Construction Tips

51fordf2

51fordf2

New member
Well, thought I'd start things out here - I have boards and parts in hand, so no reason not to pull the soldering iron out of the fire...

First item I have found, is that when you install the sockets for the XBee, be very careful when you solder them in. You don't need a lot of solder. It appears that the solder can wick into the hollow tubes that the pins from the XBee go into. Haven't attempted to try to solder-suck it out, yet. It's only one hole, out of 20 on the one board, but it's enough to only allow the XBee to go about 1/2 way in, and when you look down in the hole, it's silver, instead of brass/copper. Pretty sure that's what has happened.

Perhaps the mod-gods can make this thread a sticky?

Roger
 
UPDATE - that's definitely what happened. Rechecking all of them, in the light of day, it ended up happening to 5 holes, all together on 2 boards. I have a really nice bead on the back side, on the pad, which is apparently NOT necessary. If you use enough solder to make a nice bead, you probably have too much. I am heating the desoldering iron right now, to attempt to save the sockets, but I might have to replace them. I have to get them hot enough, to turn all the solder up in the "tube" molten, and not sure if I'll be able to save them that way. I'll keep all informed...

Roger
 
Sticky for now...although I'm not a big fan of sticky threads (especially if too many become sticky).
 
Update Two - I tried to suck the solder out, in place. No joy. So, I ended up taking the socket strip out. Very clear how the solder filled the "tube". At first, I removed each brass connector by pulling it out from the pin side, and tried to suck the solder. Worked great, until one of them decided to part company with the pin, before coming out. So, now I have 9 "extra" connectors, and will be buying a few new sockets. However, I am only assembling 3 boards, so I have one extra set, and it won't hold me back. Minor setback...

I did find that I can leave the brass connectors in place, and use the solder sucker on each individually, and it will remove the solder, and allow it work properly. I am posting some pics, but you can see that it narrows, where it holds the pin of the chip. On some, the solder filled behind the narrowing, but on some, it actually bridged where it narrows. Those are the tough ones, you need to get it all out of there. I tested it with a resistor cut-off lead.

The important thing is, TRY TO AVOID THIS IN THE FIRST PLACE! The holes in the board are somewhat larger than a lot of boards, on these pins, and by the time you fully fill the hole, as you normally might, it has wicked into the connector itself. I would advise just using enough solder, to be level with the pad on the board, not a nice little mound, as I normally do.

Hopes this prevents anyone from repeating my errors...


P. Short said:
Sticky for now...although I'm not a big fan of sticky threads (especially if too many become sticky).
Click to expand...

Thanks, Phil - with the first 30 or so systems being built, I think it's important to keep this one at the top.
 

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Hi Roger -

Not having the parts in hand it's a bit hard to visualize this. Can you show this from a higher level - that is what the entire socket looks like, etc. I think I understand what you're saying but it would be good to see it from the board level also.

Thanks for the tips!
Brian
 
Brian - sure. It's really not a socket, per se, but "rails". I am posting several more pics - the first and 2nd are the rail above the board, and two of them installed. These hold the XBee radios. The 3rd and 4th photos are of the back of the board. The 3rd is how I have always soldered pads, nice, clean rounded joints. That's how I did the rails, and that is too much! The 4th photo is ugly, but that's how I ended up soldering them, to keep solder out of the connectors - very minimal solder, just enough to be a good connection. Then test to make sure the XBee will go in. I'm sure it will look a little better, once I clean up the flux, etc.

Hope it helps...

R
 

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Perhaps it would be better to use a machined-pin socket, such as one of the Mill-Max sockets from page 1440 of the current Mouser catalog. They are more expensive, and sometimes break when you split them apart, but there won't be any problem with wicking up the solder.
 
Then it's a different page in the mouser catalog...looks like page 1438 for 2mm in-line sockets.
 
Thanks for the extra pix Roger.

Looks like cutting the Mill-Max parts up is about the only option for those since they don't appear to make a 10-pin version - in fact it looks like Mouser only stocks the 50-pin version.

Perhaps we can ping Digi as to what socket/header they recommend? (if this hasn't been done already...). This would be good for future buys to nail down.

*update* - I emailed Digi just for grins - let's see if I get a reply...

Brian
 
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These parts work just fine, if you are aware of the tendency to carry the solder up, if you use too much. I saved all but one. When I re- soldered them, no problems at all. Again, just have to be aware of it, and use a little less solder than you might otherwise.

On another note, I have 3 main boards assembled, and the initial test, power and power supplies, and all is good! Ready to put in the chips, and get some blinky!

