Device assembly - Revision history

Bcmwiki: Update: V1/V2 naming, remove ESP32/Pi distinction

2026-03-08T13:21:08Z

Update: V1/V2 naming, remove ESP32/Pi distinction

← Older revision		Revision as of 13:21, 8 March 2026
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	{{Note\|1='''Legacy V1 Documentation''' — This page documents assembly of the ~~Raspberry Pi-based~~ bcMeter V1. The current platform ~~uses ESP32-S3~~. V1 assembly instructions are preserved here for reference.}}		{{Note\|1='''Legacy V1 Documentation''' — This page documents assembly of the bcMeter V1. The current V2 platform has a different hardware design. V1 assembly instructions are preserved here for reference.}}

	'''bcMeter V1 Assembly Documentation''' (v02, January 2025)		'''bcMeter V1 Assembly Documentation''' (v02, January 2025)

Bcmwiki: Wiki update: sync with manual and dev docs (2026-03)

2026-03-08T13:10:15Z

Wiki update: sync with manual and dev docs (2026-03)

← Older revision		Revision as of 13:10, 8 March 2026
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	{{~~bcMeter Assembly Documentation~~		{{Note\|1='''Legacy V1 Documentation''' — This page documents assembly of the Raspberry Pi-based bcMeter V1. The current platform uses ESP32-S3. V1 assembly instructions are preserved here for reference.}}
	\| ~~version~~ = ~~v02~~
	~~\| date = 31~~.01.~~2025~~
	}}

	'''bcMeter ~~2025~~ Assembly Documentation'''		'''bcMeter V1 Assembly Documentation''' (v02, January 2025)

	== LED and Sensor Brackets ==		== LED and Sensor Brackets ==


	The orientation of both the 3D printed infrared LED and sensor assemblies has been simplified to reduce orientation mismatches.		The orientation of both the 3D printed infrared LED and sensor assemblies has been simplified to reduce orientation mismatches.
Line 15:		Line 11:
	* '''Glueing:''' Use plastics glue (avoid "super glue" as it can leave residue that affects LED and phototransistor sensitivity for days or weeks). Place a droplet of glue on each leg to close the hole.		* '''Glueing:''' Use plastics glue (avoid "super glue" as it can leave residue that affects LED and phototransistor sensitivity for days or weeks). Place a droplet of glue on each leg to close the hole.

	* '''Assembly:'''		* '''Assembly:'''
	* Insert the LED and sensor bracket assembly into the case.		** Insert the LED and sensor bracket assembly into the case.
	* Pre-treat both counterparts with plastics glue before insertion to create airtight channels.		** Pre-treat both counterparts with plastics glue before insertion to create airtight channels.
	* Ensure the middle section between the sample and sensor areas is completely covered with glue to prevent air leakage.		** Ensure the middle section between the sample and sensor areas is completely covered with glue to prevent air leakage.
	* '''Fixing:''' Prior to insertion, secure the LEDs and sensors with plastic or hot glue (avoid tilting; check orientation).		* '''Fixing:''' Prior to insertion, secure the LEDs and sensors with plastic or hot glue (avoid tilting; check orientation).
	* '''Mounting:''' Once inserted, mount the brackets to the case and verify that the LED and sensor lenses are centered.		* '''Mounting:''' Once inserted, mount the brackets to the case and verify that the LED and sensor lenses are centered.

	~~[[File:LED and Sensor brackets.png\|frameless\|left]]~~		== Reference & Sample Parts ==
	~~[[File:Plastic glue to create airtight channels.png\|frameless\|left]]~~

			On the circuit board, the LEDs must be connected in series. The negative pin of the first LED serves as the positive pin for the second LED. Use a standard 4-pin 2.54 mm JST connector and cable, soldering the connections in the order:

	~~== Reference & Sample Parts ==~~		: '''red – black – yellow – white''' - connect one by one. If your cable has different coloring, maintain the same electrical order.
	~~On the circuit board, the LEDs must be connected in series. The negative pin of the first LED serves as the positive pin for the second LED. Use a standard 4~~-~~pin 2~~.~~54 mm JST connector and~~ cable, ~~soldering the connections in~~ the order

	~~[[File~~:~~LED and Sensor wiring.jpg\|thumb\|frameless\|left]]~~		The infrared sensors (for measuring attenuation) are connected '''in parallel'''. Their connections follow a different order:

			: '''black – red – white – yellow'''
	:'''red – ~~black~~ – yellow ~~– white~~''' ~~- connect one by one. If your order of cables has another coloring, adhere to that.~~

	~~The infrared sensors (used for measuring attenuation) are connected '''in parallel''~~. ~~Their connections must follow a different order from~~ the ~~LEDs, given the same color order:~~		This completes the most crucial part of the bcMeter assembly. LED-to-sensor orientation and air leakage directly affect accuracy. Minor misalignments can be compensated by the [[Maintenance#Calibration\|Calibration function]].

