Version 2 of my homebrew controller


 
Originally posted by Bryan Mayland:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I compiled a list of digikey parts from bryan's parts list.
note qty's are for 2 or minimum purchase.
can someone proof-read list please.
Click to expand...
I didn't check the part numbers but the part are ok with the following changes:
-- You're missing the 1N914 signalling diode for the shift register latch
-- We originally used IRF510 MOSFETS but the proper part is an IRL510 MOSFET. The IRF is a 10v gate and the IRL is 5v.

Not that it saves a lot of money but the only 1% tolerance resistors you need are for the 22k ones. The rest you can get by with 5% carbon film resistors. Saves about, what, $2.40?

Finally, that perfboard you've got is continuous bus (all the holes on each row are connected). Don't know if that is intentional and you are going to cut the traces yourself. </div></BLOCKQUOTE>
15 2 IRL510PBF-ND MOSFET N-CH 100V 5.6A TO-220AB 0 1.36000 $2.72
16 2 1N914BCT-ND DIODE SS HI COND100V 200MA DO-35 0 0.16000 $0.32
I a picking components by the "Eny Meany Miney Mo" method using the Version 2 schematic. is D2 listed as 1N4004 suppose to be the 1N914.
I am debating on using continuous stripboard (Cut trace) or the Radio shack 3 hole 2 continuous pattern.
 
I've tried opening the top up, so the daisy is completely open but the lid is still slid shut. The temperature initially dropped as the hot air escaped but it came back up after a few minutes.

It is strange that you're seeing numbers for probes that aren't plugged in. Do your jacks have 3 "pins" on them? When the probe isn't inserted in the jack, the "tip" connector on mine comes up and touches a third piece that I have grounded. When there is nothing connected, it grounds tip so the reading from the ADC is 0 and the software stops showing that probe. You may want to look and see if you have something similar you can do.

Gerry: I'm sorry, I'm a total douche. You're right, the schematic-v2 has the wrong components in it. If you look at the one on the blog it has the right parts, I guess I didn't update the image in the bbq directory too. I've fixed schematic-v2.png. The freewheeling diode is also in the wrong spot on the old v2.

Note that if anyone (Ed) built it with the diode before the fan rather than in parallel with it, removing it will increase your fan speed by about 0.7V across the board. Something to watch out for if you change it.

EDIT: And yes, the probe offset is supposed to let you calibrate the probes, but I'm not sure how. It seemed like a good idea when I added it! I've put all three of mine in boiling water and they all read within a degree of each other so I've always just left my offsets at 0. Technically the probe offset is added to the read temperature (if the temperature is non-zero).
 
Originally posted by gerry m.:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Bryan Mayland:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I compiled a list of digikey parts from bryan's parts list.
note qty's are for 2 or minimum purchase.
can someone proof-read list please.
Click to expand...
I didn't check the part numbers but the part are ok with the following changes:
-- You're missing the 1N914 signalling diode for the shift register latch
-- We originally used IRF510 MOSFETS but the proper part is an IRL510 MOSFET. The IRF is a 10v gate and the IRL is 5v.

Not that it saves a lot of money but the only 1% tolerance resistors you need are for the 22k ones. The rest you can get by with 5% carbon film resistors. Saves about, what, $2.40?

Finally, that perfboard you've got is continuous bus (all the holes on each row are connected). Don't know if that is intentional and you are going to cut the traces yourself. </div></BLOCKQUOTE>
15 2 IRL510PBF-ND MOSFET N-CH 100V 5.6A TO-220AB 0 1.36000 $2.72
16 2 1N914BCT-ND DIODE SS HI COND100V 200MA DO-35 0 0.16000 $0.32
I a picking components by the "Eny Meany Miney Mo" method using the Version 2 schematic. is D2 listed as 1N4004 suppose to be the 1N914.
I am debating on using continuous stripboard (Cut trace) or the Radio shack 3 hole 2 continuous pattern. </div></BLOCKQUOTE>

Gerry,

I'm going over your parts list in detail now.

I'm confused on some of your quantities. For example, why 10 thermistors, 2 blowers, etc.?

Also, some of your prices are higher than I see them on the digikey site. For example, you had IRL510PBF-ND listed as $2.72 each, but I'm showing them as $1.51 each.

I'm refining the parts list based on Bryan's design with no extras so we can get an idea of the real cost to build just one of these.

