Pax Instruments T400 thermocouple temperature datalogger

[zapta]

This badge may be a good fit for your product

http://arduino.cc/en/ArduinoAtHeart/HomePage

[charlespax]

This badge may be a good fit for your product

I looked into the Arduino at Heart program. For now the Arduino Open-Source Community is the best fit.

[zapta]

I looked into the Arduino at Heart program. For now the Arduino Open-Source Community is the best fit.

I was not aware of it, will take a look. Thanks.

[charlespax]

I looked into the Arduino at Heart program. For now the Arduino Open-Source Community is the best fit.

I was not aware of it, will take a look. Thanks.

Here are the programs:
Arduino AtHeart - The Arduino AtHeart program is designed for makers and companies wishing to make their products easily recognisable as based on the Arduino technology. The program is available for any product that includes a processor that is currently supported by the Arduino Development environment (see list below).

Arduino Certified - The Arduino Certified program is designed for companies using processors not currently supported by Arduino who want to certify a basic level of compatibility with the Arduino platform..

Arduino Community Logo - We want to foster the spirit of our mission giving communities and individuals the opportunity to continue organizing locally or globally, online or offline around Arduino, being recognizable as part of this amazing spontaneous community.
You can use the Arduino Community Logo to identify your local group, as it is or adding the name of your group.

"For more information about the "Arduino Certified" program please write to: certified [at] arduino.cc"

I requested certified [at] arduino.cc to review the Pax Instruments website. They asked me to add the trademark symbol and said it was good to go as you see on the page right now.

[charlespax]

Pax Instruments is going to MakerFaire NYC to show off the T400. Come visit exhibit #42316 “Pax Instruments T400 Temperature Datalogger” and play with working prototype hardware. Who's going to MakerFaire?

[zapta]

Sweet! Matt Mets made the Blinky Tape. He's also hacking on the firmware for the T400.

It arrived today, will try to control it from a Python script.

BTW, I was surprised how short it is. Expected more for that price.

[charlespax]

The T400 Kickstarter campaign is live!

It’s official! I’ve launched my first product for Pax Instruments on Kickstarter. You may have seen my post on Facebook or Twitter, but if you haven’t already, meet the T400 Temperature Datalogger.
 
The T400 can connect to four thermocouples simultaneously, and logs temperatures directly to an SD card, so it can operate independently or while connected to a computer.

I want to continue developing this product and expand the line to other instruments and I’d love your helping making it happen!

Here’s how you can help:

First, share the Kickstarter campaign on social media like Facebook and Twitter. Also contact any friends you think would be interested in the T400.

Second, if you can submit my project to the tip lines at sites you read, it’ll help my cause a lot. Tell them there’s a Kickstarter project you like trying to make Open Source lab instruments, so people with projects in mind don’t have to spend an arm and a leg.

Third, With a Kickstarter campaign, a lot of the success seems to come from attention at the very beginning. So it would be amazing if you could back this, at least for $1, and then share the campaign to your networks.

Thanks so much for helping me make this a reality.
 
Kickstarter campaign: https://www.kickstarter.com/projects/1880050573/pax-instruments-t400-temperature-datalogger

- Charles

[urlkrueger]

Do you have provision for aging of the thermocouples?

I use type K tc's at 1200C and they definitely loose umph with age at these temperatures.  A method to provide a user adjustable offset for each tc would be a requirement in my book.

[charlespax]

I use type K tc's at 1200C and they definitely loose umph with age at these temperatures.  A method to provide a user adjustable offset for each tc would be a requirement in my book.

That's a good idea. User configuration per thermocouple would be great. I've included your idea in the Calibration routine issue on Github.

What is involved in that calibration?

[charlespax]

I just posted an update http://paxinstruments.com/t400-may-production-update/

Since our March update the T400 has moved steadily forward. The most challenging aspects of the T400 project appear to be behind us and the T400 schedule is now almost exclusively dictated by factory lead times. If everything goes smoothly, you should have your T400 some time in August, probably earlier.

Thermocouple connector

Creating the custom thermocouple connector has been the single biggest issue we have faced. We did a tremendous amount of testing on the handful of seemly suitable connectors out there only to find nothing would meet our needs. In the end we spent a lot of time and a lot of money making what is the world's first fully open source connector.

We believe this will be useful to other hackers, so you will be able to purchase the Pax Instruments surface mount thermocouple contacts in our store as soon as they become available. The precision metal stamping factory has our money and our designs. We should have samples for approval before June 15th.

