Assembly - Revision history

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

2026-03-08T13:10:08Z

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

← Older revision		Revision as of 15:10, 8 March 2026
Line 1:		Line 1:
	~~__FORCETOC__~~		#REDIRECT [[Device assembly]]

	{{#~~ev: vimeo \| 684373327 \| 1000px }}~~

	~~== Overview of parts / Assembly ==~~

	~~'''Requirements:~~
	~~# Screwdriver~~
	~~# Solder Iron~~
	~~# Solder~~
	~~# Flux~~
	~~# 3D Printer / 3d printing service~~



	~~LED and sensor brackets~~
	[[~~File:Image_001.png\|thumb\|none]]~~

	~~The orientation of both the 3D printed infrared LED and sensor assemblies have been simplified to reduce orientation mismatches.~~
	~~The infrared LEDs come in a clear looking part while the infrared sensors are dark parts.~~
	~~Each part needs to be correctly oriented; they have an spherical shaped part (lenses) which needs to point to the shorter end of the 3D printed brackets in~~
	~~a way that they both point to the filter paper.~~

	~~Insert LED and sensor bracket~~ assembly ~~to the case~~
	~~[[File:Image_002.png\|thumb\|none]]~~

	Prepare both the counterparts for the LED and sensor bracket assemblies with superglue or hot glue before insertion to create airtight channels. Make sure to also completely cover the middle part between sample and sensor area with glue. This is absolutely crucial to avoid air leakage.
	~~Before inserting the brackets into the case, use superglue to fix the LEDs and sensors in place (avoid tilting and~~
	~~[[File:Image_003.png\|thumb\|none]]~~

	~~check orientation).~~
	Mount the brackets to the case and check that the lenses of are centered in the holes by looking straight from above; same goes for the dark infrared sensors in their bracket to be inserted in the bottom case.
	~~You have a little while to adjust with superglue; using hot glue, reheat the area as needed:~~
	~~Clean possible residue of glue with acetone as it aﬀects the clarity of the LEDs.~~
	~~Reference & Sample parts~~
	~~[[File:Image_004.png\|thumb\|none]]~~

	In this area on the circuit board, the LEDs have to be connected in series, so the negative pin of the first LED is the positive pin of the second LED. Using a standard 4 pin 2.54mm JST connector and cable, solder the connections in the order red- black-yellow-white.

	~~[[File:Image_005.png\|thumb\|none]]~~

	~~Here, the infrared sensors for measuring the attenuation are connected parallel. Thus, they have to be connected in a diﬀerent order than the LEDS: black-red-white-yellow.~~
	Now, you have completed the most crucial part of the bcMeter assembly. The orientation of the LEDs to the sensors and the air leakage have a huge influence on the later accuracy of the device. Smaller isalignments can't be avoided and compensated by the "Calibration" function from the interface.
	~~Sealing~~
	~~[[File:Image_006.jpg\|thumb\|none]]~~

	~~Now we can continue assembling the case itself by adding the rubber seal onto the bottom part. Make sure that the diameter is very well known as this is a crucial parameter for accuracy.~~
	~~Check for air leakage and if needed, add a second seal on the top part as well. Make sure that the holes a overlapping.~~
	~~To verify the diameter, you can just let the paper run black and then check the form and size of the sample spot.~~
	~~Also add the M3 screw threads to the poles and use superglue to make a solid connection.~~

	~~‌Pump control circuit~~

	~~[[File:Image_007.jpg\|thumb\|none]]~~


	~~The bcMeter is very forgiving in choosing pumps since I tested and used every available type.~~
	Basically you can connect every pump you want which is able to run at 5V. There are two type pumps in the low cost range: Membrane and propeller. For our use case, we need the membrane pumps. Then, they can have a PWM controller (Type A) or run without (Type B). The bcMeter is able to handle both types of pump and you can just connect them to the PCB. For PWM pumps, remove Q4.
	~~image~~
	~~image~~
	~~If you want to use an airflow meter, connect the input of the pump to the output of the airflow sensor as shown on the left.~~
	~~The input of the airflow sensor needs to be connected to the air sampling connector.~~
	~~The pump output needs to be connected to the air output of the bcMeter as shown on the right.~~

