My Barbduino Project

[Chris__M]

Earlier, I posted about my plans to build a digital controller for my Traeger pellet grill using the Arduino open source microcontroller board.

I’m new to the Arduino (although not to programming), so my first step was to buy a simple Arduino experimenter’s kit and do some general non-BBQ projects, to familiarise myself with the kit and its capabilities. This is still ongoing. I made a point only to buy the Arduino kit, and not the add-ons I might later require, such as the WiFi and LCD Screen options – doing so means I will learn to walk before I run, and limits my spend, in case the project doesn’t fly.

However, in my head I already had a grand plan for what it would do – controlling all aspects of the grill, connecting to my home network by WiFi, running a simple web-server displaying the temperatures. It is easy to let your imagination get carried away.

I have now thrown away those ideas, and replaced them with a simpler plan that will be a lot easier to achieve, while still allowing me to develop it further at a later date.

The manual controller currently controls three things: the igniter rod, which heats up for the first 4 minutes the grill is switched on, and ignites the pellets; the auger, which feeds the grill with pellets for fuel; and the fan, which is wired into the main controller on/off switch and provides air for combustion.

For the moment, the existing manual controller is going to remain in place, with the Arduino connected in parallel in the auger motor circuit. The manual controller will continue to control the igniter rod.

The connection from the manual controller to the auger motor is going to be interupted by a relay connected to the Arduino, which will be normally closed. This means that when the Arduino is unpowered, the manual controller is controlling the auger motor. When the Arduino is in use (and controlling the auger motor via a second relay), the manual controller is taken out of the auger circuit.

The WiFi element is now removed, and replaced by my netbook, connected to the Arduino by USB, and receiving a simple feed of temperature data. The netbook is also what will power the Arduino.

The advantage of all of this is that my regular cooking need not be hindered by my experiments; and even when the project is finished, in the event of any problem – hardware or software – I can revert to the manual controller simply by unplugging my netbook, and removing power from the Arduino.

The removal of the need for WiFi or onboard LCD display makes things a lot simpler, and means I can concentrate on the actual control loop. It also means I can develop my ideas for no additional cost that the kit I have already purchased, plus a couple of relays.

For remote control, I can run VNC on my netbook, and connect from my desktop or phone, and monitor temperatures.

I’ve seldom used my netbook since getting my Android phone, so it will be good to find a use for it.

As you can see, my project has also received a name – the Barbduino. Cheesy, perhaps, but I like it.

[JEC]

Sounds like a great project if only I had the time to do something similar. Look forward to updates

[Chris__M]

I don't know anything about this stuff but I would love to send you some stuff to put together for me. I have probes, controllers and some hard ware that I can't manage to pull up enough bravery to try and put power to.

I have to admit, I'm no expert, but I do like to tinker, and I am a fairly decent Google researcher.

Tell me what you have (either here or in pm), and I'll have a think. Although if there is any complexity to it, I may want to get this project working before looking at other kit, I'm perfectly happy to put my mind to it.

[Chris__M]

Sounds fine to me.

As it happens, I have some good friends in Wroughton that I really should visit some time this summer, so if it turns out to be something I think I can help with, I'll throw some dates at both you and them, and see if we can find a window of opportunity somewhere!

[Chris__M]

Am still nowhere near connecting up to my grill, but have achieved the following, as individual tasks.

• Having the arduino control a relay.
• Connect up multiple temperature probes from my Maverick to the arduino, and have it calculate the temperature.
• Bi-directional communications between my netbook and the arduino. i.e. I can talk to the arduino from my netbook, and it can talk back, over the USB connection. This will allow me to log the pit and food temps on my netbook, and turn the "temperature to maintain" up and down. Ultimately, this will be done over WiFi, using a web browser, but for now I am doing serial comms using a Micky Moose perl script.
• Fake remote control by installing VNC on my netbook. This will allow the netbook to be connected to the arduino, connected to the grill, downstairs, but have remote control of the netbook (and therefore the arduino) from my desktop upstairs.

