LinkMeter v2 Homebrew BBQ Controller - Part 1

[D Peart]

Bryan, I'm interested in your V4.0 board. My next project is to convert one of the temp probes to a humidity sensor. I then want to use that to control a SSR to turn on/off a humidifier. My goal is to control both temp and humidity for making salami. If you are freeing up an output that should allow me to do this.

Looking forward to see your update.

dave

 

[Dave S (GeoDave)]

Sooo...I come home from my vacation and the middle and bottom sections of my Weber Smokey Mountain and my custom blower had been stolen from my back yard!!! Who takes pieces of a smoker!?! Guess it will be a while until I get to use my linkmeter again

GRRRR!!!

 

[D Peart]

Oh man, that truly sucks! Sorry to hear it.

dave

Originally posted by Dave S (GeoDave):
Sooo...I come home from my vacation and the middle and bottom sections of my Weber Smokey Mountain and my custom blower had been stolen from my back yard!!! Who takes pieces of a smoker!?! Guess it will be a while until I get to use my linkmeter again

GRRRR!!!

 

[Bryan Mayland]

Originally posted by Dave S (GeoDave):
Sooo...I come home from my vacation and the middle and bottom sections of my Weber Smokey Mountain and my custom blower had been stolen from my back yard!!! Who takes pieces of a smoker!?! Guess it will be a while until I get to use my linkmeter again

GRRRR!!!

You have got to be kidding me. There are a bunch of savages in this world, I tell ya. I used to have a Jeep Wrangler, which has locks on the doors but the windows had zippers so I'm not sure what the locks were for. Anyway, I'd lose 1 or 2 of the 12V cigarette lighters a year because people would just steal them. That and the less-than-a-dollar's worth of spare change. It just makes you wonder what is wrong with people.

@D Peart:
I hadn't worked out the schematic yet, I've just been messing around with it as far as writing the software and testing it out on a breadboard. Really the plan was to make it 100% reliable so that nobody will have the garbled or blank LCD problem again, but there's still one thing I'm not totally happy with. I'd hate to make this change only to find that it is just as problematic as before. In any case, I'm going to tag the V3.1 board in git and make a zip package with the cam job already run for dorkbot so we'll have them for posterity then push the schematic up to github this weekend. I'm thinking of holding off on V4.0 entirely until the Raspberry Pi comes out.

For those who don't follow SoC development, Raspberry Pi is basically a board with a similar CPU to what's in the router, except 3.5x the speed, with 8x the RAM, USB, and an SD card slot built in. All of this will be for sale for $25. It doesn't have WiFi but it does support USB dongles which can be had for under $10. It hasn't been released yet but I wanted to check one out as a possible replacement for the Linksys altogether.

Also it is the size of a business card and has HDMI out. Yes HDMI. It has the same guts as what is inside a Roku 2 to give you the idea of how much power it has.

Maybe there we can do a 4.0 board then 5.0 could be the new platform? Does anyone mind? V3.1s would obviously be still supported.

 

[Bryan Mayland]

Oh also this weekend after the push Arduino 1.0 will be the build platform, HeaterMeter will not compile with 0022 any longer. I figure I can't fight progress even if it does bloat the code and RAM a little.

 

[Joe Loyd]

Originally posted by D Peart:
The first things I would do:

1. make sure the shift register is installed correctly.
2. If you have a volt meter ohm out all the traces from the AVR to the shift register to make sure they are all connected
3. check the wiring connections between the LCD and the header on the HM board
4. Use a voltmeter to test that everything is getting power

To see if the serial interface is working:

1. telnet onto the router, you may need to use ssh if you set the password, because telnet will be disabled. You cannot telnet in as root, because by default OpenWRT doesn't allow root access to the WAN. At least that is my theory why ssh doesn't work for root.
2. type 'cat /dev/ttyS1' without the quotes.

You should see something being displayed every few seconds.