	~~‌Finalizing the built~~
	~~Screw the top part of the case handtight~~


	~~[[File:Image_008.jpg\|thumb\|none]]~~
	~~[[File:Image_009.png\|thumb\|none]]~~
	~~[[File:Image_010.png\|thumb\|none]]~~

	~~[[File:Image_011.png\|thumb\|none]]~~

	~~‌Technical overview of the PCB:~~

	~~[[File:Image_012.png\|thumb\|none~~]]

	~~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 Channel 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: PWM + J9 Power for Air Pump (Remove Q4 for PWM Pump!)~~

	~~+ several header (I2C, ADC, Power) for expandability~~

Bcmwiki at 19:33, 13 October 2024

2024-10-13T19:33:37Z

← Older revision		Revision as of 21:33, 13 October 2024
Line 3:		Line 3:
	{{#ev: vimeo \| 684373327 \| 1000px }}		{{#ev: vimeo \| 684373327 \| 1000px }}

	== Overview of parts ==		== Overview of parts / Assembly ==

	'''Requirements:		'''Requirements:
Line 13:		Line 13:


	~~bcMeter 2024 Prototype documentation 20.05.2024~~
	LED and sensor brackets		LED and sensor brackets
	[[File:Image_001.png\|thumb\|none]]		[[File:Image_001.png\|thumb\|none]]

Bcmwiki at 19:33, 13 October 2024

2024-10-13T19:33:14Z

← Older revision		Revision as of 21:33, 13 October 2024
Line 11:		Line 11:
	# Flux		# Flux
	# 3D Printer / 3d printing service		# 3D Printer / 3d printing service


			bcMeter 2024 Prototype documentation 20.05.2024
			LED and sensor brackets
			[[File:Image_001.png\|thumb\|none]]

			The orientation of both the 3D printed infrared LED and sensor assemblies have been simplified to reduce orientation mismatches.
			The infrared LEDs come in a clear looking part while the infrared sensors are dark parts.
			Each part needs to be correctly oriented; they have an spherical shaped part (lenses) which needs to point to the shorter end of the 3D printed brackets in
			a way that they both point to the filter paper.

			Insert LED and sensor bracket assembly to the case
			[[File:Image_002.png\|thumb\|none]]

			Prepare both the counterparts for the LED and sensor bracket assemblies with superglue or hot glue before insertion to create airtight channels. Make sure to also completely cover the middle part between sample and sensor area with glue. This is absolutely crucial to avoid air leakage.
			Before inserting the brackets into the case, use superglue to fix the LEDs and sensors in place (avoid tilting and
			[[File:Image_003.png\|thumb\|none]]

			check orientation).
			Mount the brackets to the case and check that the lenses of are centered in the holes by looking straight from above; same goes for the dark infrared sensors in their bracket to be inserted in the bottom case.
			You have a little while to adjust with superglue; using hot glue, reheat the area as needed:
			Clean possible residue of glue with acetone as it aﬀects the clarity of the LEDs.
			Reference & Sample parts
			[[File:Image_004.png\|thumb\|none]]

			In this area on the circuit board, the LEDs have to be connected in series, so the negative pin of the first LED is the positive pin of the second LED. Using a standard 4 pin 2.54mm JST connector and cable, solder the connections in the order red- black-yellow-white.

			[[File:Image_005.png\|thumb\|none]]

			Here, the infrared sensors for measuring the attenuation are connected parallel. Thus, they have to be connected in a diﬀerent order than the LEDS: black-red-white-yellow.
			Now, you have completed the most crucial part of the bcMeter assembly. The orientation of the LEDs to the sensors and the air leakage have a huge influence on the later accuracy of the device. Smaller isalignments can't be avoided and compensated by the "Calibration" function from the interface.
			Sealing
			[[File:Image_006.jpg\|thumb\|none]]

			Now we can continue assembling the case itself by adding the rubber seal onto the bottom part. Make sure that the diameter is very well known as this is a crucial parameter for accuracy.
			Check for air leakage and if needed, add a second seal on the top part as well. Make sure that the holes a overlapping.
			To verify the diameter, you can just let the paper run black and then check the form and size of the sample spot.
			Also add the M3 screw threads to the poles and use superglue to make a solid connection.

