RaspberryPi + LinkMeter blue sky discussion


 
Originally posted by RJ Riememsnider:
I know this is a Pi thread but has anyone looked at these?

http://gooseberry.atspace.co.uk/?page_id=13
Click to expand...
I actually had looked around at DealExtreme looking at AllWinner A10 CPU-based devices on the cheap after seeing this $74 Android stick. The cost is a little high but having built-in WiFi would really be nice. The only expandibility is over USB I think too, meaning you'd have to build to the Android peripheral spec. Not a big deal but a largely different thing.

Maybe by the time the Pi version is done, these things will be $35 and the size of a pack of gum, then we can make a USB plug that is a HeaterMeter or something.
 
Originally posted by Bryan Mayland:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RJ Riememsnider:
I know this is a Pi thread but has anyone looked at these?

http://gooseberry.atspace.co.uk/?page_id=13
Click to expand...
I actually had looked around at DealExtreme looking at AllWinner A10 CPU-based devices on the cheap after seeing this $74 Android stick. The cost is a little high but having built-in WiFi would really be nice. The only expandibility is over USB I think too, meaning you'd have to build to the Android peripheral spec. Not a big deal but a largely different thing.

Maybe by the time the Pi version is done, these things will be $35 and the size of a pack of gum, then we can make a USB plug that is a HeaterMeter or something. </div></BLOCKQUOTE>

Not sure about the others but that one I linked to can run Ubuntu. I'm not sure about it's GPIO capabilities though. Hopefully there will be lots of options soon.
 
Software is working flawlessly, recording data and drawing graphs without crashing. I've sort of hacked it right now to default to using DHCP instead of a static address, but I can work that out later.

I'm trying to get a first try board layout done before Monday, but I'm having a little trouble getting it all to not interfere with the stupid jacks, mostly the stupid composite RCA jack on the Pi.

Also, if someone can find rectangular connectors for connecting to the Pi's expansion header that are slightly longer than the standard length that would be pretty sweet. Something like this or this except instead of the height of the connector being ~8.5mm, we need about ~10.5mm or 11mm. Probably not a big deal but the connector doesn't go all the way down and I'd be concerned about not making good contact.
 
Originally posted by Bryan Mayland:
I'm having a little trouble getting it all to not interfere with the stupid jacks, mostly the stupid composite RCA jack on the Pi.

Also, if someone can find rectangular connectors for connecting to the Pi's expansion header that are slightly longer than the standard length that would be pretty sweet. Something like this or this except instead of the height of the connector being ~8.5mm, we need about ~10.5mm or 11mm. Probably not a big deal but the connector doesn't go all the way down and I'd be concerned about not making good contact.
Click to expand...

Told ya about those clearances
icon_smile.gif
I can upload my sketchup files if you want. I also have concerns with the lack of physical support for the heatermeter board on the HDMI side of the Pi. That could be mitigated if one could find a taller female pin header which would allow the board to sit on the LAN. I don't know of any female headers taller than 8.5mm and I have looked around a bit. That is why I suggested making a funky board that avoided the tall jacks. Problem with that is not enough space for the through-hole components.

I have to call Newark/Element 14 tomorrow to get an RMA number for my board. It seems the USB hub isn't functioning properly. Based on the Raspberry Pi forums, it is likely a soldering problem on the X1 crystal. I don't want to mess with trying to re-solder the crystal and voiding my warranty.

Would you mind sticking the working beta linkmeter image on the git so I can test it on my Pi? Perhaps it will let me SSH into the board.
 
Originally posted by Dave S (GeoDave):
I have to call Newark/Element 14 tomorrow to get an RMA number for my board. It seems the USB hub isn't functioning properly. Based on the Raspberry Pi forums, it is likely a soldering problem on the X1 crystal. I don't want to mess with trying to re-solder the crystal and voiding my warranty.

Would you mind sticking the working beta linkmeter image on the git so I can test it on my Pi? Perhaps it will let me SSH into the board.
Click to expand...
Oh man that sucks, especially because it will probably take a month to get a replacement. As far as the boar design goes, the LCD will rest on the ethernet jack I think and the LCD panel should be inside the box so there shouldn't be any pressure on it. I'm going to make space to screw standoffs into the heatermeter side which should provide support as well. We'll see if that is enough to hold things in place.

You can grab the test image here (openwrt-brcm2708-sdcard-vfat-ext4.img):
http://home.capnbry.net:22674/rpi/

Use either Linux `dd` or Win32DiskImager to write it to an SD card. It is 128MB because... well I'm not exactly sure because it is 2x 80MB partitions, one with 6MB in it and the other with 5MB in it. I haven't had a chance to work out how to get it down to 16MB total.
 
