---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 04/19/12: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:14 AM - Re: Open source product development for OBAM aircraft (Eric M. Jones) 2. 07:29 AM - Re: OS Wig-Wag Project (gregmchugh) 3. 07:46 AM - Re: OS Wig-Wag Project (Robert L. Nuckolls, III) 4. 08:31 AM - Re: OS Wig-Wag Project (Daniel Hooper) 5. 09:11 AM - Re: OS Wig-Wag Project (Robert L. Nuckolls, III) 6. 09:14 AM - Re: Re: OS Wig-Wag Project (Robert L. Nuckolls, III) 7. 08:16 PM - Antenna mounting-doubler (Rick Lark) 8. 09:13 PM - Secrets Techniques (John Loram) 9. 09:28 PM - Re: Antenna mounting-doubler (Robert L. Nuckolls, III) 10. 09:37 PM - Re: Secrets Techniques (Mike Nellis) 11. 11:19 PM - Re: Secrets Techniques (John Loram) ________________________________ Message 1 _____________________________________ Time: 06:14:44 AM PST US Subject: AeroElectric-List: Re: Open source product development for OBAM aircraft From: "Eric M. Jones" > Eric: Express PCB is also very good. The only disadvantage is that it is linked to the particular board supplier - which is fine as long as that is who you want to deal with. With Eagle you can use > the Gerber files it generates with any board supplier. Dick, ExpressPCB is full of surprises. They will send you the Gerber Files for a small fee after the first run, I believe. (Check with them for the most recent policy). Their mini-board service also expands to almost anything else you want, other sizes, two or four layers, other quantities, for competitive prices. They also don't quibble about the number of boards you put on one sheet, although they have a limit of 350 holes per sheet on their standard 3-PCB mini-board service (...and I bump up against the hole-limit all the time!). ps: Don't confuse the original "Express PCB" with the copycat "PCB Express". -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=371262#371262 ________________________________ Message 2 _____________________________________ Time: 07:29:44 AM PST US Subject: AeroElectric-List: Re: OS Wig-Wag Project From: "gregmchugh" Bob, Looks good for what I would need for a wig-wag... Here are some possible typos I think I picked up... On page 2 the processor part number is listed wrong. On page 3 at the top right I think that it should read P-1, not P-11. On page 3 Pin 6 of the micro is being used as GP1 in this application. On page 3 Pin 7 of the micro is being used as GP0 in this application. and a couple of questions... 1. Pin 12 on the d-sub connector seems to be unused but also shown differently than the other pins on the page 1 drawings. Is this a convention of some sort? 2. Looking at the PIC12F683 data sheet there are some confusing instructions on using MCLR with Power on Reset but I think that Pin 4 could be left unconnected for this application or used for another purpose since there is no external reset circuit. What is your reading on this? 3. Not sure how much real estate is left on the board but with Pin 4 freed up and Pin 3 unused you might be able to add the Under Voltage module functions into this module. Connect one pin as an A/D to read the bus voltage and use the other pin to drive the warning LED using a spare d-sub pin. Maybe also figure out how to handle the relay control for the aux battery. Maybe this is something for the next spin of the board... As it is, it meets my needs for a wig-wag module but I can see a software option that might be useful for users with other configurations of lights. In my case I have two landing lights on the wing and really only need to have them both off, both on, or the wig-wag. If other users have a Taxi light and a Landing light they may want to be able to have an alternate control function that allows: All Off, Taxi On, All On, & Wig-Wag (or some variation of four different states). Changing the function of the switch as shown to handle Off, Taxi, All On and then adding a second switch to ground both inputs for Wig-Wag would allow this to be done with only a software change needed to implement in the module. An option for those who would want it... It may be little early to be looking at Version 2 of the module but I will throw out a couple of items that might be useful to consider that require more than a minor spin on the board. 1. Allow for drop in of a PICAxe 8 pin module. This would require realigning Pin 2 and Pin 7 to handle the Serial In and Out for the PICAxe configuration and moving the current functions to other pins. Two resistors are the only added components for the PICAxe serial I/O circuit. Pin 7 can be reconfigured as a regular I/O pin in the application or left to handle Serial Out (maybe to a remote display?). With Pin 2 and Pin 7 brought out to the d-sub you would have the capability to connect to the PICAxe tools and do serial communication with the chip in the application via the d-sub. 2. In-Circuit Programming of the PIC is something that might be useful when using the standard PIC chip. Not sure about the need for it... 3. As I noted above, an easy add-on for the current module would appear to be the functions handled by