HM V5? Total cost to build HM?


 
M

MattBarga

New member
Guys,

I've stumbled on this forum after initially looking to build a PID controller. Wow, this thing is amazing. Thank God my dad is an electrical engineer, and is handy soldering.

I have 2 questions before I decide to go and do this:

1) Bryan--I saw in some posts some discussion about adding capacitors on the thermistor inputs and some others. That got me thinking and wondering if there was a HM V5 on the horizon from a hardware perspective? HM 4 has been out since September, and the last thing I want to do is order all my parts only to see my work obsoleted in a few weeks/months. If you could share your thoughts about the future (on the HW side, the Todo list shows SW future)

2) Total Cost: How much has it costed people to build this? When I add in component costs, shipping, case, probes, etc I see that the total cost would be up around $190 or so. Is that in the ballpark or am I way over/under? Just want to get some input based on other people's experiences.

Thanks in advance.

Matt
 
Here are my rough numbers:
case 25
probes 3x15 = 45
board 12
pi 45
mouser 30
Wireless 10
Digikey $19+ $5 shipping

total $192

This assumes you already have a power supply, so $190 looks like a good number.

dave

Added Digikey
 
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1) I just have some ideas kicking around in my head for a future design, but that probably won't happen for months if at all. It will be a 4.1 design more than anything else. V1 and V2 were just the first two I made, then V3 was for the WRT54GL, and V4 is the RasbperryPi. It seems to be a pretty good platform to build off of, so I think I'll be sticking with it indefinitely.

2) You're looking at $75 for the PCB and parts, $30 for a case, $10 power supply, $45 RasberryPy, $10 Wifi, $5 SD card = $175. 4 probes would be about $40 on top of that, and you also need a way of mounting the blower, and a piece of RCA cable to wire it. I still use my cardboard blower mount, although I now have to duct tape it to the grill every time I use it. :(

EDIT: I am bad at math.
 
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Brian--

Any signficant changes for the 4.1? Or will we be able to re-work the 4.0s?

Also, I'm interested in a 4 line display. Can you provide requirements/specifications or even better, suggest 1 or 2 off Mouser/Digikey?

Thanks!
 
I have a 4 line display working just fine. There is currently no 3d printed case available for the 4 line though but it is being worked on. So if you want the 4 line you will either need to make a case yourself or wait until one is perfected.

Here are some displays from mouser. eBay has a ton as well, make sure you get one of the 98x60mm ones that has a parallel interface.
http://www.mouser.com/ProductDetail...=sGAEpiMZZMt7dcPGmvnkBuTSa0afjlx9bQvQ50RK4P8=
http://www.mouser.com/ProductDetail...=sGAEpiMZZMt7dcPGmvnkBg1FtbAhMMAHUBL/pLmAxLE=
http://www.mouser.com/ProductDetail...=sGAEpiMZZMt7dcPGmvnkBn9wAaQRCMdA63xTqyGIoF0=

Just let me know if you find something you like and want me to see if it would work.
 
So far the only ideas I have for the 4.1 board is:
-- Reorient the power and blower connectors in a way that leaves the bottom clear.
-- Replace the rca blower connector with a 2.5mm barrel jack
Possible ideas:
-- Possibly (after much testing) see if the caps on the probe inputs does anything to help or hinder probe accuracy
-- I'd like to do digital contrast control but we've only got 1 pin left sooooooo

But nothing that breaks a 4.0 or even a 3.0 or a 2.0 or a 1.0 board (even if I'm the only person who has a 1.0 or 2.0). In a few months I was going to call for suggestions and see if there were any better ideas.

This is the Varitronix 20x4 LCD I use, but only because I got them at super discount on eBay. They were cheaper a few months ago and I got 4 for $30 shipped. Still a great deal.
 
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RJ Riememsnider said:
I have a 4 line display working just fine. There is currently no 3d printed case available for the 4 line though but it is being worked on. So if you want the 4 line you will either need to make a case yourself or wait until one is perfected.

