cdfer/kea-co2

Firmware for a ESP32 Based true CO2 Monitor

Kea CO2 ✨

Kea CO2 is an ESP32-based device designed to visualize CO2 levels. It offers real-time graphing capabilities through a web interface, an external backup clock, fail-safe data storage, timezone support, and time synchronization via an unlocked Wi-Fi network server (STA + AP mode). The PCB also supports JTAG debugging through a breakout connector.

Known Limitations with Current Version

• Fixed 1-minute data recording interval.
• Fixed 2 MB maximum size data file (~60 days at 1-minute interval).

Getting Started

If you encounter any issues while testing this code on a device, please consider adding them to this repository.

Prerequisites

The following libraries are used in Kea CO2:

• espressif32 Arduino Framework
• AsyncTCP-esphome (LGPL (c) Hristo Gochkov @me-no-dev and others)
• ESPAsyncWebServer-esphome (LGPL (c) Hristo Gochkov @me-no-dev and others)
• NeoPixelBus (LGPL-3.0 license (c) Michael C. Miller and others)
• ArduinoJson (The MIT License (c) Benoit blanchon)
• Apex Charts (JavaScript) (The MIT License)

Installation

1. Clone the repository.
2. Install the required libraries (PlatformIO does this automatically).
3. Compile and upload the code to the ESP32 device.

Usage

The Kea CO2 device illuminates a strip of WS2812B addressable RGB LEDs to display the ambient CO2 level scale. The CO2 data is obtained from a Sensirion SCD4X sensor, and the LEDs are adjusted based on the ambient light conditions.

The device is capable of downloading a spreadsheet containing CO2, temperature, and humidity data. The data is stored in a fixed 2 MB file, which can hold up to 60 days of data at a fixed 1-minute recording interval.

To Sync the Time through Wifi just setup a hotspot with the name time and password 12345678 On Power the device will connect to the network and sync the time (Green Pulse if successful).

Useful Extensions

• Better C++ Syntax
• Code Spell Checker
• Live Server
• PlatformIO IDE
• PuTTY for Standalone Serial Logger

Wiring

Name	Designator	Footprint	Quantity	Manufacturer Part
CR1220	BT1	CR1220	1	BS-12-B2AA002
4.7uF	C1	C0402	1	CL05A475MP5NRNC
10uF	C2-C18	C0402	7	CL05A106MQ5NUNC
100nF	C3-58	C0402	31	CL05B104KO5NNNC
100uF	C7	L3.5-W2.8	1	TAJB107K006RNJ
22uF	C10	C0603	1	CL10A226MQ8NRNC
22pF	C21-23,C33	C0402	4	0402CG220J500NT
47uF	C25,C27,C60	C0805	3	CL21A476MQYNNNE
1nF	C31,C61	C0402	2	0402B102K500NT
1N148	D2	SOD-323	1	1N4148WS
ZMM3V3	D3	LL-34	1	ZMM3V3-M
ZMM5V6	D4	LL-34D	1	ZMM5V6-M
Ferrite Bead 800ma	FB1	FB0805	1	GZ2012D101TF
XC6220B331MR-G	LDO1	SOT-25-5	1	XC6220B331MR-G
XC6206P332MR	LDO2	SOT-23-3	1	XC6206P332MR
WS2812B	LED1-32	3535RGB	22	XL-3535RGBC-WS2812
RTC	LED33	LED0603	1	KT-0603R
3V3_SCD4x	LED36	LED0603	1	19-217/GHC-YR1S2/3T
3V3	LED103	LED0603	1	19-217/GHC-YR1S2/3T
RX	LED104	LED0603	1	19-213/Y2C-CQ2R2L
TX	LED105	LED0603	1	19-213/Y2C-CQ2R2L
IO2	LED106	LED0603	1	KT-0603R
SN74LV1T34DBVR	LS1	SOT-23-5	1	SN74LV1T34DBVR
100kΩ	R1,R5,R14,R15	R0402	4	0402WGF1003TCE
100Ω	R2,R4	R0402	2	0402WGF1000TCE
10kΩ	R3,R6-R9,R25	R0402	6	0402WGF1002TCE
200kΩ	R10,R16	R0402	2	0402WGF2003TCE
200Ω	R11	R0402	1	0402WGF2000TCE
1MΩ	R13	R0402	1	0402WGF1004TCE
330Ω	R17	R0402	1	0402WGF3300TCE
5.1kΩ	R18,R19	R0402	2	0402WGF5101TCE
4.7kΩ	R29,R30	R0402	2	0402WGF4701TCE
LTR303 Lux	U4	SOT-363	1	LTR-303ALS-01
PCF8563T RTC	U6	SOIC-8	1	PCF8563T/5,518
918-418K2024S40004	USBC1	USB-C-SMD	1	918-418K2024S40004
32.768kHz	X1	FC-135R	1	Q13FC1350000400

✌️ Other

Some of the foundational work was done as part of a project with Terrestrial Assemblages with the support of Govett-Brewster Art Gallery / Len Lye Centre.

Thanks to everyone at @Espressif Systems for making a really awesome chip and porting it to Arduino.

Thanks to @LTRTNZ for putting up with my never-ending shit and @vincentd123 for helping me.

Made with love by Chris Dirks (@cd_fer) in Aotearoa New Zealand.