			‌Pump control circuit

			[[File:Image_007.jpg\|thumb\|none]]


			The bcMeter is very forgiving in choosing pumps since I tested and used every available type.
			Basically you can connect every pump you want which is able to run at 5V. There are two type pumps in the low cost range: Membrane and propeller. For our use case, we need the membrane pumps. Then, they can have a PWM controller (Type A) or run without (Type B). The bcMeter is able to handle both types of pump and you can just connect them to the PCB. For PWM pumps, remove Q4.
			image
			image
			If you want to use an airflow meter, connect the input of the pump to the output of the airflow sensor as shown on the left.
			The input of the airflow sensor needs to be connected to the air sampling connector.
			The pump output needs to be connected to the air output of the bcMeter as shown on the right.

			‌Finalizing the built
			Screw the top part of the case handtight


			[[File:Image_008.jpg\|thumb\|none]]
			[[File:Image_009.png\|thumb\|none]]
			[[File:Image_010.png\|thumb\|none]]

			[[File:Image_011.png\|thumb\|none]]

			‌Technical overview of the PCB:

			[[File:Image_012.png\|thumb\|none]]

			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 Channel 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: PWM + J9 Power for Air Pump (Remove Q4 for PWM Pump!)

			+ several header (I2C, ADC, Power) for expandability

Bcmwiki: Replaced content with "FORCETOC {{#ev: vimeo | 684373327 | 1000px }} == Overview of parts == '''Requirements: # Screwdriver # Solder Iron # Solder # Flux # 3D Printer / 3d printin..."

2024-10-13T19:26:17Z

Replaced content with "__FORCETOC__ {{#ev: vimeo | 684373327 | 1000px }} == Overview of parts == '''Requirements: # Screwdriver # Solder Iron # Solder # Flux # 3D Printer / 3d printin..."

Show changes

Bcmwiki at 19:24, 13 October 2024

2024-10-13T19:24:38Z

← Older revision		Revision as of 21:24, 13 October 2024
Line 1:		Line 1:
	__FORCETOC__		__FORCETOC__

	<vimeo ~~w="800">~~684373327~~</vimeo>~~		{{#ev: vimeo \| 684373327 \| 1000px }}

	== Overview of parts ==		== Overview of parts ==

Bcmwiki at 19:22, 13 October 2024

2024-10-13T19:22:55Z

← Older revision		Revision as of 21:22, 13 October 2024
Line 1:		Line 1:
	__FORCETOC__		__FORCETOC__

			<vimeo w="800">684373327</vimeo>

	== Overview of parts ==		== Overview of parts ==

Line 12:		Line 15:
	== Component locations 5V bcMeter PCB ==		== Component locations 5V bcMeter PCB ==

	~~<vimeo>684373327</vimeo>~~ Introduction to bcMeter 5V		Introduction to bcMeter 5V

Bcmwiki: /* Overview of parts */

2024-10-13T19:11:21Z

Overview of parts

← Older revision		Revision as of 21:11, 13 October 2024
Line 1:		Line 1:
	__FORCETOC__		__FORCETOC__
	== Overview of parts ==		== Overview of parts ==
	~~[[File:Overview.jpg\|500px\|left]]<br clear=all>~~

	'''Requirements:		'''Requirements:
Line 10:		Line 9:
	# 3D Printer / 3d printing service		# 3D Printer / 3d printing service
	# [[bcMeter Parts]]		# [[bcMeter Parts]]


	== Component locations 5V bcMeter PCB ==		== Component locations 5V bcMeter PCB ==

Bcmwiki at 19:10, 13 October 2024

2024-10-13T19:10:24Z

← Older revision		Revision as of 21:10, 13 October 2024
Line 81:		Line 81:
	\|}		\|}

	~~== Component locations 12V general purpose PCB (big) ==~~
	~~(We recommend to use the 5V pcb - the big PCB is easier to assemble at the cost of accuracy)~~