Here are some displays from mouser. eBay has a ton as well, make sure you get one of the 98x60mm ones that has a parallel interface.
http://www.mouser.com/ProductDetail...=sGAEpiMZZMt7dcPGmvnkBuTSa0afjlx9bQvQ50RK4P8=
http://www.mouser.com/ProductDetail...=sGAEpiMZZMt7dcPGmvnkBg1FtbAhMMAHUBL/pLmAxLE=
http://www.mouser.com/ProductDetail...=sGAEpiMZZMt7dcPGmvnkBn9wAaQRCMdA63xTqyGIoF0=

Just let me know if you find something you like and want me to see if it would work.
Click to expand...

Just to clarify... if I were to use one of the 4-line displays, I would have to then use a ribbon cable to keep the display on the 'top half' of the whole HM/RPi? If so, does it matter which way the cable is connected, or would I have to give it a 1/2 twist? ... that would then add an extra couple bucks to the build (+ the new or different enclosure to accommodate the larger screen)
 
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No twist, it's straight through. I currently am using an old ATA cable that I cut the long run off so it's about 6" long. Of course you could also just solder wires to connect the display or you could just use something like this from Adafruit.
 
RJ Riememsnider said:
I have a 4 line display working just fine. There is currently no 3d printed case available for the 4 line though but it is being worked on. So if you want the 4 line you will either need to make a case yourself or wait until one is perfected.

Here are some displays from mouser. eBay has a ton as well, make sure you get one of the 98x60mm ones that has a parallel interface.
http://www.mouser.com/ProductDetail...=sGAEpiMZZMt7dcPGmvnkBuTSa0afjlx9bQvQ50RK4P8=
http://www.mouser.com/ProductDetail...=sGAEpiMZZMt7dcPGmvnkBg1FtbAhMMAHUBL/pLmAxLE=
http://www.mouser.com/ProductDetail...=sGAEpiMZZMt7dcPGmvnkBn9wAaQRCMdA63xTqyGIoF0=

Just let me know if you find something you like and want me to see if it would work.
Click to expand...

RJ:

How about these 2? Will they work? One is 16x2, one is 20x4. Going to buy both.

http://www.ebay.com/itm/121029885443?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
http://www.ebay.com/itm/1pcs-16x2-1...695?pt=LH_DefaultDomain_0&hash=item19d53040af



Matt
 
MattBarga said:
RJ:

How about these 2? Will they work? One is 16x2, one is 20x4. Going to buy both.

http://www.ebay.com/itm/121029885443?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
http://www.ebay.com/itm/1pcs-16x2-1...695?pt=LH_DefaultDomain_0&hash=item19d53040af



Matt
Click to expand...

The 20x4 looks fine but if you want to mount the 16x2 directly on top of the HM as in Bryan's design, it needs the connecters at the bottom of the substrate and the top like this. Of course you'll need to find a display that has the colors you like but that should show you what I mean.

Hey, I just noticed you're in Charlotte, I'm in Greenville, SC.
 
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RJ,

Yes, I'm in Charlotte. Actually, was back in Greenville, SC area this past weekend visiting family in the area.

I've placed my OSH order, Amazon order (Pi and WiFi), Digikey, and Maverick Orders. Down to Mouser. Finding 2 parts on backorder:

653-B32-1610 Switch cap. Can I use the square one?
http://www.mouser.com/ProductDetail...wGy1pbX9hpSGIzKezvIUacN5%2bFCuhNjpogdop5w7w==

Would that interfere with the printed cases?

Some caps are also backordered.
Multilayer Ceramic Capacitors MLCC - Leaded 0.1uF 50volts 10% X7R 2.5mm LS

Is this one a substitute?
http://www.mouser.com/ProductDetail...=sGAEpiMZZMuAYrNc52CMZJzM8ei14SMU2jk1BPjyxdc=


And finally, I'm not going to mess with ordering a LCD from China, nor a 20x4. I want the slick case and 16x2 should be fine. Is this alternate to the recommended LCD OK:

http://www.mouser.com/ProductDetail...AMwvXmnNcIgthyO5MtQi5nNk6YhAVOuS4tuj8HrgC1ra4

Thanks for all of your help!