OK, confirmed the LM's correct and ohm'd each line and checked the power pins (4.93V). Everything seems OK there.
On the serial part though it seems I'm stuck in password hell. Telnet is disabled and I can't login via ssh due to no password being set yet. Luci says there's no root password set and resetting it doesn't seem to have any effect. I see on the OpenWRT forum there was a suspiciously similar issue(LUCI password behavior is broken after updating to 28940.)like this. I used the snapshot from Github to flash the router, is it possible that's it's missing the referenced dependency?

 

[D Peart]

Joe,
I only know of two ways to work around that issue.

1. don't ever set a password. It isn't needed.
2. create a non root user then you can ssh into the router as that user.

The way I do it is.

1. flash router
2. telnet into router
3. set the password for root.
4. vi /etc/passwd and do the following
5. duplicate the root password entry
6. change the root user name in the newly created entry, to whatever you want to use. I used dave for obvious reasons

7. ssh into the router and use the newly created user name (dave in my case) with the password you set for root to verify you can ssh in.

You have to do this all within the original telnet session. After you log out, telnet will be disabled, and you will not be able to get back in.

I think this all happens because we bind the wireless interface to the WAN interface in the network setup and OpenWRT does not allow ssh into the WAN interface for security reasons.

dave

Originally posted by Joe Loyd:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by D Peart:
The first things I would do:

1. make sure the shift register is installed correctly.
2. If you have a volt meter ohm out all the traces from the AVR to the shift register to make sure they are all connected
3. check the wiring connections between the LCD and the header on the HM board
4. Use a voltmeter to test that everything is getting power

To see if the serial interface is working:

1. telnet onto the router, you may need to use ssh if you set the password, because telnet will be disabled. You cannot telnet in as root, because by default OpenWRT doesn't allow root access to the WAN. At least that is my theory why ssh doesn't work for root.
2. type 'cat /dev/ttyS1' without the quotes.

You should see something being displayed every few seconds.

OK, confirmed the LM's correct and ohm'd each line and checked the power pins (4.93V). Everything seems OK there.
On the serial part though it seems I'm stuck in password hell. Telnet is disabled and I can't login via ssh due to no password being set yet. Luci says there's no root password set and resetting it doesn't seem to have any effect. I see on the OpenWRT forum there was a suspiciously similar issue(LUCI password behavior is broken after updating to 28940.)like this. I used the snapshot from Github to flash the router, is it possible that's it's missing the referenced dependency? </div></BLOCKQUOTE>

 

[Bryan Mayland]

Originally posted by Joe Loyd:
I see on the OpenWRT forum there was a suspiciously similar issue(LUCI password behavior is broken after updating to 28940.)like this.

This is possible, our busybox isn't built with shadow support. I would give it a try except I've switched over to Backfire 10.03.1 to build as the default platform but it didn't build and I haven't looked into why. It wasn't something obvious so I put it aside. I'll see if the shadow support fixes the login issue. I just run with no password because I am lazy.

 

[Dave S (GeoDave)]

Originally posted by Bryan Mayland:
You have got to be kidding me. There are a bunch of savages in this world, I tell ya.

For those who don't follow SoC development, Raspberry Pi is basically a board with a similar CPU to what's in the router, except 3.5x the speed, with 8x the RAM, USB, and an SD card slot built in. All of this will be for sale for $25. It doesn't have WiFi but it does support USB dongles which can be had for under $10. It hasn't been released yet but I wanted to check one out as a possible replacement for the Linksys altogether.

Also it is the size of a business card and has HDMI out. Yes HDMI. It has the same guts as what is inside a Roku 2 to give you the idea of how much power it has.

Maybe there we can do a 4.0 board then 5.0 could be the new platform? Does anyone mind? V3.1s would obviously be still supported.

I talked to Weber and my insurance company today. They both said that it is actually pretty common for thieves to steal parts of smokers. I guess they are heavy and hard to carry so they come back multiple times. Luckily I have a pretty low deductible on my insurance. They agreed to pay me $269 dollars after the $250 deductible. The only probably is that the WSM 18.5" jumped from $250-$299 on Amazon and I have to remake my **** blower mount. Also, I just got finished seasoning the smoker. In the case someone doesn't know this, it takes 4-5 smokes to break in a WSM. You will notice the WSM running hotter than expected on the first few runs. No it is not the Linkmeters fault. Just make sure you fill the water pan to within a half inch or so of the top!