	~~{\| role="presentation" class="wikitable mw-collapsible mw-collapsed sortable"~~
	~~! Ref !! Value !! Part !! Footprint !! Description !! Vendor~~
	\|-
	~~\| C1 \|\| 330nF \|\| Device:CP \|\| Capacitor_THT:CP_Radial_D5.0mm_P2.50mm \|\| Polarized capacitor \|\|~~
	\|-
	~~\| C2 \|\| 100nF \|\| Device:C \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Unpolarized capacitor \|\|~~
	\|-
	~~\| C3 \|\| 330nF \|\| Device:CP \|\| Capacitor_THT:CP_Radial_D5.0mm_P2.50mm \|\| Polarized capacitor \|\|~~
	\|-
	~~\| C4 \|\| 100nF \|\| Device:C \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Unpolarized capacitor \|\|~~
	\|-
	~~\| C5 \|\| 10nF \|\| Device:C \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Unpolarized capacitor \|\|~~
	\|-
	~~\| C6 \|\| 1nF \|\| Device:C \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Unpolarized capacitor \|\|~~
	\|-
	~~\| C7 \|\| 10uF \|\| Device:CP \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Polarized capacitor \|\|~~
	\|-
	~~\| C8 \|\| 100nF \|\| Device:C \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Unpolarized capacitor \|\|~~
	\|-
	~~\| C9 \|\| 10nF \|\| Device:C \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Unpolarized capacitor \|\|~~
	\|-
	~~\| C10 \|\| 1nF \|\| Device:C \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Unpolarized capacitor \|\|~~
	\|-
	~~\| C11 \|\| 10nF \|\| Device:C \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Unpolarized capacitor \|\|~~
	\|-
	~~\| C12 \|\| 1nF \|\| Device:C \|\| Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm \|\| Unpolarized capacitor \|\|~~
	\|-
	~~\| D1 \|\| IRL81A \|\| Device:LED \|\| LED_THT:LED_SideEmitter_Rectangular_W4.5mm_H1.6mm \|\| Light emitting diode \|\|~~
	\|-
	~~\| D2 \|\| IRL81A \|\| Device:LED \|\| LED_THT:LED_SideEmitter_Rectangular_W4.5mm_H1.6mm \|\| Light emitting diode \|\|~~
	\|-
	~~\| J1 \|\| Jack-DC \|\| Connector:Jack-DC \|\| Connector_BarrelJack:BarrelJack_Wuerth_6941xx301002 \|\| DC Barrel Jack \|\|~~
	\|-
	~~\| J2 \|\| Raspberry_Pi_2_3 \|\| Connector:Raspberry_Pi_2_3 \|\| Connector_PinSocket_2.54mm:PinSocket_2x20_P2.54mm_Vertical \|\| expansion header for Raspberry Pi 2 & 3 \|\|~~
	\|-
	\| J3 \|\| Conn_02x13_Odd_Even \|\| Connector_Generic:Conn_02x13_Odd_Even \|\| Connector_PinHeader_2.54mm:PinHeader_2x13_P2.54mm_Vertical \|\| Generic connector, double row, 02x13, odd/even pin numbering scheme (row 1 odd numbers, row 2 even numbers), script generated (kicad-library-utils/schlib/autogen/connector/) \|\|
	\|-
	\| J4 \|\| RTC \|\| Connector_Generic:Conn_01x05 \|\| Connector_PinHeader_2.54mm:PinHeader_1x05_P2.54mm_Vertical \|\| Generic connector, single row, 01x05, script generated (kicad-library-utils/schlib/autogen/connector/) \|\|
	\|-
	\| J5 \|\| TMP \|\| Connector_Generic:Conn_01x04 \|\| Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical \|\| Generic connector, single row, 01x04, script generated (kicad-library-utils/schlib/autogen/connector/) \|\|
	\|-
	~~\| M1 \|\| 12V Pump \|\| Motor:Fan_CPU_4pin \|\| Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical \|\| CPU Fan, tacho output, PWM input, 4-pin connector \|\|~~
	\|-
	~~\| M2 \|\| AirflowMeter \|\| Motor:Fan_Tacho_PWM \|\| Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical \|\| Fan, tacho output, PWM input, 4-pin connector \|\|~~
	\|-
	~~\| Q1 \|\| LPT80A \|\| Sensor_Optical:LPT80A \|\| OptoDevice:Osram_LPT80A \|\| NPN phototransistor \|\|~~
	\|-
	~~\| Q2 \|\| MMBT3904 \|\| Transistor_BJT:MMBT3904 \|\| Package_TO_SOT_SMD:SOT-23 \|\| 0.2A Ic, 40V Vce, Small Signal NPN Transistor, SOT-23 \|\|~~
	\|-
	~~\| Q3 \|\| LPT80A \|\| Sensor_Optical:LPT80A \|\| OptoDevice:Osram_LPT80A \|\| NPN phototransistor \|\|~~
	\|-
	~~\| R1 \|\| 2k2 \|\| Device:R \|\| Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal \|\| Resistor \|\|~~
	\|-
	~~\| R2 \|\| 100 \|\| Device:R \|\| Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal \|\| Resistor \|\|~~
	\|-
	~~\| R3 \|\| 2k2 \|\| Device:R \|\| Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal \|\| Resistor \|\|~~
	\|-
	~~\| R4 \|\| 10k \|\| Device:R \|\| Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal \|\| Resistor \|\|~~
	\|-
	~~\| RV1 \|\| R_POT \|\| Device:R_POT \|\| Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical \|\| Potentiometer \|\|~~
	\|-
	~~\| SW1 \|\| Interrupt \|\| Switch:SW_Push_Open \|\| Connector_PinHeader_2.54mm:PinHeader_2x01_P2.54mm_Vertical \|\| Push button switch, push-to-open, generic, two pins \|\|~~
	\|-
	~~\| U1 \|\| L7809 \|\| Regulator_Linear:L7809 \|\| Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical \|\| Positive 1.5A 35V Linear Regulator, Fixed Output 9V, TO-220/TO-263/TO-252 \|\|~~
	\|-
	~~\| U2 \|\| L7805 \|\| Regulator_Linear:L7805 \|\| Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical \|\| Positive 1.5A 35V Linear Regulator, Fixed Output 5V, TO-220/TO-263/TO-252 \|\|~~
	\|-
	~~\| U3 \|\| MCP3426-xMS \|\| Analog_ADC:MCP3426-xMS \|\| Package_SO:MSOP-8_3x3mm_P0.65mm \|\| 16-Bit, Multi-Channel ŒîŒ£ Analog-to-Digital Converter with I2C Interface and On-Board Reference, MSOP-8 \|\|~~
	\|}