R
 
Here is the response from Digi:

The receptacles used on Digi development boards are manufactured by Century Interconnect. Several other manufacturers provide comparable mounting solutions; however, Digi currently uses the following receptacles: • Through-hole single-row receptacles - Samtec P/N: MMS-110-01-L-SV (or equivalent) • Surface-mount double-row receptacles - Century Interconnect P/N: CPRMSL20-D-0-1 (or equivalent) • Surface-mount single-row receptacles - Samtec P/N: SMM-110-02-SM-S Digi also recommends printing an outline of the module on the board to indicate the orientation the module should be mounted.

I found the Samtec connector (since it is through-hole) on Digi-Key:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=SAM1230-10-ND

Not sure if this one will be better or not - might be worth it to buy a set and compare. I'm willing to get a pair just to see if they are better.

Brian
 
budude said:
Here is the response from Digi:

The receptacles used on Digi development boards are manufactured by Century Interconnect. Several other manufacturers provide comparable mounting solutions; however, Digi currently uses the following receptacles: • Through-hole single-row receptacles - Samtec P/N: MMS-110-01-L-SV (or equivalent) • Surface-mount double-row receptacles - Century Interconnect P/N: CPRMSL20-D-0-1 (or equivalent) • Surface-mount single-row receptacles - Samtec P/N: SMM-110-02-SM-S Digi also recommends printing an outline of the module on the board to indicate the orientation the module should be mounted.

I found the Samtec connector (since it is through-hole) on Digi-Key:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=SAM1230-10-ND

Not sure if this one will be better or not - might be worth it to buy a set and compare. I'm willing to get a pair just to see if they are better.

Brian
Click to expand...

Brian,

I looked at the specs for this new socket and I think it could have the same issues as the current socket. It is constructed in a very similar manner as the current sockets. Also at $4.45 a piece it is not an economical solution. For less than this price we could use the machine pin sockets from MilMax.

I've used the current socket for two different boards without any issues. You shouldn't need to flood the hole with solder. When I solder a joint I heat the pad and pin for about 1 second then apply the solder to the opposite side just until it flows across the pad. All of the holes are plated through so there is no need to flood it with solder until it wicks up into the socket.

It was mentioned that the holes were a little too big. This is true, the specs for this socket call for a hole that is 29-33 mils and the current hole is 35 mils. This is a left over from a different socket I used on the design of the Prop 128 v1. I will correct this in the next revision of the board to be a 31 mil hole.
 
As I mentioned, probably MOST (if not all!) of it is my technique, and what I've alway felt to be a great solder joint - a little bit of solder mounded on the pad. When I did the sockets, after I lifted the iron, the solder "dropped" into the hole, flush, or a little bit lower than "flush". I thought it was not enough. Since the socket is flush with the board, you can't see it, but I am VERY positive that the "mound" I would normally see on the bottom of the board, was transferred to the top (component side), as looking at the other components, the resistors, etc, I see that there is a mound on the component side of just about every one of them. So, I had my mound, just on the opposite side I am used to. Now, to add more solder, I left the iron on a bit longer than I normally would, which, of course, would melt the mound, and probably over-heat the entire brass connector inside. Then, when I added more solder, it was primed to fill the entire connector. Mea Culpa, folks.

I think with just a LITTLE care, it wouldn't happen to anyone else, especially if you know about it. I suggest you look at the resistors, after soldering, and see if the mound is on the component side, as mine are (as well as the bottom side), and adjust your soldering accordingly. Of course, if it would happen to anybody, it would be me, that's why I don't buy Lottery Tickets!!

Again, on a good note, I have a Network Controller, and two Network nodes, totally populated, and running the testfile - got Music, and the prettiest dimming and blinking lights I have ever seen. Working on getting all the communications ironed out, and Greg gave me some things to try. But believe me, it's going to be great!!

Roger
 
fair enough - just thought I would check into all the options.

Anyway - got my Mouser parts pack from Roger today so just waiting for the boards/parts from Greg so I can join the club! I've got 2 LEDtriks to build also so I got plenty of soldering "practice" to keep me busy in the meantime. :-?

Roger - are you testing both Mode 1 and 2? just curious...

Brian
 
Brian - glad the parts arrived safely.

Currently, I am just testing Mode One at this time. I'm sure I'll be testing Mode Two before it's all said and done... I have a 4 system network, that I am putting together, but will only be using 3 for the show, keeping the 4th for a "back-up". There are limitations to Mode Two. I was originally planning on running it with two FireGod systems, but after talking with Greg, I decided to go solely with the Helix, in Mode One. Who knows, I may end up doing the entire town, instead of my street...