Thanks,

John
 
Originally posted by John Mangan:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by gerry m.:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Bryan Mayland:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I compiled a list of digikey parts from bryan's parts list.
note qty's are for 2 or minimum purchase.
can someone proof-read list please.
Click to expand...
I didn't check the part numbers but the part are ok with the following changes:
-- You're missing the 1N914 signalling diode for the shift register latch
-- We originally used IRF510 MOSFETS but the proper part is an IRL510 MOSFET. The IRF is a 10v gate and the IRL is 5v.

Not that it saves a lot of money but the only 1% tolerance resistors you need are for the 22k ones. The rest you can get by with 5% carbon film resistors. Saves about, what, $2.40?

Finally, that perfboard you've got is continuous bus (all the holes on each row are connected). Don't know if that is intentional and you are going to cut the traces yourself. </div></BLOCKQUOTE>
15 2 IRL510PBF-ND MOSFET N-CH 100V 5.6A TO-220AB 0 1.36000 $2.72
16 2 1N914BCT-ND DIODE SS HI COND100V 200MA DO-35 0 0.16000 $0.32
I a picking components by the "Eny Meany Miney Mo" method using the Version 2 schematic. is D2 listed as 1N4004 suppose to be the 1N914.
I am debating on using continuous stripboard (Cut trace) or the Radio shack 3 hole 2 continuous pattern. </div></BLOCKQUOTE>

Gerry,

I'm going over your parts list in detail now.

I'm confused on some of your quantities. For example, why 10 thermistors, 2 blowers, etc.?

Also, some of your prices are higher than I see them on the digikey site. For example, you had IRL510PBF-ND listed as $2.72 each, but I'm showing them as $1.51 each.

I'm refining the parts list based on Bryan's design with no extras so we can get an idea of the real cost to build just one of these.

Thanks,

John </div></BLOCKQUOTE>
Thanks I know the difference between a resistor and a diode, but, after that all bets are off. My intention is to build two of these units one for me and one for my son, so the base qty was two, but some of the components have a min qty so those went to 10, also my lack of knowledge in picking components shows up in pretty bad like with the 1N914 there are dozens of them. also the formatting is hosed. the last number is amount times price. unit cost is right before.
 
Golly! I forgot to post this last week. I had been meaning to test it but haven't had any time.
HeaterMeter r39

-- Added MINIMUM_FAN_SPEED define
-- Added GrillPid::MaxFanSped member for max speed that can be set by automatic mode (in percent)
-- Will no skip Ambient temperature on home menu if no ambient probe is present
-- Will have blank second line if no non-pit probes are present

John Mangan: I've added a define for one thing, and the Max Speed is now a variable so maybe that can clear things up a bit. I'm not opposed to making things easier to understand, I just don't know how I can make it any clearer what's going on.
 
Originally posted by Bryan Mayland:
John Mangan: I've added a define for one thing, and the Max Speed is now a variable so maybe that can clear things up a bit. I'm not opposed to making things easier to understand, I just don't know how I can make it any clearer what's going on.
Click to expand...

Brian, that's perfect and all we need for easy adjustment.

FYI, I started building my circuit this weekend only to find that one of the parts I ordered from Digikey was incorrect. Uggh. So placing a new order to Digikey now. Also going to order a lot of the misc. items that Gerry identified. I already have most of them from Radio Shack, but I figure since I'm ordering and they are cheap, I might as well confirm the parts list is correct.

- John
 
Ok, I have a parts list that I think is fairly complete for this project. The only thing I haven't defined is the project enclosure. This parts list assumes that you have NOTHING to start with for parts. Total cost for the project comes in at $177.39. If you add shipping from the vendors, it will probably be closer to $200 when all is said and done.

HeaterMeter Parts List

PS: I'm also ordering a true PWM controlled fan to see if it can control the temp a bit better (easier) than the method that Bryan is currently using.

Gerry, thanks for your help in pulling this together.
- John
 
Originally posted by Ed Pinnell: Good job, John!!! But caramba! It's not that much less than the commercial units, not when you figure time and trouble, unless you count the time and trouble as entertainment, like we do...

Do you feel like doing a workup on a barebones version so people can have an upgrade path? Say, a single pit probe, no WiShield, etc.?

EDIT: Actually, I said good, but I meant to say OUTSTANDING! Thanks, John and Gerry!!!
Click to expand...

Thanks Ed!

I was thinking the same thing. Ideally I would like to get this project to be around $100 for materials. I can already think of a few areas to save on cost:

- Using the lower temp ET-73 food probes (saves $10)

- Using a YellowJacket (from AsyncLabs) in place of the Arduino and WiShield 2.0 (saves $29.95) - Not sure about memory and/or I/O limitations without looking into it more though.