	~~== Walkthrough 12V general purpose PCB ==~~
	~~<vimeo>568114940</vimeo> Time lapse of assembly~~

	~~'''This guide is for the general purpose 12V PCB which was designed for simplicity so as little as possible SMD components and parts with large footprints are used. '''~~

	<br><br>		<br><br>

Bcmwiki at 18:43, 10 May 2022

2022-05-10T18:43:12Z

← Older revision		Revision as of 20:43, 10 May 2022
Line 13:		Line 13:

	== Component locations 5V bcMeter PCB ==		== Component locations 5V bcMeter PCB ==

			<vimeo>684373327</vimeo> Introduction to bcMeter 5V


	{\| class="wikitable collapsible collapsed sortable"		{\| class="wikitable collapsible collapsed sortable"

Bcmwiki at 18:29, 10 May 2022

2022-05-10T18:29:49Z

Show changes

Assembly - Revision history

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

Bcmwiki at 19:33, 13 October 2024

Bcmwiki at 19:33, 13 October 2024

Bcmwiki: Replaced content with "__FORCETOC__ {{#ev: vimeo | 684373327 | 1000px }} == Overview of parts == '''Requirements: # Screwdriver # Solder Iron # Solder # Flux # 3D Printer / 3d printin..."

Bcmwiki at 19:24, 13 October 2024

Bcmwiki at 19:22, 13 October 2024

Bcmwiki: /* Overview of parts */

Bcmwiki at 19:10, 13 October 2024

Bcmwiki at 18:43, 10 May 2022

Bcmwiki at 18:29, 10 May 2022

Bcmwiki: Replaced content with "FORCETOC {{#ev: vimeo | 684373327 | 1000px }} == Overview of parts == '''Requirements: # Screwdriver # Solder Iron # Solder # Flux # 3D Printer / 3d printin..."