WOW!!! Love the Rasberry Pi. I am on board 100% on moving to the Rasberry! I am assuming that the heatmeter board would still be necessary or would/could you use the GPIO pins for the blower/probes? The PID controller would then need to be written in some type of linux program...right? You would still need a separate board for the probe and blower jacks, resistors, transistors, etc. I guess you would also have to either write a standalone Linkmeter program or setup a server to run the existing jQuery based Linkmeter code. What were you thinking?

I am down but not out. More...more!

 

[Bryan Mayland]

Originally posted by Kyle Christensen:
I have been scouring the internet for pictures of completed v3.1 setups to work off of, but haven't seen much of anything. I'd be much obliged if some wouldn't mind snapping some pictures of the guts of theirs next time they had it apart.

I've uploaded some new photos to my picasa HeaterMeter album. If there's something you're specifically looking for, let me know and I'll see what I can do.

 

[Joe Loyd]

Originally posted by D Peart:
Joe,
I only know of two ways to work around that issue.

1. don't ever set a password. It isn't needed.
2. create a non root user then you can ssh into the router as that user.

The way I do it is.

1. flash router
2. telnet into router
3. set the password for root.
4. vi /etc/passwd and do the following
5. duplicate the root password entry
6. change the root user name in the newly created entry, to whatever you want to use. I used dave for obvious reasons

7. ssh into the router and use the newly created user name (dave in my case) with the password you set for root to verify you can ssh in.

You have to do this all within the original telnet session. After you log out, telnet will be disabled, and you will not be able to get back in.

I think this all happens because we bind the wireless interface to the WAN interface in the network setup and OpenWRT does not allow ssh into the WAN interface for security reasons.

dave

....

To see if the serial interface is working:

1. telnet onto the router, you may need to use ssh if you set the password, because telnet will be disabled. You cannot telnet in as root, because by default OpenWRT doesn't allow root access to the WAN. At least that is my theory why ssh doesn't work for root.
2. type 'cat /dev/ttyS1' without the quotes.

You should see something being displayed every few seconds.

Thanks Dave, I reflashed and created the secondary account per your instructions. I can now shell in (!) but there's nothing showing up on ttyS1?

 

[Bryan Mayland]

Originally posted by Joe Loyd:
I can now shell in (!) but there's nothing showing up on ttyS1?

Just to be sure, you did populate R2 and R21 correct? You also might want to try removing the HM board and tying the router's RX/TX pins together and seeing if they work just to make sure you're not banging your head against the wall.
-- Place a jumper or piece of wire between the router RX/TX
-- Stop lucid `/etc/init.d/lucid stop`
-- `cat /dev/ttyS1`
-- Open a second connection to the router via telnet / ssh and `echo xxxx > /dev/ttyS1`
you should see xxxx appear on the first shell window

 

[Joe Loyd]

Originally posted by Bryan Mayland:

Just to be sure, you did populate R2 and R21 correct? You also might want to try removing the HM board and tying the router's RX/TX pins together and seeing if they work just to make sure you're not banging your head against the wall.
-- Place a jumper or piece of wire between the router RX/TX
-- Stop lucid `/etc/init.d/lucid stop`
-- `cat /dev/ttyS1`
-- Open a second connection to the router via telnet / ssh and `echo xxxx > /dev/ttyS1`
you should see xxxx appear on the first shell window

Confirmed R2 and R21 values but it looks like the serial port is dead....

 

[Bryan Mayland]

Originally posted by Bryan Mayland:
This is possible, our busybox isn't built with shadow support. I would give it a try except I've switched over to Backfire 10.03.1 to build as the default platform but it didn't build and I haven't looked into why. It wasn't something obvious so I put it aside. I'll see if the shadow support fixes the login issue. I just run with no password because I am lazy.