Matt
 
-- The square is ok apparently, as there is a case design with a square button hole! Just make sure you specify when requesting it.
-- Capacitor looks like it should be fine. It is the kind with outside kinked leads, which worst case you can just bend then straight. I'm not sure why a design would favor kinked leads over just straight ones but I guess they're something people use
-- Both the LCDs you linked are transmissive, meaning they require backlight. The FSTN positive means the letters are "white" and the background is blue, negative means the letters are blue and the background is black. EDIT: I don't know if there's a Blue/Black transreflective display in the right size.
 
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Bryan Mayland said:
-- The square is ok apparently, as there is a case design with a square button hole! Just make sure you specify when requesting it.
-- Capacitor looks like it should be fine. It is the kind with outside kinked leads, which worst case you can just bend then straight. I'm not sure why a design would favor kinked leads over just straight ones but I guess they're something people use
-- Both the LCDs you linked are transmissive, meaning they require backlight. The FSTN positive means the letters are "white" and the background is blue, negative means the letters are blue and the background is black. The blue one you can read in sunlight (transreflective) is model NHD-0216SZ-FSB-GBW. It has black letters on a grayish background which light up blue with the backlight.
Click to expand...

Is there another alternate capacitor you recommend?
 
Yeah the linked one is fine. I haven't had to ever look for a replacement part because they were so cheap if you bought 100, so I bought 100! That was 2 years ago and I'm about halfway through the bag. I have a lot of bags like that. Oh 30% off if I buy 10? Well give me 10! And I still have 9.
 
Bryan Mayland said:
Yeah the linked one is fine. I haven't had to ever look for a replacement part because they were so cheap if you bought 100, so I bought 100! That was 2 years ago and I'm about halfway through the bag. I have a lot of bags like that. Oh 30% off if I buy 10? Well give me 10! And I still have 9.
Click to expand...

Um, you could sell parts kits.... Give you a little cash and could be cheaper or the same we get through Mouser. I'd buy to try to help give back.
 
I thought about it at one point, but I looked at the parts list and it would take the cost down from like $75 to $70 so basically it would be a break even proposition and I'd have at least $700 in parts sitting in inventory. Then I'd also need little shipping boxes, bags for parts, have to do the work of making kits, dealing with the possibility that a part might be bad and having to mail out a replacement, plus the time. In the end it would cost the same and be more work for me, so bump that!

Most the parts I have 9 or 10 of are like I2C port expanders, differential comparators, way-wrong capacitors, 3.3V 3A regulators in TO-220 package, and a whole lotta junk I got when I didn't know exactly what all the stats in the datasheet meant.
 
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Bryan Mayland said:
-- The square is ok apparently, as there is a case design with a square button hole! Just make sure you specify when requesting it.
-- Capacitor looks like it should be fine. It is the kind with outside kinked leads, which worst case you can just bend then straight. I'm not sure why a design would favor kinked leads over just straight ones but I guess they're something people use
-- Both the LCDs you linked are transmissive, meaning they require backlight. The FSTN positive means the letters are "white" and the background is blue, negative means the letters are blue and the background is black. The blue one you can read in sunlight (transreflective) is model NHD-0216SZ-FSB-GBW. It has black letters on a grayish background which light up blue with the backlight.
Click to expand...

Bryan,

Please forgive me being a NOOB.

What is the difference between this one, which is FSTN positive and the one you referred that is STN? The pictures of the FSTN appear to show more contrast a crisper view. Please educate me and let me know if this one will work.
http://www.mouser.com/ProductDetail...%2bov0i2rLoaj0kJ03dOPPI4iC4xw5yIoeL7QLPnEBshv


Regards,

Matt
 
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