The board was sent up to Dorkbot yesterday and may be in Friday's panel.


It was ~$40 for the 3 boards ($13.27/ea). I might be able to shrink it down a bit but I don't think it would make a significant difference. The reason it is 30% more than the HeaterMeter for LinkMeter boards is the addition of the Alarm buzzer, 2 new LEDs, button board and probe/blower jack integration. It also has 3 holes for putting some screws in it. I know the silkscreen needs a lot of work but at least I'll be able to tell how everything is going to fit together and if anything needs to be moved.
 
Welp, my first problem is that I can no longer find those PCB-mount mono jacks anywhere. I can only find the 2-pin variety on mouser that has a different footprint and no "no input" pin. Wonderful!
 
Originally posted by Bryan Mayland:
Welp, my first problem is that I can no longer find those PCB-mount mono jacks anywhere. I can only find the 2-pin variety on mouser that has a different footprint and no "no input" pin. Wonderful!
Click to expand...

I bought a bunch (~50) pcb jacks. Let me see if i can find the specs......
 
Yeah those are similar to the ones I had seen at Mouser as well. Now I can't seem to find them at all even searching by part number. I think I might make the effort to switch the whole project over to Digi-Key's components considering they have a few 2.5mm jack possibilities. None that appear to match the footprint but I'll figure something out.

HOT GLUE AND JUMPER WIRES, YA'LL!
 
I have read through the linkmeter threads, and now this one. I love the idea of building my own controller but wonder what the differences/advantages are to this system vs. the linkmeter built into a router? Will this system eventually be more robust? Will it also have the wireless capabilities? I do not "need" a ATC unit right now so I could afford to wait some if you feel this is the direction to go for the future.
 
The advantages:
-- Speed: The LinkMeter U/I is ridiculously slow. Well mainly the OpenWrt configuration is really slow. The LinkMeter pages are somewhat quick. The Pi is anywhere from 2x-10x faster depending on the page (pages that are already fast show less improvement).
-- Storage: There's no storage on the Linksys without doing an SD card mod that doesn't work reliably and requires soldering to surface mount components. Storage is used to keep records of old cooks.
-- Size: The Pi+HeaterMeter board has a footprint of about 1/3 a WRT54GL
-- Reliability: The serial port in the Pi seem to be less troublesome than the WRT54GL because they're actually supported as a feature.
-- Build ease: The Pi won't (doesn't) require an ATmega with a bootloader, which can save considerable headache. Also all HeaterMeter components are integrated onto the mainboard which means you don't have to build wiring harnesses or attach external parts for the LCD, buttons, and jacks. Also you don't have to mess with tftp to flash firmwares which can be really frustrating if you're not experienced with it.
-- Expandibility: The Pi has a ton of RAM and storage, so some features might be too big for the LinkMeter be possible on the Pi.

Disadvantages:
-- Cost: The Pi can be more expensive depending on the cost of the router. You can get some routers for $20 shipped. The Pi is $35 shipped and will require a wifi dongle ($15-20+) and a power supply ($10?).
-- It isn't done yet. This may sound like not a problem but I'm targeting having it done for sure by the end of the year. That's a long way off!
 
One additional advantage that I see for the Raspberry Pi is that you can do other cool stuff with it! I hope to be able to just pop in a SD card for when I want to smoke, and then pop in a different one when it's connected to my TV. The router is more limited in purpose.
 
Well it sure seems to me that the advantages far outweigh the very few disadvantages, the main one probably being cost. That said it will still come in way under what a Stoker or similar would cost, and since I do not necessarily need it right now the wait part really is a non factor.

Thanks for all the info, I can not wait to see how this progresses, I may have to put in an order for a Pi just so I am ready as it progresses
 
Bryan,

Did you fix the fan output circuit to pull the bypass cap C1 to GND instead of the source side of Q1?

dave
 
Originally posted by Bryan Mayland:
Yeah those are similar to the ones I had seen at Mouser as well. Now I can't seem to find them at all even searching by part number. I think I might make the effort to switch the whole project over to Digi-Key's components considering they have a few 2.5mm jack possibilities. None that appear to match the footprint but I'll figure something out.

HOT GLUE AND JUMPER WIRES, YA'LL!
Click to expand...

You're welcome to what I have left. I have at least 20.
 
Thanks RJ but I think I've actually found another PCB issue that may require a change. The SPI driver always asserts !CE0 when communicating so it will cause the HeaterMeter to reset. I've got to make second version and I'll just redo the footprints to match what's available from DigiKey.
 
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