Enclosure
The design is complete. SLA and CNC machined prototypes are approved. We are just waiting on the connectors, so we can confirm everything lines up before cutting a mold. The top panel that interfaces with the thermocouple connectors is dependent on the custom thermocouple connector and cannot be approved until we approve the connector. We talked to the factory about cutting all the part cavities except the top panel and cutting the top later. They said it would be more expensive and only save us a few days.

Silicone keypad

Because the enclosure design is so complete we decided to start production on the silicone keypads. You can take a look at the button specifications to get a sense of how they will look. We are shooting for black icons on a white smudge-resistant background.

Electronics
The schematic design is complete and the latest version of the board works as expected. We are making one more revision to swap out the prototype Keystone connector with our custom connector. This is a trivial change of the connector footprint.

To ensure the PCBAs and enclosure match properly the factory will fully assemble the T400s with enclosures. This will allow us to fix any unforeseen PCB mistakes should they arise. We will begin PCBA production as soon as we have the injection molded enclosures.

Firmware
The firmware is expected to be complete in time for MakerFaire Shenzhen June 19th. You can track the current milestone on Gihub.

New Products

We took a few days while waiting for prototypes to refine some of the tools we made while developing the T400 and released a few new products.

If you are interested in our LCD, but were not sure how to interface with it, we now offer the Pax Instruments Graphic LCD 132×64 Arduino Shield. The LCD shield incorporates the same pin swapping technology as the Arduino Configuration Shield.

We also stock a high quality, low cost K-Type thermocouple with winding handle. The connector is from Omega and sports a standard PTFE-coated K-type thermocouple.

We came across a few hundred ATmega1280-16AU chips for next to nothing and put them in the store. We're thinking about making a small run of some fun project for them. If you have an idea you'd like to share, please join us in the forum.

If you'd like to stay even more up-to-date and hear more from Pax Instruments, please like, follow, and share us on Facebook, Twitter, and our blog. Thank you for your continued support :-)

[charlespax]

We made it into the Adafruit store! This is a huge step. Thanks to all who supported us so far :-)

https://www.adafruit.com/products/3081

[PointyOintment]

We made it into the Adafruit store! This is a huge step. Thanks to all who supported us so far :-)

https://www.adafruit.com/products/3081

Great news! I haven't been following the T400 closely—I didn't even know it had reached production—but I was just thinking the other day that I should buy one.

[charlespax]

Great news! I haven't been following the T400 closely—I didn't even know it had reached production—but I was just thinking the other day that I should buy one.

Thank you for checking out the project     I shipped in back in February. So far the feedback has been positive. The only complaint has been that the MicroSD card can be difficult to remove with short fingernails. Totally my fault. Whoops!

The Adafruit store is out of stock, but should be back up soon. You can always get the T400 in my store. Or you could head to the github repo and make your own 

How do you plan on using your T400?

[Kean]

Thanks for the reminder Charles, I've finally ordered one.

Also really glad to see you selling the custom enclosures and buttons by themselves.  I've ordered some to try out a design for some custom handheld instruments (light, fluorescense & spectrometry related and/or small current sources/loads for the bench).

[charlespax]

Well, that's exactly why I'm making them available :-)   I'd be happy to help if I can. Just let me know.

[charlespax]

The T400 was featured on the Mailbag and got a thumbs up! 

[charlespax]

If you're interested in influencing what might be the next device, please join the conversation at https://www.eevblog.com/forum/projects/pax-instruments-multilogger/

[charlespax]

In the latest firmware in github gives 770 bytes available without removing any functionality via flags. If flags are used, a total of 9,570 bytes are available.

http://community.paxinstruments.com/t/customising-the-firmware-to-do-other-things/138/8

[jpanhalt]

I realize this thread is old.  Charles Pax has kindly helped me out with finding a project box for my "Smart Roast" and asked that I post some pictures of how I repurposed the T400 box.  (See related thread here: edit:deleted link because of Chrome warning)  This project is/will be open source.  Code is MPASM.  I just have not had time yet to get that documentation cleaned up, but I will add it here.

My project used a PIC16F1789 and MAX31856 TC amplifier.  The rest is pretty standard support stuff.  I went with an Omega TC socket, and it was just a tiny bit too high to fit under the LCD that snaps into the board.  That was solved by making a slot in the board and effectively mounting it upside down on the bottom surface.  See attachment. 

