RaspberryPi + LinkMeter blue sky discussion


 
Jeff, looks like John's got the last board claimed. I've got another set already on order though, but it hasn't been sent to fab yet. It should be about 2 weeks until they show up at my place. You can either order yourself 3 boards, or wait until mine come in then I can ship you as many as you need (up to 3). I'm considering doing a larger run in the future though so there will always be some on hand, if there's enough interest.
 
Bryan,

I compiled the hex file from CapnBry-HeaterMeter-cb1762d... all seems well now with SRTP and Min fan speed.

Too late tonight to rig up the heater, but if I set 100% as min fan speed, I can control with a precision of 10%

Well done!! This should make for really nice control over heating elements.
 
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Huzzah! Yeah I was looking at the code last night when I saw it wasn't working as expected and thought "What the hell? Didn't I fix and test that?" then checked github and realized I hadn't pulled the latest version before building.

I killed another rPi! Man, those things really don't like having 12V just randomly attached to them. Plugging it in, the input fuse gets scorching hot immediately and it looks like the 3V3 regulator is shorted to ground. I've ordered a handful of TO-252 LDOs to see if I can swap it out to bring it back to life.
 
Bryan,

I sent you some PayPal cash for two boards when you get them. I'll start working on gathering the parts. I plan on getting both working then seeing if I can pot one in acryllic.

Thanks for all your efforts.

Jeff
 
Jeff, given than my panel hasn't even been sent to fab yet, you can get in on that order and get 3 boards shipped directly to you rather than going through me if you want. The panel goes to fab tomorrow 9/13 so let me know if you'd rather do that and I'll refund your paypal.

Dennis: Apparently the case parts are coming slow boat from California. They shipped last Friday and they won't be here until this Friday. I don't have high hopes for it being a usable design though, I don't know much about building physical things and I'm sure that's going to be evident when none of the holes line up. That said, I'm getting enough parts to make 3 whole cases so I'm sure I'll be able to make one fit. I hope.
 
If it's all the same to you I'll just take two of your three board order (I'm gathering three is a minimal order).

Bryan Mayland said:
Jeff, given than my panel hasn't even been sent to fab yet, you can get in on that order and get 3 boards shipped directly to you rather than going through me if you want. The panel goes to fab tomorrow 9/13 so let me know if you'd rather do that and I'll refund your paypal.
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Bryan Mayland said:
Jeff, given than my panel hasn't even been sent to fab yet, you can get in on that order and get 3 boards shipped directly to you rather than going through me if you want. The panel goes to fab tomorrow 9/13 so let me know if you'd rather do that and I'll refund your paypal.

Dennis: Apparently the case parts are coming slow boat from California. They shipped last Friday and they won't be here until this Friday. I don't have high hopes for it being a usable design though, I don't know much about building physical things and I'm sure that's going to be evident when none of the holes line up. That said, I'm getting enough parts to make 3 whole cases so I'm sure I'll be able to make one fit. I hope.
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I have even less experience in building physical things. I guess I should start reading up on how to do it. Unless by some chance yours arrives and it is perfect first try :-)
 
Jeff Boardman said:
If it's all the same to you I'll just take two of your three board order (I'm gathering three is a minimal order).
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Yeah 3 is the min from OSH Park. It is no problem, I just thought I'd offer the alternative. The panel actually went to fab yesterday so I might get them a few days earlier!
 
Hi Bryan. The SMD board is almost ready for fabrication. I have done a lot of 3-D modeling which has allowed me to avoid a handful of potential clearance issues. One of which is the DC power jack. I decided last night that I will need modify DC power jack part in my eagle library to remove the hole for pin 2 (the outside pin). It forces the DC jack over too far which causes it to touch that little ribbon cable connector thing on the Pi. Pin 2 on the DC jack is a switch that is tied to ground and is on when the jack is unplugged. I think that switch is normally used in designs with both DC and battery power supplies and as far as I can tell is unnecessary in your schematic. Do you see any potential issues with doing that?

I am probably going to put in order in for the parts before I order the board since Mouser usually only takes a couple days to deliver. I need to make sure that I didn't mess up the holes and pads on the 2.5mm mono jack part I made in Eagle. I am going to print a scale copy of the board on printer paper and see if the real part lines up with the holes/pads.

My only other concern is how close the bottom of the LCD is to the top of the USB hub. I am thinking I will just squeak by. If not, it is back to the drawing board.

I should be finished up with the final draft this week. Would you mind taking a quick look at it for any errors? I know you are busy. If so, how should I send it? It is essentially the same board as yours but without the wireless probe option (I am still trying to figure out how to fit that!).
 
Yeah that DC jack pin is generally called the "spring" from what I've seen and it isn't used. I think I wired them both up to ground because I can never remember which pin is ground so having them both be ground is a no-brainer. It will be fine without that pin.

I also printed out several 1:1 copies from eagle to test sizes and measurements. It is definitely helpful. Are you concerned about a via on the back of the LCD shorting from the USB shield? You could always just put one of those felt feeties on the USB jack to insulate it. The annular ring around the LCD screw holes are also electrically isolated I believe so it won't make a difference if they touch.

I'd be happy to look it over, even if something would have to stick out pretty badly for me to see it as being wrong. Just zip up the brd/sch and email it to bmayland@leoninedev.com when you're ready.
 
Bryan Mayland said:
Yeah that DC jack pin is generally called the "spring" from what I've seen and it isn't used. I think I wired them both up to ground because I can never remember which pin is ground so having them both be ground is a no-brainer. It will be fine without that pin.

I also printed out several 1:1 copies from eagle to test sizes and measurements. It is definitely helpful. Are you concerned about a via on the back of the LCD shorting from the USB shield? You could always just put one of those felt feeties on the USB jack to insulate it. The annular ring around the LCD screw holes are also electrically isolated I believe so it won't make a difference if they touch.

I'd be happy to look it over, even if something would have to stick out pretty badly for me to see it as being wrong. Just zip up the brd/sch and email it to bmayland@leoninedev.com when you're ready.
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Okay I sent the board off to you to take a quick look. I took care to make sure none of the LCD "feet" touched any components. The 3-D model really helped with that. There is a potential issue with the hub and the LCD but I was thinking I would put tape on top of the USB hub (or felt).
 
Yeah I saw that. The performance gains are nice but they appear to strictly come from overclocking, which you can do now. Their "turbo" is actually reverse turbo, in that the CPU is throttled down when not in use, which lowers the temperature and provides more headroom when there is computation to do. I was actually wondering a few weeks ago if he SoC supported low power CPU states and "deep sleep" so I guess that answers that.

The USB interrupt rate fix is certainly interesting though.

There probably would not be any noticeable improvement in LinkMeter, and the process of pulling patches into the OpenWrt build is so tedious that getting this integrated is a really low priority.
 
Jeff Boardman said:
I sent you some PayPal cash for two boards when you get them. I'll start working on gathering the parts. I plan on getting both working then seeing if I can pot one in acryllic.
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Jeff, where are youuuuuuu? I've sent you an email and a PM but haven't heard anything. I don't have your address! Email / PM me your address so I can send you your boards.
 
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