Another week has passed for the challengers of the Pi Chef Design Challenge, bringing us up to week ten!  We’ve had some excellent updates in the past seven days and I would like to highlight a few of them, but before I get started let's take a moment to learn more about this challenge.


Pi Chef Design Challenge


About The Challenge


Featured as the first design challenge of 2018, the Pi Chef Design Challenge opened for project idea submissions in October of 2017, which was met with many submissions from community members. As I mentioned earlier, the challenge is based around the Raspberry Pi 3 Model BRaspberry Pi 3 Model B SBC. Challengers have eleven weeks to develop their project, and share their progress in a series of weekly update post. By posting a minimum of ten update post, challengers become eligible to win several awesome prizes, and the chance to become one of our prestigious design challenge winners.



Entering the challenge is not limited to just the ten chosen community members though,  anyone can join the Challenge as a non-sponsored Challenger. Here's how: Simply get buy  a Raspberry Pi 3 model B and integrate it into your project, as well as post 10 blogs chronicling your project’s progress into  the Pi Chef Design Challenge space (tagging your blogs 'IoT on Wheels'). All Challengers must build their projects in accordance with the Challenge's terms and conditions, and all projects must include the Raspberry Pi 3 Model B.



The Official Kit, and The Prizes


On January 10, 2018 Element14 announced the 15 community members that were picked to participate in this challenge, and those challengers received a kit of sponsored components to use in their design which was based around the Raspberry Pi 3. If you would like to purchase the official kit, click here.


Each kit contains the following items:


To learn more about each of these components or to purchase them to use in your own project, visit the official kit announcement at the links above.


Each challenger is competing to win one of three prize packs that feature the following prizes:


Grand Prize

        • Breville Barista Express Espresso Machine
        • $1500 USD Newark element14 / Premier Farnell Cart

Runner Up

        • Whynter Ice-Cream Maker
        • $750 USD Newark element14 / Premier Farnell Cart

Third Place

        • Breville Tea Maker
        • $500 USD Newark element14 / Premier Farnell Cart


A finisher who has completed their project, used the Raspberry Pi, posted 10+ updates in the Pi Chef space and adhered to the requirements in the Terms and Conditions will receive a mystery package of element14/Premier Farnell products valued at $65 USD.



The Past Week In Review


Over the past 7 days, March 18th - March 24th, we have had a total of fifteen updates posted across ten projects. I’m going to pick a few of my favorite updates from the week and highlight them below, but before we get into that lets take a look at which projects were updated this week!




This Week’s Top Updates



Project: Smart Range Hood - Pi Chef Blog #11 - Any Pi Chefs out there cook their Pi yet?



We all have had that heart sinking moment when we fire up our complete project for the first time and things obviously are not working as planned. James O'Gorman (aspork42) experienced that very thing recently when he powered up the Raspberry Pi inside his Smart Range Hood for the first time. “We only have one week left and I want to get things moving. I finalized most the remaining loose ends and went about the final installation. Once mounted, I plugged in the Pi - and bad things started happening! I hadn’t hooked up any mains voltage yet, but my pcb started to flicker on and off. The LEDs were flashing; the buzzer was going crazy,” he wrote. “I checked for sorts between power and ground but didn’t have any. I looked around some more and finally found that the 40-pin header for the screen was plugged in 1 pin over - aaaaaarrrrggggghhhh!!!! How much magic smoke got out???” 


After deciding to wait until the next day for his head to clear, James tried his SD card in another Raspberry Pi, and noticed that the I2C devices were not appearing when polled. This led to James checking the config file, revealing that I2C and SPI were somehow disabled during the failed power-up event. After enabling both of the protocols everything but the screen seemed to work as intended. Unfortunately after more troubleshooting, James determined that the screen was dead and would need replacement. Head over to the link above for the full rundown, and to find out what James plans on doing now that the screen is no longer functional.