Here's how Greg explained it:

If you plan to operate this system in Mode 1 (stand-alone operation) then I'm confident that it will run 4 systems; however, if you will be operating it in Mode 2 (wireless control via a PC) then it may not work. I haven't been able to get the XBee Pro radios to work consistently at anything higher than 57,600 bps. The amount of data that has to be transmitted in Mode 2 will allow 256 channels at a 50ms event period. If you go to a 100ms event period, on paper at least, you should be able to run 512 channels. I haven't been able to test this since I have only one Helix system.

Mode 1 doesn't use nearly as much bandwidth. In Mode 1 the main controller only has to send a 5 byte synchronization message for every event as compared to 1 byte per channel for Mode 2. I’ve been able to test that this works by having the current Helix firmware send this 5 byte message and checking to make sure it didn’t impact the timing of the sequence. The system I was running at the Ohio Mini was operating that way. I was able to verify that the messages were being sent by monitoring them with my laptop. I have no doubts that the other systems in the Helix network can use this message to keep in synch.

If you really want to run 512 channels then I would recommend only running the system in Mode 1. This would prevent you from running the FG systems on the same sequence.

Now, onto the latest news - I have the Main Network Controller board complete, and fully tested. I had a few problems, with the Controller board, not talking with the PC. Had a glitch in the Config file, but with Greg's help, we figured it out, and have now tested it, under command by the PC. Started both the Network Supervisor and the board at 1:35. Had ShowData set to start at 1:40 and to stop the program at 1:45. Worked great!! Success! Now off to build the daughter boards...

Thanks, Greg, for a super system!

R
 
Good to hear! I will probably use Mode 2 this year with the single system that I will have so that I can run my mix of Helix, 2x LOR and 2x LEDTriks. Next year I may move to a Mode 1 dual Helix (and sell off the LOR stuff) and figure out how to sync the LEDTriks to it somehow.

Brian
 
budude said:
Roger - are you testing both Mode 1 and 2? just curious...
Brian
Click to expand...

Brian, I did a test Mode 2, last night. I threw a small sequence together, at 25 ms, with very rapid flashing, 25 ms apart, then 50 ms apart. Seems to drop out a few events, when off and on very rapidly at 25 ms. I would program it at 50 ms. I always thought I would do my sequencing at 25, but after seeing it, I wouldn't anyway - too fast for me - so I'll probably be sequencing at 50 ms from now on. I just tested the Network Controller board, but the Mode 2 can be used to test the Network Node boards, as well - just need to load the config file in. Right now the firmware doesn't allow the Nodes to talk to the Controller board, but Greg will be working on that, when he gets his 2nd system up and running.

I'm still having a difficult time with the order of plugging things in and turning them on. It is important, and it takes me a while to get it right. It's because I don't fully understand the boot-up, and the config, but I'm sure I'll get it down pat. Lot's more reading to do.

On a side note, Greg mentioned that when you set up your sequence, the timing MUST be in multiples of 5 - 25, 30, 35, etc. The programming looks for it. I can't think of any reason for a person NOT to use multiples of 5, like 48, 52, etc, but it won't work. Just something to keep in mind...

Roger
 
Well I'm officially a member of the Helix club! Instead of doing my lawn work like I should have, I decided to put my controller and daughter boards together. The only vaguely difficult part was cutting the SIP socket down into 10 pin pieces for the MP3 module. I initially tried heavily scoring the indents and snapping it but it broke partly into the socket portion (the half I needed of course!). I found the best way was to cleave it in two by using a blade for a utility knife (just the blade insert itself) on the joint and tapping lightly. This cut it off very cleanly. I did the same for the header pins.

The only other thing was that I inserted the sockets for IC6 and IC7 upside down and ended up putting in the chips the same (wrong) way. After getting to about 5 million degrees, they must have popped internally before I realized what I had done. I replaced them (in the right direction this time) with two from my daughter boards. This was rather a silly mistake and one that could have been avoided as it is spelled out on the silk screen and page 17 of the assembly manual... oops...

After power-up the heartbeat came on OK and I plugged in a test SSR rig. Greg indicated the controller does a light test on it's own and sure enough I confirmed that all 32 channels are working OK (at least simple on/off anyway) on the main board.

Next I'll try the SD testfile test sequence and see how it goes. woohoo!
 
The easy way to cut SIP’s is to cut right down the middle of the next pin up. You’ll sacrifice a pin, but it’s the thinnest part and it cuts easily.

This works for headers and sockets. If you can pull the pin out first, you won’t need to cut through the pin too.
 
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