressed" board and the CNC really showed some precision. Did a few modification compared to the original - just to make it more simple to use ribbon cables out to the 7-segments displays. Also the interconnection between the MasterCard and this board is simplified - just wired those connections needed.

SERVO

The servo board from OC is a nice little piece of hardware. Controlling up to 6 ordinary RC-servos through a USB interface controllable from SIOC. Covering many functions in a cockpit - like gauges and Throttle even moving a pot-meter if you like. You also have four Analog Input. These can give you position information / feedback from your own moveable devices back to SIOC and which then can take action - either move a servo / motor / or other purposes. My version of the Servo-board is more or less the same as OC - though I did remove some "not used" connectors. I had to redraw anyway to get the "input" for PCB-layout program.

The Servo board is very simple hardware wise, but the PIC circuit with the internal micro-code make this little board a master piece!!

Click on the schematic to get a better view if you need.

USBDCmotors / USBStepper interface

These two boards are more or less identical - the USBStepper have one resistor added to each of the analog midpoint making a pull up to +5V for the output stage of the OptoCoupler - ref. the manual. DC motor version (manual) do not use these resistors. In this case better use these input for position feedback pot-meters in case of a Servo-solution or maybe a pot-meter for light-control in case of e.g. brightness control. The last major difference between DCmotor and Stepper is the microcode which you'll find at OC website together with other downloads / information.

These two board together with the Servo-board give you a lot to play with concerning "movement"
.

I have to admit having made some extra modification to this board. As you see it's much bigger than the original from OC. The reason is quite simple - replaced L293E with the bigger and more powerful L298D. The logic is the same - just more power. My aim is to be capable to drive bigger motors if needed and backlight and misc. light source in the cockpit.

Replacing the L293 with L298 is like going from 4W to 25W pr. chip. Also grounded the Sense signal to give even more power (I don't understand why the Sense signal is not grounded on the OC standard card - I know it's kind of a current limiter output - in that case put in a 0,5ohm resistor down GND.

I will be using this card (DC Motor version) as controller for all lighting in the Cockpit and I think three unit will be sufficient (3 x 3 x 25W = 225W). That should be 18 different and separately controlled power sources to run misc. LED lights - all of course managed from SIOC. Each chip have four outputs, but only two possible to use for light control - the other two is inverted (meant to run motors bidirectional). I believe it will be approx. 64 level of light intensity.
Time will show where I ends up!!! Not tested anything yet.
More on the topic later.

I also have a layout ready for the same board with L293E H-bridge drivers when needed:

Click on the schematic to get a better view if you need.

Encoder-II

If you need to attach encoders other than the standard 1/4 cycle - this is what you need. With OC's standard micro code you'll able to "talk" to 1/1cycle encoder. With a special micro code from a clever guy - Terry Adams, you are able to attach 1/2 cycle encoders. This last code is great!! and for my project essential because I have a lot of 1/2 cycle PC mice encoder I'm going to use. These are very small (shown in the picture) and are easily placed inside the bezel/MIP without touching the monitor behind. You will find a lot more information and the micro code at Terry's Homepage Thanks again for your effort, Terry!!!

Click on the schematic to get a better view if you need.

October 16, 2010 1:05