the Under Voltage module (warning light and aux battery control). I expect that others have already come up with more ideas for using the module. With digital I/O, analog inputs, and a serial interface there a lots of possible functions for the module even with only an 8 pin micro. Lots of options, which is good... I will be continuing work on a software version to handle the basic wig-wag function in the next few days. Should have an initial version available within a week or so. Greg McHugh Read this topic online here: http://forums.matronics.com/viewtopic.php?p=371274#371274 ________________________________ Message 3 _____________________________________ Time: 07:46:41 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: OS Wig-Wag Project >I'll take another pass at the 'sieve' tomorrow >and maybe get some boards on order. I have all >the parts. Some background on the decisions that went into satisfaction of design goals: I started with the following ideas for crafting the configuration I published: 1. Use the already developed package based on Polycase enclosure and D15 connector. I have cases and lids already cut to accept the connector. Of course, this sets the boundaries on the ECB. 2. Use simple on-off-on toggle switch to achieve OFF-WW-ON control functionality. Easily handled with software logic. 3. Minimum parts count. 4. Minimum variety of parts. 5. Maximize heat-sink copper for the FETs 6. Add some functional indictors for as-development tools (a couple of LEDs) so that bench testing of software needs only a switch and power supply. ---------------- Parts selection was pretty easy. As one can see from the schematic, all resistors and capacitors are the same value. This makes it easier to order, stock, and install with minimized error. The only parts that required any "calculation for performance" was the voltage divider for the power supply (exact value not critical and they only needed to be equal). And the series resistor for the shunt regulator. The calculated optimum value could be achieved by paralleling 4 of the common bill of materials value. 4.99K / 4 gives us about 1200 ohms at better than 1 watt because the heat doesn't come out of a single device . . . but is spread over larger area. The other values go to transient immunity. Two standard practice bypass capacitors on supply rails, two capacitors and two transorbs protecting fragile silicon from stuff conducted in on the ship's wiring. This is a good example of what my cohorts at HBC called a "cotton ball" . . . very non-critical components (tells us that drifts in performance due to component tolerance/drift are insignificant). The thought processes that go toward component selection are pretty ho-hum. Not to take away from the ultimate functionality of the assembly. Once the silicon is safely wrapped in environmental cotton, the magic poured into the source code is relatively unrestricted. A similar philosophy was adopted for the 'do-lots' board from which this project evolved. Figure out a way to wrap an 8-pin PIC up in a deep sea diving suit and then teach it how to sing, dance and do dishes. I'll order boards today. As Eric mentioned, ExpressPCB doesn't fuss about what is on a miniboard (3 pieces returned in 3 days for $70). Each mini-board will give us two finished boards with a couple of avionics ground bus boards thrown in on the side . . . sorta like this: Emacs! So we'll end up with 6 boards for the development work at a cost of just over $11 each and turned around in 3 days. If I sell some avionics grounds with the 'residuals' then the out-of-pocket development costs go down. Folks interested in doing software for this project need to chime up. I'll provide an assembled board with a control switch attached. You'll need a 12v source (2 el-cheapo WalMart lantern batteries?) and a development system of your choice. I'll throw in a couple of PIC chips and install a socket on the board for ease of swapping the chip between programmer and the end product demonstration. It's my vision for this project to publish all the drawings, ECB source files, and software sources which anyone can use to carry this project (or perhaps another functionality on the same hardware) forward. Of course, most individuals accessing this data have no interest in evolving/building their own. But this could lay the ground work for others to cultivate their own ideas for other products in a garden we've already planted with expertise contributed from a family of participants. That's what Open Source is all about . . . Bob . . . ________________________________ Message 4 _____________________________________ Time: 08:31:10 AM PST US Subject: Re: AeroElectric-List: OS Wig-Wag Project From: Daniel Hooper In that case, maybe consider dropping a Open Source Hardware logo in the cop per... http://freedomdefined.org/OSHW http://oshwlogo.com/ > > It's my vision for this project to publish all > the drawings, ECB source files, and software > sources which anyone can use to carry this > project (or perhaps another functionality on > the same hardware) forward. Of course, most > individuals