Oh sweet babies, after spending hours and hours trying to figure out why 10.03.1 wouldn't build (some of the crosscompile tools would fail when running make but not if you configured them directly), I found that the Ubuntu terminal wrapper "byobu" breaks the OpenWrt build. It sets something in the environment when it is running. It adds about 100KB of garbage to the environment though so there's not telling what causes it, but here's a tip for anyone trying to build OpenWrt on Ubuntu: don't use "byobu terminal".

Ah maybe I can actually do something now.

 

[Jay Bremner]

OK, couple of questions for anyone who wants to answer

1) I remember seeing a thread on here showing the different version of Linksys WRT54G routers (for using in this application) and now, through all my searches, I cannot find it. I picked up a Version 6 yesterday with High-Gain antennas and am wondering if there is anything different I need to do or just follow the Wiki?

2) Does anyone have an extra circuit board they would want to sell? If not, is there anyone who wants to go in on an order with me?

Thanks for all your support...you guys are incredible!!

 

[D Peart]

Any idea why the router would not want to re-load the linkmeter-wrt54g-squashfs.bin file now?

When I try it, the same file I have installed on it, I get a message "The uploaded image file does not contain a supported format. Make sure that you choose the generic image format for your platform."

Thought I'd ask before flashing via tftp.

dave

 

[D Peart]

Bryan,

Got a question for you.

Something weird has happened to me. Everything was working, I ordered my final ET-732 probe, got it today, tested it with the ohm meter and it looks good. I plug it into the HM and it reads 8032 which is right at 73 degrees, but HM reads -2 degrees.

Upon further debug, when I print out the Steinhart values the B, C, and R values are no longer getting set.

If I run:
pc0=1.2345e-4,2.3456e-4,3.4567e-8,1.5e4

and then print out the Steinhart values to ttyS1 per:
Serial.print(" P=");Serial.print(_probeType,DEC);Serial.print(" O=");Serial.print(Offset,DEC);
Serial.print(" A=");Serial.print(Steinhart[0],8);Serial.print(" B=");Serial.print(Steinhart[1],8);
Serial.print(" C=");Serial.print(Steinhart[2],10);Serial.print(" R=");Serial.println(Steinhart[3],8);

Thanks for the print statements in the code. I get:
P=1 O=0 A=0.00012345 B=0.00023697 C=0.00000013 R=10000.00000000

as you can see B, C, and R did not change. I do see A change.

Ideas?

UPDATE: echo '/set?pc0=5.36924e-4,1.91396e-4,6.60399e-8,2.2e4' > /dev/tt
yS1

works just fine. So it does seem to be a linkmeter issue.

UPDATE2: after seeing it was a linkmeter issue, I remembered you posted an updated ipk some while back. I installed it on my second HM, but not this one DOH! After installing it is all working now. Sorry for the confusion.

thanks,
dave

 

[M Rochford]

When putting in the resistance of your resistors are you just saying 10k or you putting in a avg of the all the resistors?

 

[Bryan Mayland]

Originally posted by Jay Bremner:
1) I remember seeing a thread on here showing the different version of Linksys WRT54G routers (for using in this application) and now, through all my searches, I cannot find it. I picked up a Version 6 yesterday with High-Gain antennas and am wondering if there is anything different I need to do or just follow the Wiki?

It it is a version 6, the Wikipedia page for WRT54G says that it only has 2MB of flash and 8MB of RAM. The standard LinkMeter image is 3.2MB so you'll have to build your own, stripping out as much as possible. I know someone has done it, but I don't know what the final config was. Also 8MB of RAM is pretty tight, considering we run out even with 16MB if you serve more than 2 HTTP connections at once. If you're going to squeeze it in, you've got your work cut out for you

Physically however, it should be similar, but the internal layout will probably be a little different so you may have to rearrange things a bit, either running wires to the HM board or mounting it above the serial port.

 

[Bryan Mayland]

Originally posted by D Peart:
Any idea why the router would not want to re-load the linkmeter-wrt54g-squashfs.bin file now?

The BIN file only works through the TFTP-while-booting interface. Once you're booted into OpenWrt, it only expects the generic TRX image. The BIN file is just the TRX image with a header on it that says basically "W54G (version) (version) (version)" that the boot loader (the one that runs the tftp) checks for compatibility before flashing.