Having got that far, it is just a case of pulling it all in together, and the the arduino can be set loose on controlling my pellet grill. However, that is when the real fun begins, with writing the control programme.

I'm going to be otherwise busy for the next couple of weeks, but I also need to order some components. Both the relay and the resistors are cheap components that came with my arduino kit. In particular, the resistors I have are +/- 5%, which is sufficient for testing, but not for proper use.

[Peter Webb]

You might like to be aware that ETI Ltd (UK) the makers of the Thermapen pocket thermometer, are launching late this summer a new BlueTherm which is a Bluetooth thermocouple thermometer, which will transmit your cooking temperatures directly to your phone or PC.

ETI Ltd are working on the Android App right now, with an iPhone App to follow this autumn.

The thermometer has a very wide temperature range up to 300°C (572°F) and is accurate to 0.5°C (0.7°F). Watch their ETI website for more information http://www.etiltd.co.uk

[British BBQ Society]

looking forward to having a play with one!
Toby

[Chris__M]

You might like to be aware that ETI Ltd (UK) the makers of the Thermapen pocket thermometer, are launching late this summer a new BlueTherm which is a Bluetooth thermocouple thermometer, which will transmit your cooking temperatures directly to your phone or PC.

ETI Ltd are working on the Android App right now, with an iPhone App to follow this autumn.

The thermometer has a very wide temperature range up to 300°C (572°F) and is accurate to 0.5°C (0.7°F). Watch their ETI website for more information http://www.etiltd.co.uk

I am sure it will be of interest to many, although its application to the project I am discussing here is unlikely.

To the best of my knowledge, most bluetooth devices have a range of about 10m. Which means it wiil be great for someone to display temps on their Android phone, while standing next to the grill, but not that useful for remotely monitoring the grill at the slightly greater distances I am dealing with (no to mention a couple of brick walls).

Also, the remote monitoring is only one aspect of my project, which is primarily aiming to automatically control the grill.

Having said that, I would encourage you to publish an API for the device, as well as the Android and Iphone apps you have planned, which would allow peope to incorporate your BlueTherm into their own projects.

[Chris__M]

I haven't done that much on my Barbduino BBQ Controller project for about a month. No good reason, other than simply doing other stuff. During that period, I have bought some stuff, like the necessary sockets for the probes, and other components.

After hesitating over how the device is going to connect to the outside world, I decided to abandon the idea of the WiFi shield (daughter-board), and bought a standard Ethernet shield instead, allowing wired connection. The reasons for this were various.

• The Ethernet shield, at 35 quid, is half the price of the WiFi shield.
• It appears to be a more "standard" device than the WiFi shield. There seems to be a common Ethernet library, whereas the different makes of WiFi shield all seemed to require their own code. (I may be wrong on this, but it did seem that way, from what I have read.)
• The Ethernet shield comes with a mini-SD card slot built in - useful for data logging.

Should I (or someone wanting to use my code) really needs WiFi, they can simply use an Ethernet to WiFi bridge device; furthermore, I suspect the price of the Ethernet shield plus such an adapter would still be about the same as the WiFi shield. As it happens, I no longer need WiFi to connect up, as my garage once more has a network connection, which I can tap.

So last night I was playing with the Ethernet Shield, and got as far as a simple plain text web page, which displayed multiple probe temperatures on screen, and refreshed every X seconds. This was achieved by running simple web server code on the Arduino. It was surprisingly easy to set up, and I was delighted to see it working - I was able to view changing temperatures on my desktop and my Android phone. As such, I have already bettered the capability of my ET-73, in that I can access the temperature information anywhere in my house, including my upstairs office.

The Arduino board has 6 analogue pins, which means I could monitor up to 6 probes. For now, I am going to allow for just 4 probes, which is the most I expect to need - 1 pit probe and up to 3 food probes.

[joker smoker]

I wish I could even begin to understand this technology...