	~~:'''black – red – white – yellow'''~~

			== Sealing ==

	~~This completes the most crucial part of the bcMeter~~ assembly~~, as the LED-~~to~~-sensor orientation and air leakage directly affect~~ the ~~device’s later accuracy. Minor misalignments are unavoidable but can be compensated by the "Calibration" function in the interface.~~		Continue case assembly by adding a rubber seal to the bottom part:

	~~== Sealing ==~~		* Ensure the seal's diameter is precisely known — critical for accuracy.
	~~Continue the case assembly by adding a rubber seal to the bottom part. Key points include:~~		* Check for air leakage; if needed, apply a second seal to the top part and ensure holes overlap.
			* To verify diameter, let the paper run black and examine the sample spot.
	* Ensure the ~~seal’s~~ diameter is precisely ~~known—it is~~ critical for accuracy.		* Add M3 screw threads to the poles and use superglue to secure them.
	* Check for air leakage; if needed, apply a second seal to the top part and ensure ~~the~~ holes overlap.
	* To verify ~~the~~ diameter, let the paper run black and examine the sample ~~spot’s form and size~~.
	* Add M3 screw threads to the poles and use superglue to secure ~~the connection~~.

	== Pump Control Circuit ==		== Pump Control Circuit ==
	~~The bcMeter is versatile with pump selection. Any pump that can run at 5V will work. There are two low-cost pump types:~~

	* '''Membrane pumps''' – Recommended for this use case.
	* '''Propeller pumps'''

	Membrane pumps can ~~either~~ use a PWM controller (Type A) or operate without one (Type B)~~. The bcMeter can handle both; simply connect the pump to the PCB~~. For PWM-controlled pumps, ~~remember to~~ remove Q4.		The bcMeter is versatile with pump selection. Any pump running at 5V will work. Two low-cost types:

			* '''Membrane pumps''' — Recommended.
			* '''Propeller pumps''' — Not recommended for this use case.

			Membrane pumps can use a PWM controller (Type A) or operate without one (Type B). For PWM-controlled pumps, remove Q4 from the PCB.

	== Airflow Meter Setup ==		== Airflow Meter Setup ==
	If an airflow meter is used~~, configure the connections as follows~~:
			If an airflow meter is used:
	* Connect the ~~pump’s~~ input to the airflow ~~sensor’s~~ output.
	* Connect the airflow ~~sensor’s~~ input to the air sampling connector.		* Connect the pump's input to the airflow sensor's output.
	* Connect the ~~pump’s~~ output to the ~~bcMeter’s~~ air output ~~(note that the exact connection may vary with case revision)~~.		* Connect the airflow sensor's input to the air sampling connector.
			* Connect the pump's output to the bcMeter's air output.

	== Finalizing the Build ==		== Finalizing the Build ==
	* Insert ~~the~~ filter paper and screw the top part of the case by hand.
			* Insert filter paper and screw the top part of the case by hand.
	* Connect a stronger 12V pump and cover the air inlet.		* Connect a stronger 12V pump and cover the air inlet.
	* If ~~any~~ noise is heard (indicating leakage), use glue to seal the gap.		* If noise is heard (indicating leakage), use glue to seal the gap.

			== Description of the Components (V1 PCB) ==

	~~== Description of the Components ==~~
	* '''U1:''' MCP3428 4-Channel Analogue/Digital Converter		* '''U1:''' MCP3428 4-Channel Analogue/Digital Converter
	* '''D1 / D2:''' IR LED connector for sensor and reference		* '''D1 / D2:''' IR LED connector for sensor and reference
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	* '''J4 / J9:''' PWM + Power for Air Pump (remove Q4 for PWM pump)		* '''J4 / J9:''' PWM + Power for Air Pump (remove Q4 for PWM pump)
	* '''Additional:''' Several headers (I2C, ADC, Power) for expandability		* '''Additional:''' Several headers (I2C, ADC, Power) for expandability

	~~== Case Assembly Overview ==~~
	~~For the final assembly, refer to the detailed instructions above covering:~~
	* Pump control circuit
	* Final build adjustments
	* Component descriptions

	~~== See Also ==~~
	* [[bcMeter Assembly Guide]]
	* [[Pump Control Circuit Design]]

Bcmwiki: Created page with "{{bcMeter Assembly Documentation | version = v02 | date = 31.01.2025 }} '''bcMeter 2025 Assembly Documentation''' == LED and Sensor Brackets == The orientation of both..."

