Editor’s note: Noel is the last man standing from the AppsLab to work at Oracle. He created this project while being part of the Oracle Groundbreakers Team. The rest of the original AppsLab team members are now scattered throughout different companies in the tech sector.
For years I’ve been wanting to create something fun with the almighty esp8266 WiFi chip. I started experimenting with the esp8266 almost exactly four years ago. Back then there was no Arduino, Lua or even MicroPython ports for the chip, only the C Espressif SDK. Today it is fairly easy to write firmware for the ESP given how many documented projects are out there.
Two years ago I was very close to actually producing something with the esp8266. We, the AppsLab team, partnered with the Oracle Technology Network team (now known as Oracle Groundbreakers Team) to offer an IoT workshop at Oracle Open World 2016. I reached out to friend-of-the lab Guido Burger from fab-lab.eu and he came up with a clever design for an IoT badge. This badge was the swiss army knife of IoT dev badge/kits. Unfortunately, we ran out of time to actually mass produce this badge and we had to shelve the idea.
Instead, we decided that year to use an off-the-shelf NodeMcu to introduce attendees to hardware that can talk to the Cloud. For the next year, we updated the IoT workshop curriculum to use the Wio Node board from Seeedstudio.
Fast forward to 2018. I’ve been following emerging use cases of e-ink screens, and I started experimenting with them. Then the opportunity came. We needed something to highlight how easy it is to deploy serverless functions with Fn project. Having a physical device that could retrieve content from the cloud and display it was the perfect answer for me.
I reached out to Squarofumi, the creators of Badgy, and we worked together to come up with the right specs for what we ended up calling the Code Card. The Code Card is an IoT badge powered by the esp8266, a rechargeable coin battery, and an e-ink display.
I suggested using the same technique I used to create my smart esp8266 button. When either button A or B are pressed it sets the esp8266 enable pin to high, then the first thing the software does is keep the pin high until we are done doing an HTTP request and updating the e-ink screen. When we are done, we set the enable pin to low and the chip turns off (not standby). This allows the battery to last much longer.
To make it even easier for busy attendees to get started, I created a web app that was included in the official event app. The Code Card Designer lets you choose from different templates and assign them to a button press (short and long press).
You can also choose an icon from some pre-loaded icons on the firmware. Sadly at the last minute, I had to remove one of the coolest features: the ability to upload your own picture. The feature was just not very reliable and often failed. With more time the feature can be re-introduced.
After attendees used the Code Card designer they were ready for more complex stuff. All they needed to do was connect the Card to their laptops and connect via serial communication. I created a custom Electron Terminal to make it easier to access a custom CLI to change the button endpoints and SSID information.
— Oracle Groundbreakers (@groundbreakers) October 24, 2018
Lastly, if you paid attention you can see that we added two Grove headers to connect analog or digital sensors. More fun!