Rainfrog Inc.

Tag: Data Logging

  • Introducing the ThermoTooth 3000!

    Introducing the ThermoTooth 3000!

    Here it is – what I’ve affectionately dubbed the ThermoTooth 3000 – a fully wireless, dual channel, K style thermocouple prototype. She had her first successful Bluetooth session with my Mac tonight, and even with her limited code, she’s quite a smart gal! Over a simple wireless serial connection via terminal, I am able to select which thermocouple to monitor, and trigger individual Celsius or Fahrenheit readings, or both. No special drivers – just a Bluetooth serial connection.

    For the geeks like me, she’s built on an Arduino Uno prototyping controller board. Stacked on top of that is an XBee shield, providing the networking connectivity beyond the basic USB already present on the UNO. The XBee shield currently houses a Seeed Studio Bluetooth Bee, which provides the Bluetooth connection layer. The two K-style thermocouples connect to the Uno via two Max6675 chips, each providing cold-junction compensation and digital conversion of the thermocouple voltages for its independent channel. The sheer amount of electronics here is definitely overkill – I’m sure the cumulative brains of this could drive a car, but that’s how prototyping works.

    First off – it’s not meant for live production. I built it in the hopes I could pair it with an iOS device, and negotiate a wireless serial connection via Bluetooth. I know the device functions well, but the external connectivity of iOS itself still holds unknowns for me. The XBee shield offers the advantage of being able to swap a regular wireless network interface for the Bluetooth module in case the Bluetooth method is unsuccessful.

    Hopefully, a more permanent solution is on the way. I’ve been contacted by a manufacturer who is currently developing a Bluetooth thermocouple they plan to bring to market this fall. Naturally, this is great news for a lot of us looking for automated readings. They have not discussed the expected price, but the product itself sounds great! The manufacturer has agreed to sending me a prototype for evaluation once the release date gets closer, but in the mean time – I needed something to develop with now.

    This is why I built the TT3000. The majority of the code involved to implement thermocouple support will likely be designing the Roastmaster interfaces and its internal data structures, and setting up the communications framework to be used between roasting curves and wireless devices in general. The Bluetooth serial protocol has seemed quite easy to work with while prototyping the TT3000, so I’m hoping that this venture will be successful, and that adding support for the new product (as well as any others that may crop up), will be fairly easy to add ONCE I get support for wireless thermocouples in general built into Roastmaster.

    I’ll post back here with updates as development progresses. This isn’t at the absolute top of my development list – there are several feature requests/tweaks I want to finish up first, but I plan to be working on this until I find a workable solution.

    As always – if you have any input – please let me know.

    Cheers, Danny

  • Calling All Thermocouples

    Calling All Thermocouples

    OK, so I’ll admit it… I love the nostalgia of analog devices.  As a kid I assembled a rolling ball clock – the kind that resembles an intricate, miniature roller coaster, where time is measured by the number of balls on each “track”. I loved it! Unfortunately, it woke the whole house up at midnight, so I, alone, was unanimous in that, but to me it was the most wonderful invention I had ever seen.

    The programming side of my brain, though, makes me a fair-weather friend to analog devices. For all their nostalgia, sometimes digital is just plain easier… and better. Such is the case for me with my roasting thermometer. There’s absolutely nothing charming about craning my neck upside down to read the accurate bean temp at regular intervals throughout a roast. And, though Roastmaster makes it easy to input temps with the keyboard, an automated solution would be much better.

    For some time now, I’ve been wanting to make the jump to something digital. I’ve held off, hoping I could find a device that I could integrate with Roastmaster to accommodate the automated readings. There are endless USB data loggers out there, but without a USB port on any iOS device, they may as well be turkey probes. I did find a high-end Bluetooth thermocouple as well, but any price that is listed as “Call for quote” is usually just too ridiculous to display. I did, by the way… and it was.

    I was hopeful when the iGrill bluetooth thermometer was introduced. It’s basic, but it’s an all-in-one package that looks great, and would do the trick, as long as the makers would release the SDK for other apps. Or, so I thought – turns out it’s not capable of reading temps high enough for coffee roasting. I’d like to talk to the manufacturer and see if this is hardcoded in the electronics, or simply a limitation of the probe supplied with the unit. For the moment, though, mine is sitting quietly and sadly, unused.

    I’m aware that there are build-it-yourself open source Arduino solutions out there. I’ve researched one, and it is feasible from what I can read. I had hoped for a prepackaged solution, since we’re coffee roasters, not electronic engineers. But, being in this community for quite some time has taught me that often they do overlap. I’m thinking I may just take the plunge. Being open source – I anticipate it will work well, but probably won’t win any beauty contests. Still, though, it will give me a tool to at least construct the framework Roastmaster will need to work with these devices, and as new solutions come to market, those will be as easy to add as creating a device description for them, or so I’m hoping.

    In the mean time, if anyone knows of a Bluetooth, LAN or, dare I ask for it – an iPhone dock-style thermocouple – available for a reasonable price, with a public SDK, please let me know.

    Cheers and Happy Roasting,
    Danny