accessing this data have no interest > in evolving/building their own. But this could > lay the ground work for others to cultivate > their own ideas for other products in a garden > we've already planted with expertise contributed > from a family of participants. > > That's what Open Source is all about . . . > > Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:11:21 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: OS Wig-Wag Project At 10:25 AM 4/19/2012, you wrote: >In that case, maybe consider dropping a Open Source Hardware logo in >the copper... > >http://freedomdefined.org/OSHW > >http://oshwlogo.com/ Interesting! Hadn't seen that before. I'm not ExpressPCB has a feature that would allow us to craft that exact symbology onto the board . . . but certainly documents that accompany the package could included it. I'll see what I can do. Bob . . . ________________________________ Message 6 _____________________________________ Time: 09:14:11 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: OS Wig-Wag Project At 09:28 AM 4/19/2012, you wrote: Good input. Give me a day or so to get the disagreements sifted and consider the broader options. Bob . . . ________________________________ Message 7 _____________________________________ Time: 08:16:01 PM PST US Subject: AeroElectric-List: Antenna mounting-doubler From: Rick Lark Hi Bob, I'm aware that a doubler plate/skin connection for mounting a nav or com antenna requires a nice shiny surface. But, will alodining the surfaces make any difference with antenna performance? Thx, Rick Vans #40956 Southampton, Ont ________________________________ Message 8 _____________________________________ Time: 09:13:30 PM PST US From: "John Loram" Subject: AeroElectric-List: Secrets Techniques Sixty years I've been doing this! Built all my own ham radio gear as a teenager in the 50's, got a EE degree from a prestigious university, spent my adult life as a development engineer designing medical and laboratory instruments. You'd think I could strip a multiconductor shield Tefzel insulated cable in my sleep, but it's a bit@h! I make a mess of the shield when I try to remove the Tefzel. What is the secret trick to it! thanks all, -john- ________________________________ Message 9 _____________________________________ Time: 09:28:59 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Antenna mounting-doubler At 10:13 PM 4/19/2012, you wrote: >Hi Bob, > >I'm aware that a doubler plate/skin connection for mounting a nav or >com antenna requires a nice shiny surface. But, will alodining the >surfaces make any difference with antenna performance? I presume you're talking about a commercial comm wisker that mounts with 3 or 4 screws and has a BNC connector centrally located in the hole pattern. See: http://tinyurl.com/6rwodso Practical electrical connection is made with the airframe only at the areas where there are large clamp up forces around the screws. These forces go to essentially zero at more than 1/4" away from the mounting hardware. The goal is to things clean if not bright around each of the mounting screws on all mating surfaces. The end product will be the best we know how to do . . . short of welding the antenna base to the skin. The goal is 'gas tightness' within the cleaned areas . . . so screw the nuts down good and tight. Metal lock-nuts would be good. Bob . . . ________________________________ Message 10 ____________________________________ Time: 09:37:06 PM PST US From: Mike Nellis Subject: Re: AeroElectric-List: Secrets Techniques You've been doing it so long, you've probably wore the tool out or at the very least, dulled it. Mike > Sixty years I've been doing this! Built all my own ham radio gear as a > teenager in the 50's, got a EE degree from a prestigious university, > spent my adult life as a development engineer designing medical and > laboratory instruments. You'd think I could strip a multiconductor > shield Tefzel insulated cable in my sleep, but it's a bit@h > ! I make a mess of the shield when I try to remove the > Tefzel. What is the secret trick to it! > thanks all, -john- > * > > > * ________________________________ Message 11 ____________________________________ Time: 11:19:19 PM PST US From: "John Loram" Subject: RE: AeroElectric-List: Secrets Techniques Tool! A special tool!? I love tools! What tool! -john- _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Mike Nellis Sent: Thursday, April 19, 2012 9:36 PM Subject: Re: AeroElectric-List: Secrets Techniques You've been doing it so long, you've probably wore the tool out or at the very least, dulled it. Mike Sixty years I've been doing this! Built all my own ham radio gear as a teenager in the 50's, got a EE degree from a prestigious university, spent my adult life as a development engineer designing medical and laboratory instruments. You'd think I could strip a multiconductor shield Tefzel insulated cable in my sleep, but it's a bit@h! I make a mess of the shield when I try to remove the Tefzel. What is the secret trick to it! thanks all, -john- ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.