The thing is, of course, a roast thermometer.  I added a clock for total time, a calculation of rate for internal temperature, and a calculation of finish time based on user input of desired final temperature.  With beef roast or pork and an oven temperature well above the target temperature (e.g., 325°F vs. 125°F/160°F) that rise in temperature was fairly linear shortly after internal temperature starts to rise.  I had noticed that linearity for years and used to do the calculation by hand.  I could never convince my children to keep such records, so I made this project for them.  I now like it too.

The case back panel is currently left open for access to the programming pins.  Once that is "done," it will be closed.  The other attachments are for the TC (type K) and battery charging/power (USB).  For the first prototype, I decided not to include on-board charging and have left the battery unattached.  Nevertheless, I have included a picture of the T400 battery compartment, which I really liked.

PCB back shows detail of how the TC socket is attached.
PCB w.LCD shows detail of how the LCD mounts to the PCB.
MAX31856  shows the top attachment of the TC socket.  I used cyanoacrylate adhesive to fixture the socket to the PCB strap on the backside.  It seems quite rugged.
PCB top is the whole board with the LCD flipped forward.
The final photos is just the PIC1789 for those who like to see the MCU.

I extend my sincere public thanks to Charles Pax.  Without the T400 case, getting this gadget to look so neat may not have happened.

Regards, John

[jpanhalt]

Penultimate SmartRoast Prototype (maybe)

I have mentioned my "SmartRoast" project in other threads.  At the suggestion of Charles Pax (see my previous post), I decided to post more detail here.  It's a roast thermometer that calculates a finish time from the user entered target temperature.  It does not predict temperature rise after removal from the oven.  The basic project was working within one Winter.  I then spent the next 4 years working on the graphical display, PCB, and perseverating about when to do my very first reflow soldering (done 2022).  Other projects were also done during that time.  My original PCB design included a BMS for a LiPo battery; however, that was deleted at the last minute as I became worried about heat and keeping the project simple for my first reflow attempt.  It runs on a 5V wall wart with a miniature USB plug. 

Changes anticipated or being considered for the next version: 1) On board BMS with a USB-C connector (definite); 2) Selection of meat type; 3) An initial calculation based on size and weight of the roast;  4) Change the MCU chip; 5) Change the TC amplifier and/or better noise filtering; and 6) Possible but less likely a change in the display.

Attached are the schematic and board design submitted to OshPark, Assembly code, some flowcharts that may help a reader find their way through the spaghetti "logic," and a link to the LCD that was used.

Comments:
1)  Coding is in Microchip Assembly and MPLab 8.92 tool suite.  It may not appear in text or assemble properly with the current assembler in MPLAB X IDE.
2)  RE: TC amplifier (MAX 31856).  That chip is sensitive to noise on the TC leads and can freeze up.  If that happens, turn device off, wait a few minutes, and restart.  I found that wrapping the TC leads through a ferrite filter/toroid helps.  The toroid is shown in some of the pictures.
3)  Flowcharts were done originally in draw.io which is now diagrams.net .  I continue to use the draw.io version.  The Histogram flowchart has not been updated in quite awhile and should be considered a rough draft.
4)  The LCD is not shown in the BOM.  It was obtained via AliExpress from Laurellcd.  It is described as: 13264 COG ST7567 lcd display graphic module SPI Serial 12pin FSTN gray with bright backlight serial module LG132643-FDW .  Note the FFC comes/came in 2 pitches.  The prototype has the narrower pitch.  The plastic legs snap into oval slots on the PCB
Link: edit link to avoid Chrome warning
User's Manual:
GUI
The switches are numbered top to bottom and left to right.  Upper left is SW1; lowest left is SW3.
During POR
SW1 = Run
SW2 = Menu select
SW3 = Power on/off
SW4 = Increase in Done temp
SW5 = Decrease in Done temp
SW6 = Inactive (not implemented)

During Run
SW1 = Clears screen and timer (settings unchanged from POR)
SW2 = Backlight on/off toggle
SW3 = Power on/off
SW4 = Command scroll up
SW5 = Command scroll down
SW6 = Inactive (not implemented)

Regards, John

[Kean]

I extend my sincere public thanks to Charles Pax.  Without the T400 case, getting this gadget to look so neat may not have happened.

Nice.

I bought a number of the T400 cases from Charles to build my own projects into as well.  Nothing I ever finished, but I still do use my Pax T400 datalogger.