- Using a lower-end 16x2 LCD display (could save ~ $7)

- Using a PWM fan with baffle vs. a blower (could save ~ $10)

So those changes alone would bring the project down by nearly $60. If we make a single food probe offering, that saves another $10.

I'll mock up a few versions of materials on that same spreadsheet. I'll use different tabs (seen down near bottom of sheet).

- John
 
Originally posted by Ed Pinnell:
Another thought that is probably 'way out there...and I'm not 100% certain it will work, but for the life of me I can't see any reason why it wouldn't work, so if I'm wrong somebody say so...but if a guy were to build this project without hardware dependencies like a WiShield or a ProtoShield, what would keep him from pulling the Atmel MCU from the Arduino after loading Bryan's software and transplanting it into a standalone board with the appropriate support chips, and upon replacing the Atmel chip, preserve the Arduino development platform? So that the cost of the Arduino Deumilanove becomes pretty much a one-time expense and the true cost of the uController part of the project is the cost of the chip and supporting chips...

EDIT: Ok, to answer my own question, the Arduino uController has a bootloader that enables it to become both a programmer as well as being able to run programs. At the end of the Arduino is a 6-pin ICSP header (in-circuit serial programmer), which I assume also allows it to program other, similar Atmel uControllers. The bootloader isn't necessary to run this program, and leaving the bootloader out frees up another 2k of program space, so a guy could keep the Arduino for a programmer and make some temporary connections to an unprogrammed chip to transfer the program. Have I got this right?? BTW, I have several AVR programmers I've bought and/or built over the years, so my brain might be fried...
Click to expand...

Ed, definitely not way out there and worth looking further into. I think I recall Bryan saying he built an Arduino from the ground up with just piece-parts and a breadboard. If not Bryan, I know others have done it. My guess is that we could probably get that part down around $8-10.

The WiShield on the other hand might be a bit more difficult. If we want to assume that the builder has a spare WRT54G router laying around that would be one thing. But if we want to define an "all inclusive kit" (which I think is what many people want), we might as well stick with the WiShield or try to use the YellowJacket which combines both Arduino and WiShield in 1.

- John
 
Hi guys,

Would the BlackWidow work for this project. I'm quite new to electronics but i'm curious if there would be enough pins left over to still use an LCD display and 2-3 probes as it looks like the wifi takes up an awful pile of pins on that setup

Thanks
Andrew
 
Originally posted by Andrew Smith:
Hi guys,

Would the BlackWidow work for this project. I'm quite new to electronics but i'm curious if there would be enough pins left over to still use an LCD display and 2-3 probes as it looks like the wifi takes up an awful pile of pins on that setup

Thanks
Andrew
Click to expand...

It looks like the BlackWidow would work (we need 14 digital I/O pins which it has), but unfortunately at $75 ea., that won't do anything to help us keep the costs down.

- John
 
Originally posted by John Mangan:
Ed, definitely not way out there and worth looking further into. I think I recall Bryan saying he built an Arduino from the ground up with just piece-parts and a breadboard. If not Bryan, I know others have done it. My guess is that we could probably get that part down around $8-10.
Click to expand...
Yeah I built a test Arduino platform just out of parts, with no USB connector, for $10. That includes the DC barrel jack and some headers. It has the standard 6 pin ICSP and the FTDI breakout for programming. I also had to use my main Arduino to flash the chip because it came without a bootloader. The Arduinos from Sparkfun already have the bootloader but cost like 50 cents more. You can also get cheaper LCDs from Mouser/Digikey, around $10-12.

The real way you can save is if you already have the probes from an existing thermometer, that's like $40 right there. Build it sans WiFi and you're down to under $100 I reckon.

I've probably spent over $1000 on my HeaterMeter, if you include the PCB vise, oscilloscope, test leads, hookup wire, dremmel (for cutting the case), etc. I never get to make anything as a programmer though, so this was pretty exciting for me. Plus I enjoy knowing that I can change any aspect of it because I have the source code!

One thing I would like to change though is that I'd prefer it have some sort of alarm beeper. My worst fear is that I'll run out of fuel in the middle of the night and wake up to a cold grill. You can detect when this condition is occurring, the fan average is 90%+ and the temperature is at [lid offset] and dropping.
 
