I’d be very keen on the designs to print my own PCB and populate myself. Not personally too keen on the CO2 sensors; but might populate a single device as to get some information.
Been toying with the idea of having a sensor-set per room as well. Must-haves for me include temperature, ambient light sensor and in some cases the IR Tx feature. I do however think the IR Rx could be used for lots of things.
Cool project!
I like this idea for an simple basic board per room (temperature, ambient light sensor) IR is not useful in all rooms.
Just 1 basic board to keep the cost down and then some optional add-on like IR or CO2 sensors that you could plug in.
Keep me posted!
@5310 It’s going to be powered via the USB connector on the side with a generic 5v usb adapter.
@prosty I will share schematics and everything else after testing the boards so that you can work on your version.
I also thought of making a version without a CO2 sensor since the cost of the sensor exceeds the cost of all other components altogether. For now I think I’ll just use the same PCB without soldering the CO2 sensor, maybe later on I could design another board but for now I’ll use this as it is already very small.
@elRadix I agree with the possibility of having the CO2 sensor as an option as it is very expensive and not necessarily useful for everyone. I think that if I start assembling the boards and sell them through tindie there will be the option to buy one without the CO2 sensor (you can always buy it later and solder it if you change your mind), while for infrared I do not think it is worth creating an option without it as the cost is around $ 0.40 for receiver and transmitter.
@Nico Even though everyone has their own ideas of what should go onto the board, I guess one should be able to populate only what you want. As you mentioned ; one without a CO2. I’d say the rest of the components would work the same. Don’t populate an IR LED if you don’t need one and don’t populate the power LEDs or buttons if you think you can get away without them…
Once ready, might be good to again list the recommended components for the board and where you sourced them.
@prosty Maybe you didn’t understand exactly what I meant, when I was talking about options I meant that when I will probably open a Tindie store I will create two versions, a complete one and a cheaper one without the CO2 sensor.
Sure everyone is free to produce the board as they prefer, I shared the project exactly for this reason. In the future I will share the gerber files and the BOM for the PCB but also the schematics so that it can be taken and modified at will.
@Nico Curiosity question… I haven’t played with CO2 sensors yet, but from the little I have read they use infrared to detect the CO2 level. Working with ESP32, especially if they are BLE scanning, they produce some heat during operation.
I’m wondering, not being a party pooper here… Could the heat from the ESP32 affect the CO2 sensor, I know, depending on the board layout and the case that it can affect the temperature sensor.
I’m very curious what you thoughts are. Frankly, I wonder if it is even a problem?
@ronytomen This is actually a good observation, for the CO2 sensor there should be no problems because it contains a temperature sensor for automatic compensation.
For the temperature sensor, I placed both the ESP and the voltage regulator on the opposite side of the board exactly for this reason, also the ground planes are connected on both sides to help dissipate the heat. I will still have to test everything as soon as the boards arrive and if necessary find a better solution.
I also know that it is possible to enable a power saving wireless mode on the ESP to reduce the heat to be dissipated, but frankly I have not yet looked much into this.
I do remember Otto of ESPHome mentioning somewhere that WIFI power savings can cause some problems with connectivity. I just don’t recall the details.
I haven’t pulled the trigger on implementing CO2 sensors, to many projects in the queue. 
Hopefully the board will offer enough insulation for the temperature sensor. A well thought out case might help mitigate heat as well.
Would it be possible to add a PIR sensor on there as well?
seems to me it would be desirable to leave a few pins exposed for people to add whatever they like by way of sensors, or even a couple of grove connectors for a no solder solution.
@R4m80 @nickrout At first I thought of adding a PIR, but since I didn’t test any sensors and wanted to keep the board as small as possible, I left this idea aside for now.
For sure in a second board revision I could add a PIR and a grove connector (I had not thought of the grove connector, thanks for the idea), but before proceeding with these things I still have to wait to receive the boards and test that everything works.
Interesting project… following for updates.
following!
Any update on selling the boards? I’m very interested
I was going to try to do something similar but why reinvent the wheel. I would love to hear more about your progress.
Sorry for the long inactivity but between university studies and the situation of the last months the development of this project has slowed down.
The last (hopefully) revision is now in the production phase and I am waiting to receive it for testing.
The board has been completely redesigned, all the components are now on one side only to facilitate assembly, it should be easier for those who want to try to make one, and a PIR sensor has been added as proposed by some of you.
Unfortunately the CO2 sensor has been removed as it is too expensive (more than the cost of the whole board and components) and for other small problems. I tested some other integrated sensors like BME680, CCS811 and SGP30 but with not enough satisfactory results. I decided to remove this sensor for now but I am willing to integrate it again in case I find a valid option in the future. The IR sensors and transmitters were also removed as the range of the chosen transmitters was not sufficient and required the board to be aligned and positioned very close to the receiver.
Regarding the request to produce and sell these boards, I’m still considering how to do it since unfortunately I don’t have the time to assemble and test the boards by hand. I have just ordered a small batch of already assembled boards to test the service. If everything works as planned I should be able to make larger orders in the future and sell them through Tindie. I will keep you updated on this.
Here’ s a little spoiler of the new board
Once received and tested the first prototypes I will share the project and more information with you.
That looks awesome. Cant wait for your feedback on how it runs and hopefully you would be able to sell these fully assembled boards on Tindie. Well done with your project.
Any updates on this?
Since the design has changed slightly from what I initially thought, I created a new thread to make it a little more clear.
