LinkMeter v2 Homebrew BBQ Controller - Part 1


 
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Alright, I was thinking they were just for his SD card, but when I test that ground pin, I'm not getting 0V relative to the power jack. It's jumping around from 10-50mV. The button board pin 1 read 5.88V.
 
I've also tested just the Heatermeter running off the FTDI. I can see current /config and serial output. I see probe 3 at 256F and a NO PIT PROBE, whether or not a pit probe is connected. The button board works and scrolls thru menus.
 
Yeah the 2 little wires on my ttyS0 go to the SD card. Measuring on my router I've got 0.001V at that ground, 3.356V at the 3.3V pin, and 4.951V on my button board pin 1. If you've got 5.88V, that's way way out of spec (max is 5.1V) and something isn't right.

Also the probes should never read anything but off (U) if there's no probe connected, regardless of configuration. The voltage at each of the pins on the header relative to pin 1 (GND) should be 5V +/-2%. Relative to pin 21 on the ATmega (the pin to the right of the notch is 28, count down to 21), the probe pins should be 0V.
 
Odd, I rechecked it again this morning, and the button board 1 pin is reading 5.01, and the probe pins are reading 4.95-5.00 relative to ground, 0 relative to pin 21 of the ATmega.

Would having D1 backwards potentially damaged anything? It's the only thing I saw wrong with the board yesterday, and I removed it and replaced with a new diode. Pin 1 of the blower reads 12.03V, pin 2 reads 8.96.

I'm going to try test communication from the serial port on the router.
 
I followed the directions on page 13 and 47 to test the RX/TX pins via echo, but I don't see an echoed message. I do see a baud rate of 115200.
 
I ended up switching routers because the other one was able to pass the echo test.

The final thing keeping me from snapping the case together are the probes. They are very sensitive to how they are placed in the jacks, but even then they still drop in and out. I'm trying to figure out why, I checked the 5 pin connector relative to the ground and barrel of each probe jack and they check out. The pins on the Heatermeter are still checking 5V and 0V respectively.

When the probes are running, the temperature reported looks fine. They are ET-732's and with the configuration changed they both read room temperature on my desk.
 
For my ET-732's they were a little too long for the header jacks that Bryan picks for the ET-73 probes. You need to leave about a 1/8" gap in order for them to work properly.

To fix my probes, so that I could plug them "all the way in", I took a piece of plastic tubing that is used to hook up the ice maker for a refrigerator. I then cut off a small (1/8") piece, cut about a third of it out, leaving a C shaped piece of plastic. I then put that onto the probe and use a bit of heat shrink tubing and heat shrunk it to the probe with it pushed all the way onto the probe.

This basically created a small spacer on the probe so that when I plugged it all the way in, it would work without issue.

Hopefully that made sense
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If not I can cut another one and post some pictures.

dave

Originally posted by J Davis:
I ended up switching routers because the other one was able to pass the echo test.

The final thing keeping me from snapping the case together are the probes. They are very sensitive to how they are placed in the jacks, but even then they still drop in and out. I'm trying to figure out why, I checked the 5 pin connector relative to the ground and barrel of each probe jack and they check out. The pins on the Heatermeter are still checking 5V and 0V respectively.

When the probes are running, the temperature reported looks fine. They are ET-732's and with the configuration changed they both read room temperature on my desk.
Click to expand...
 
Ya I noticed they short the jack when you bottom them out. Good idea on making stops.

I've tested running with the board running off the FTDI cable and not the router, and I don't get probe drops.

Edit: I've tried my other power supply, and I don't get drops with it. It's the 9V/1A labeled supply I mentioned on pg 45, but tests at 12V. The supply I had been using is the Linksys branded 12V/1A that came with the router via Craigslist.
 
Originally posted by Bryan Mayland:
You can use any WRT54G that has 16MB or more of RAM and 4MB or more of flash, however the board probably won't fit right inside the case on account of there not being the huge space for it.

I'd looked at iteadstudio.com before I made my first board because they have some pretty dirt cheap prices. How long was the turnaround time from submitting your design to the board showing up?
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Boards came today but I wasn't home to sign for them. Hopefully I'll get to the PO tomorrow let you know how they look.
 
Everything can be controlled through the web interface.

Originally posted by Ben Fillmore:
Also, is the button board necessary or can everything be controlled through the web
interface?
Click to expand...
 
what all needs to be changed in the code to make it where the atmega328 chip works instead of using the atmega328p? I know there's a line in the 'MakeFile' anything else?
 
Originally posted by Ben Fillmore:
Also, is the button board necessary or can everything be controlled through the web interface?
Click to expand...
There's actually more that can be controlled from the web interface than on the unit itself with the buttons. It is convenient to be able to adjust the temperature and turn on/off lid mode, but not necessary. If you've got the parts it is really easy to drill a few holes into a piece of plastic / old CD to make one though.
 
Originally posted by Shane Woessner:
what all needs to be changed in the code to make it where the atmega328 chip works instead of using the atmega328p? I know there's a line in the 'MakeFile' anything else?
Click to expand...
The Makefile doesn't work yet, so you don't need to change anything there.

I know the only difference between the 328 and 328p is that the P is "PicoPower". I could never really find any documentation on what that means exactly though. I think it might just mean it supports the sleep states and the HeaterMeter code doesn't invoke any sleep states. It should just work straight up. You'll have to let us know but if you have any problems I'd be happy to help you work em out.
 
What are you using to program? I used the TINYusbISP to load my bootloader and the FTDI Basic Breakout 5V to load the program. I had trouble using Arduino IDE to load the bootloader from my gaming/workstation desktop, so I tried using my netbook (Windows XP). It worked with no hassle, so I also used it to load the program.

There have been a few occasions before where my netbook had an easier time accessing things, like updating firmware for various gadgets.
 
Tried the Arduino IDE with USBTiny and get nothing but errors, guess I'll try the FTDI basic then.
edit: bootloader went ok, it's the heatmeter software that is giving me all the errors.
 
OOPS...standby, my mouse seems to be all the problem, button not working properly....will update soon as I think I got it working!
 
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