Montage
For the creators of a Zephyr network.
Case assembly
After printing the 7 parts that make up the case, use an M5 tap to tap the 3 threads on the case cap. The threads have been pre-formed during printing, but it's necessary to finish tapping them. You can also use a moderately heated threaded rod to tap each hole.
If you have cut the threaded rods with a hacksaw, you will have taken care to file the bevelled ends with a file or grinding wheel to facilitate screwing on the nuts.
Screw in each threaded rod, adding a little cyanoacrylate glue to lock them in place.
Thread the 4 intermediate parts of the case into the rods screwed to the case cap.
Place the central hexagonal screw on the sensor base, then glue the SEN55 sensor support in the slot provided.
Once glued, the sensor support no longer allows the screw to be fitted.
Mounting the sensors on the PCB
The wiring
Have a PCB printed by a specialist company using the gerber file supplied (for example), or make your own.
PCB preparation
Solder the wires of the JST GHR 06V-S connector according to the wiring diagram provided by Sensirion. Solder the FH1XT connectors to the PCB. 2 x 7-pin connectors for the Xiao ESP32 C3 and possibly 1 x 4-pin connector for the SCD30 option.
1
5V
VCC
-
a
2
GND
GND
-
b
3
SDA (pin 4)
SDA
SDA
c
4
SCL (pin 5)
SCL
SCL
d
5
GND
GND
GND
b
-
3.3V
-
VCC
e
Sensor connection
Connect the SEN55 sensor to the Xiao ESP32 C3 board and, if necessary, the SCD30 sensor. Before placing the assembly in the box, we recommend connecting it to a computer to check that it works properly, and then downloading the final code.
Hardware control and code upload
Before this step can be finalized, the code to be uploaded must be set according to the characteristics of the network that will centralize the data.(cf § Gestion des données).
Once you've customized the code, upload it and check that the hardware and connection are working properly.
Download
Under Visual Studio Code, install the project code files customized to the characteristics of your network, as well as the Include folder with the SEN55-<SENSOR_ID> or SCD30-<SENSOR_ID> files for each sensor, containing the parameters specific to each one.
To download the code from plateformIO to the Xiao EPS32 C3 card, hold down the Bootloader push-button on the Xiao card while you connect the USB C cable to the computer. Use a stylus or a small wand (cf. les fichiers STL d'impression 3D) to press this button.
Set the code according to (see image above):
A: specify the include .h file of the sensor to be installed. Here SEN55-084.h
B: "SCD30 0" if the Zephyr is not equipped with an SCD30 sensor,"SCD30 1" otherwise
C: "WIFI_RESET 0" to retain saved wifi settings, or select "1" to reset wifi settings.
D: "SEND_DATA 0" to record data every half-hour, "SEND_DATA 1" to record data every 5 minutes.
E: "DEBUG 1": to display serial.print information on the monitor for checking,"DEBUG 0"in normal mode
Upload the code ( arrow command -> ), after a few seconds (13.15 sec. here) Visual Studio Code indicates whether the upload was successful.
Disconnect and reconnect the Xiao card (or press the Reset button on the card) and check the available wifi networks on a computer or smartphone. Look for the new network generated by the Zephyr, calledLook for the new network generated by the Zephyr called "AutoConnectApp" usually appears on your device, if not open a web browser and go to http://192.168.4.1 . This temporary network will enable you to connect the Zephyr to the home box's wifi. Connect to this network, then press Configure WIFI.
A new screen will appear. It will list the SSIDs of all available wifi networks. Choose the network to which you want to connect the Zephyr (here "My SSID") and enter the network password.
Check your password carefully (check Show Password).
an incorrect password would force you to restart the entire installation procedure
Then press "Save" to confirm your choice. Disconnect and reconnect the Xiao card. Go to your project dashboard (Grafana, for example) to check whether data is being sent by this Zephyr. If the Zephyr is sending data (wait between 2 and 5 minutes), all is well. All you need to do now is reset the code if you're not at the sensor's final installation location. To reset the code, first upload the code by selecting parameter C "WIFI_RESET 1" to erase the login credentials. Then upload the same code again with the following parameters:
B: "SCD30 0" if the Zephyr is not equipped with an SCD30 sensor,"SCD30 1" otherwise
C: "WIFI_RESET 0"
D: "SEND_DATA 0" to record data every half-hour, or "SEND_DATA 1" to record data every 5 minutes.
E: "DEBUG 0"
This sensor is then ready to be configured to the Wifi network of the location where it will be installed, by repeating the procedure with the AutoConnectApp application as before. (cf. le Mode d'emploi) .
Be sure to configure the WIFI_RESET 0, otherwise, each time the Zephyr is reset, the program will ask to be reconfigured to the Wifi network.
In case of malfunction
If the check is negative, check the connection status, the downloaded code, the wiring and the Zephyr hardware. Of the hundred or so SEN55 sensors we've installed, none has malfunctioned, but the connection to the Xiao and the Xiao board itself can fail, even if this is rare.
Final assemblage
Place the SEN55 in its bracket and the PCB in its housing on the base. To hold the PCB in place while allowing it to be easily dismantled, you can block it with 2 pieces of toothpick (red arrows in the previous photo).
If necessary, you can add a dab of hot-melt glue (avoid cyanoacrylate gel, which will make disassembly more difficult). Connect the JST GHR connector to the SEN55. Fit the SCD30 sensor if required. Secure the bracket with the hex head screws and nuts. Insert the base into the upper housing, fit the washers and screw the wing nuts onto the 3 threaded rods. The Zephyr sensor is now ready. All that remains is to configure it on the home wifi network where it will be installed.(cf. la procédure dans le § Mode d'emploi) and fasten it to the front panel.
It is advisable to note the sensor's unique identifier on the bottom of the case and on the PCB, to link the sensor to the locality where it is to be installed. The identifier is the name of the include .h file. <SEN55_SENSOR_ID> .
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