Project: Bake Mate  - Pi Chef Blog #13 - Mobile notifications using IFTTT



Our second featured update this week comes from project Bake Mate by Avner Fernandes (avnrdf). After realizing that his initial plan to utilize the oven built in thermostat as a means to acquire the oven’s internal temperature was flawed due to inaccuracies within the thermostat itself, he decided to use IFTTT and a timer to send notifications when the baking process is finished. “I had proposed a system that lets Bake Mate generate an alert when the bake timer runs down to zero, but after Bake Mate - Pi Chef Blog #6 - Measuring Oven Temperature , I realised that the thermostat in my oven isn't very accurate. Hence, Bake Mate will send periodic 'timer' notifications which reminds the user how much time remains, and 'temperature' notifications when the temperature in the oven fluctuates too far from the temperature required by the recipe,” he wrote.


Using his Bake Mate Python application, Avner is able to  send the recipe name, internal oven temperature, and required temperature to IFTTT which will then send push notifications back to his smartphone. While this method works, it does have a few flaws such as requiring an internet connection, and the IFTTT service limits the number of API calls you can make in a set amount of time. This means that if Avner allows Bake Mate to send data up to IFTTT too many times in a given period of time, the service will reject his request. “A local MQTT service is an alternative, or even using the NFC board and Tasker: BakeMate sends the bake time to the phone, and Tasker sets an alarm,” he wrote.



Project: Automatic Dough Shaper - Pi Chef Blog #9 - Mechanical Construction Part 2 and Design Changes



Making my list for the second week in a row is project Automatic Dough Shaper by AnnaLisa Davis (a_davis_22). In the project’s ninth update, she continues forward with the shaper’s mechanical assembly. While there is not much electrical work in this update, I still wanted to feature it because it’s rare that we see such in depth mechanical assembly builds during design challenges. Unfortunately Annalisa has had to cut back on some features and functionality of the design in order to make next week’s cut off date for projects to be finished. “I've been trying to figure out how to incorporate this functionality into the PyCNC code as it is, and I've finally come up with a solution. I don't have an extruder, but since the extruder command is just the same as any of the other axes (step and direction outputs to a driver board), I can use that for the roller control. Next, in order to control the arm that moves the pan into the oven, I need at least 3 GPIO pins. PyCNC has 4 pins set aside for servo motor use (which comes from the reprap option to use servo motor control),” she wrote. “I'm pretty sure that these pins actually aren't used, which gives me just enough to control the arm and 1 pin left over to heat up the oven. This is where I start cutting corners. Instead of using a thermistor to measure the temperature, I'll just figure out how long it takes to heat the oven to 350 F and have it turn on that long. It will work well enough to bake cookies.”



That is going to wrap up this weekly summary of the Pi Chef Design Challenge. Remember to check back each and every week for the duration of this challenge for a summary post from the previous week’s updates. If you would like to learn more about this challenge, and to see what progress has already been made, head over to the its official challenge page, and if you would like to follow what I am up to these days, follow me on Instagram. I apologize for the summary being a little short this week, but I am currently traveling to Atlanta to attend a woodworking event and to hang out with almost one hundred of my fellow maker content creators. I will see you next week, and as always, remember to hack the world and make awesome!



Weekly Summaries About This Challenge

  1. Design Challenge Weekly Summary: Intro to the Pi Chef Design Challenge
  2. Design Challenge Weekly Summary: January 14 - January 20, 2018
  3. Design Challenge Weekly Summary: January 21 - January 27, 2018
  4. Design Challenge Weekly Summary: January 28 - February 3, 2018
  5. Design Challenge Weekly Summary: February 4th - February 10th, 2018
  6. Design Challenge Weekly Summary: February 11th - February 17th, 2018
  7. Design Challenge Weekly Summary: February 18th - February 24th, 2018
  8. Design Challenge Weekly Summary: February 25th - March 3rd, 2018
  9. Design Challenge Weekly Summary: March 4th - March 10th, 2018
  10. Design Challenge Weekly Summary: March 11th - March 17th, 2018
  11. Design Challenge Weekly Summary: March 18th - March 24th, 2018
  12. Design Challenge Weekly Summary: March 25th - April 1st, 2018