Aries - Offline Air Quality Sensor

Cleaned up repo structure and now its a proper readme and documenting

Ok so i worked on the firmware today, technically loaded an example code on how to read data from the SCD 40, couldn’t find all the code and guides i could find on the TFT display kinda needed me to have one and for my use case with the sensor i need the actual physical everything. I do not want to use AI to write the code so i’m gonna wait till i have the components to code and test. so em yh, i think that’s it for design

Ok so today i worked on the CAD, i had to adjust my mounting hole on the PCB, so i switched Operating Systems (lets not ask question 😅), The casing is complete with lid and base with a place below for the LiPo since i am passing it under the Xaio. One major issue was getting my spline pattern (technically not a pattern), but eventually i got it.I really love how the deisgn came out 😎, up next will be the firmware for sensor reading, display and local access. Till next time Caio 

Started designing the case, from the base up, added the LiPo CAD, but then i realised the mounting holes had a diameter of 6mm, and i don’t have an M6 screw’s screw driver, so then back to KiCAD

Ok so i found the CAD model for the LiPo battery and did the full routing on Aries.
Placed the SCD40 sensor at the top Left, near but not too close to the OLED, didn’t want the microcontroller heat messing with sensor readings.
Used ground fill, routed everything, then added a Red Five from Star Wars silk screen image (i mean why not : ) ).
Added mounting holes so I can screw it onto the enclosure.

For assembly, I’m soldering headers onto the XIAO ESP32-C3, then soldering those onto the board. Same approach for the circular TFT display. The SCD40 air quality sensor is coming as a hybrid PCBA from JLC PCBA, along with the resistors.

I kinda mixed up my communication protocols on the schematic. I was feeding both SPI (for the display) and I2C (for the sensor) into the same pins. The sensor uses I2C with serial clock and serial data, and the display uses SPI with serial clock and serial data (but the data line is MOSI, master out slave in). I literally joined I2C signals with SPI signals, which obviously doesn’t work.
Caught it while routing and checked online to confirm, then i renamed the SPI clock line to SCLK and the MOSI line to match the display pinout, so em yh, i think that is it for now on aries, chao :)

Oh i totally forgot, i am adding a slit under the Xiao to pass my LiPo power lines to Bat + and - to solder.

So i started a mini project, that is turning out to be not so min. i am calling it Aries (yes cause the name sounds cool 🫠 )…Its supposed to be an offline room, air quality sensor that alerts you when the air quality is really bad, or when someone farts 😂.

Today i did the rough sketch, spent a lot of time to choose the sensors and components had to use Claude to cross check somethings like pin outs and power requirements for the project, and began wiring the schematics….🙂‍↕️i’ll be posting updates and possibly a voice over as i move on with this project… so em yh.

Currently this is the plan :
XIAO ESP32-C3,
SCD40 (CO2 sensor, I2C) =>SCD40-D-R2,
Circular TFT Display 1.28 Inch TFT LCD Display,
Switch for batteryLiPo 3.7V [ 503450 3.7V 1000mAh Polymer Lithium Rechargeable Battery with JST PH2.0 Plug ]
and then a Custom PCB with the circuitry for the sensor