Bryan,

On a somewhat related note, do you have any code working for sending tweets to twitter from the Arduino with Wishield?

They changed their API a couple months ago and it broke a lot of example code that is already out there. I figure if anyone could figure it out, you could!
icon_smile.gif


More info on the problems we're having here:
http://tinyurl.com/2dvkovc

I would eventually like to build in an optional twitter alert mechanism that I can monitor from my phone (and do other useless things).

- John
 
Originally posted by Bryan Mayland:
You can also get cheaper LCDs from Mouser/Digikey, around $10-12.
Click to expand...

I found one from Digikey for $7.79 that I've listed in my "low cost" parts list (on the spreadsheet posted above).

It can be seen HERE. I haven't read over the specs closely yet though.

The real way you can save is if you already have the probes from an existing thermometer, that's like $40 right there. Build it sans WiFi and you're down to under $100 I reckon.
Click to expand...

Yea, I agree, and I think many of us will already have the probes (and possibly the Arduino's). As part of building the Instrucable for this though, I'm trying to come up with a comprehensive list of materials the represents that total cost to build assuming you have nothing to start with.

I've probably spent over $1000 on my HeaterMeter, if you include the PCB vise, oscilloscope, test leads, hookup wire, dremmel (for cutting the case), etc. I never get to make anything as a programmer though, so this was pretty exciting for me. Plus I enjoy knowing that I can change any aspect of it because I have the source code!
Click to expand...

Agreed. I already had many of the parts required for this build, but I've easily put $150 in to it thus far (on top of what I had).

On the bright side, all this initial leg-work and expense for getting the first few revisions solidified so it can be repeatably built is going to make a lot of others that follow us very happy. We need a Paypal account for donations. Lol.

One thing I would like to change though is that I'd prefer it have some sort of alarm beeper. My worst fear is that I'll run out of fuel in the middle of the night and wake up to a cold grill. You can detect when this condition is occurring, the fan average is 90%+ and the temperature is at [lid offset] and dropping.
Click to expand...

I totally agree. I'm not sure if you've had a chance to review the draft Instructable that I started creating but I had several different alarms that I would like to have added in later revisions.

- John
 
On a somewhat related note, do you have any code working for sending tweets to twitter from the Arduino with Wishield?
Click to expand...
Twitter is for jerks!

No I've never looked at using twitter. I've spent about 2 minutes in my entire life on the twitter website. I'm not a fan, but I do recognize the decided lack of ability to send short messages from devices to users. I wish there were a better way though. The 29k of code we have so far does include the TCP/IP client code though. (Wow 29k? when did we go over 29k?)

I didn't notice the LCD was different in the low cost version of your parts list. The one you link there doesn't have a backlight, which is fine, but that means you don't need the 6.8R resistor either (which is used to current limit the backlight). 9 cents baby!
 
Originally posted by Bryan Mayland:
Twitter is for jerks!

No I've never looked at using twitter. I've spent about 2 minutes in my entire life on the twitter website. I'm not a fan, but I do recognize the decided lack of ability to send short messages from devices to users.
Click to expand...

Lol! I'm with ya, but this would finally make it useful for something other than being a soapbox. How twitter ever caught on is beyond me. Might as well make use of the infrastructure they have in place. They don't seem to be going anywhere anytime soon.

I'll update the low-cost part's list and remove the resistors. Thanks for checking into that.

- John
 
Originally posted by Ed Pinnell:
At 29k, it seems like the Arduino is close to running out of program space. If it becomes necessary to go up to the next Arduino level, will the WiShield still be compatible?
Click to expand...

Yes, the Arduino Mega is compatible with the WiShield 2, although I haven't tried it yet (I do have Mega to try it on later).

- John
 
Originally posted by John Mangan:
Will this thermistor work in place of this one?
Click to expand...
Yeah any NTC thermistor should work. You should be ok with that one, the only thing I'd be wary of is the fact that the leads are polyurethane coated except the the last little bit. I don't imagine you'll have a problem scraping it off to solder though, or you can just leave it extending up from the breadboard.

Either way you'll still have to recalculate the ABC coefficients for the Steinhart-Hart equation. I think I used the STEIN3.EXE least squares curve fitting algorithm. The app is 16-bit so have fun if you're on Win7 x64!
 
FYI, just waiting on a few parts to arrive. I'll hopefully be able to begin (and finish) assembly this weekend.

I also have a "Netduino" on the way. Can't wait to experiment with that too!
 
You must log in or register to reply here.

 

Back
Top