2025-03-11T09:33:27Z

Created page with "{{bcMeter Assembly Documentation | version = v02 | date = 31.01.2025 }} '''bcMeter 2025 Assembly Documentation''' == LED and Sensor Brackets == The orientation of both..."

New page

{{bcMeter Assembly Documentation
| version = v02
| date = 31.01.2025
}}

'''bcMeter 2025 Assembly Documentation'''

== LED and Sensor Brackets ==

The orientation of both the 3D printed infrared LED and sensor assemblies has been simplified to reduce orientation mismatches.

The infrared LEDs are housed in clear-looking parts while the infrared sensors are in dark parts. Each must be correctly oriented – note that the spherical lens on each part should point toward the shorter end of the bracket, ensuring both point toward the filter paper.

* '''Glueing:''' Use plastics glue (avoid "super glue" as it can leave residue that affects LED and phototransistor sensitivity for days or weeks). Place a droplet of glue on each leg to close the hole.

* '''Assembly:'''
* Insert the LED and sensor bracket assembly into the case.
* Pre-treat both counterparts with plastics glue before insertion to create airtight channels.
* Ensure the middle section between the sample and sensor areas is completely covered with glue to prevent air leakage.
* '''Fixing:''' Prior to insertion, secure the LEDs and sensors with plastic or hot glue (avoid tilting; check orientation).
* '''Mounting:''' Once inserted, mount the brackets to the case and verify that the LED and sensor lenses are centered.

[[File:LED and Sensor brackets.png|frameless|left]]
[[File:Plastic glue to create airtight channels.png|frameless|left]]

== Reference & Sample Parts ==
On the circuit board, the LEDs must be connected in series. The negative pin of the first LED serves as the positive pin for the second LED. Use a standard 4-pin 2.54 mm JST connector and cable, soldering the connections in the order

[[File:LED and Sensor wiring.jpg|thumb|frameless|left]]

:'''red – black – yellow – white''' - connect one by one. If your order of cables has another coloring, adhere to that.

The infrared sensors (used for measuring attenuation) are connected '''in parallel''. Their connections must follow a different order from the LEDs, given the same color order:

:'''black – red – white – yellow'''

This completes the most crucial part of the bcMeter assembly, as the LED-to-sensor orientation and air leakage directly affect the device’s later accuracy. Minor misalignments are unavoidable but can be compensated by the "Calibration" function in the interface.

== Sealing ==
Continue the case assembly by adding a rubber seal to the bottom part. Key points include:

* Ensure the seal’s diameter is precisely known—it is critical for accuracy.
* Check for air leakage; if needed, apply a second seal to the top part and ensure the holes overlap.
* To verify the diameter, let the paper run black and examine the sample spot’s form and size.
* Add M3 screw threads to the poles and use superglue to secure the connection.

== Pump Control Circuit ==
The bcMeter is versatile with pump selection. Any pump that can run at 5V will work. There are two low-cost pump types:

* '''Membrane pumps''' – Recommended for this use case.
* '''Propeller pumps'''

Membrane pumps can either use a PWM controller (Type A) or operate without one (Type B). The bcMeter can handle both; simply connect the pump to the PCB. For PWM-controlled pumps, remember to remove Q4.

== Airflow Meter Setup ==
If an airflow meter is used, configure the connections as follows:

* Connect the pump’s input to the airflow sensor’s output.
* Connect the airflow sensor’s input to the air sampling connector.
* Connect the pump’s output to the bcMeter’s air output (note that the exact connection may vary with case revision).

== Finalizing the Build ==
* Insert the filter paper and screw the top part of the case by hand.
* Connect a stronger 12V pump and cover the air inlet.
* If any noise is heard (indicating leakage), use glue to seal the gap.

== Description of the Components ==
* '''U1:''' MCP3428 4-Channel Analogue/Digital Converter
* '''D1 / D2:''' IR LED connector for sensor and reference
* '''Q1 / Q2:''' IR Phototransistor for sensor and reference (ADC Channels 1 and 2)
* '''J1:''' Omron D6F Airflow Sensor (ADC Channel 4)
* '''J2:''' SSD1306 Display (optional)
* '''J7:''' Heater or Fan (optional)
* '''J12:''' SPI Header (optional)
* '''J5:''' Air Pump
* '''J4 / J9:''' PWM + Power for Air Pump (remove Q4 for PWM pump)
* '''Additional:''' Several headers (I2C, ADC, Power) for expandability

== Case Assembly Overview ==
For the final assembly, refer to the detailed instructions above covering:
* Pump control circuit
* Final build adjustments
* Component descriptions

== See Also ==
* [[bcMeter Assembly Guide]]
* [[Pump Control Circuit Design]]