Understanding the SDS011 particle sensor - Revision history

Cmpxchg: /* Understanding the SDS011 particle sensor */

2020-03-09T09:43:55Z

Understanding the SDS011 particle sensor

@@ Line 4: / Line 4: @@
 The SDS011 is extensively used for citizen science projects when air quality is in doubt.
-The SDS011 is also the preferred sensor in most citizen science campaigns of governmental initiatives in Germany, The Netherlands and Belgium. For example in the monitoring campaign “de Schone Luchten”, the SDS011 plays a central role in gathering date for the public dialogue about dust exhaust of a local steel mill. Within the scientific community as in the groups of concerning citizens there is a growing concern about the the scientific significance of the data collected by the  SDS011.
+The SDS011 is also the preferred sensor in most citizen science campaigns of governmental initiatives in Germany, The Netherlands and Belgium. For example in the monitoring campaign “de Schone Luchten” [TODO link], the SDS011 plays a central role in gathering date for the public dialogue about dust exhaust of a local steel mill. Within the scientific community as in the groups of concerning citizens there is a growing concern about the the scientific significance of the data collected by the  SDS011. [Citation needed]
 This article is a log of our findings while opening up the sensor and also a description of the process of understand the physics behind the functioning of the device.
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 Ideally we would like to create firmware that comes with a description of what physical properties of the incoming air it can
 measure, and how accurate it could or would be, if all specified pre-conditions are met.
 === Operation of the SDS011 ===
@@ Line 23: / Line 39: @@
 To estimate the scientific value of the data gathered by the SDS011, we think that it is important that the working of the device should be open to the public. Therefore we decided to open up the apparatus and investigate its inner workings.
 === Assumptions made by firmware ===

Cmpxchg at 09:37, 9 March 2020

2020-03-09T09:37:35Z

← Older revision		Revision as of 09:37, 9 March 2020
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	The SDS011 is extensively used for citizen science projects when air quality is in doubt.		The SDS011 is extensively used for citizen science projects when air quality is in doubt.
	The ~~goal~~ of ~~this project is to create~~ a ~~new algorithm~~ for ~~its micro-controller which can be published~~ in the ~~public domain and~~ is ~~therefore open for~~ the ~~scrutiny~~ of ~~others~~.
			The SDS011 is also the preferred sensor in most citizen science campaigns of governmental initiatives in Germany, The Netherlands and Belgium. For example in the monitoring campaign “de Schone Luchten”, the SDS011 plays a central role in gathering date for the public dialogue about dust exhaust of a local steel mill. Within the scientific community as in the groups of concerning citizens there is a growing concern about the the scientific significance of the data collected by the SDS011.

	This article is a log of our findings while opening up the sensor and also a description of the process of understand the physics behind the functioning of the device.		This article is a log of our findings while opening up the sensor and also a description of the process of understand the physics behind the functioning of the device.

			Ideally we would like to create firmware that comes with a description of what physical properties of the incoming air it can
			measure, and how accurate it could or would be, if all specified pre-conditions are met.

	=== Operation of the SDS011 ===		=== Operation of the SDS011 ===
Line 12:		Line 17:
	=== Closed Firmware ===		=== Closed Firmware ===
	Recently a number of scientific articles appeared that try to assess the validity of the SDS011 sensor.		Recently a number of scientific articles appeared that try to assess the validity of the SDS011 sensor.
	However, little is published about the exact physical inner workings of the device, nor on its pre-programmed firmware. Until now researchers take the functioning of the device as a black box. Its firmware is considered corporate property and therefore cannot be tinkered with.		[TODO link them]
			However, little is published about the exact physical inner workings of the device, nor on its pre-programmed firmware.
	The SDS011 is also the preferred sensor in most citizen science campaigns of governmental initiatives in Germany, The Netherlands and Belgium. For example in the monitoring campaign “de Schone Luchten”, the SDS011 plays a central role in gathering date for the public dialogue about dust exhaust of a local steel mill. Within the scientific community as in the groups of concerning citizens there is a growing concern about the the scientific significance of the data collected by the SDS011.		[TODO describe which parts are described]
			Until now researchers take the functioning of the device as a black box. Its firmware is considered corporate property and therefore cannot be tinkered with.

	To estimate the scientific value of the data gathered by the SDS011, we think that it is important that the working of the device should be open to the public. Therefore we decided to open up the apparatus and investigate its inner workings.		To estimate the scientific value of the data gathered by the SDS011, we think that it is important that the working of the device should be open to the public. Therefore we decided to open up the apparatus and investigate its inner workings.
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	=== The board ===		=== The board ===
	[[File:Optical Chambre SDS011, photo Cmpxchg.jpg\|thumb\|Part optical chambre~~, photo Cmpxchg~~]]		[[File:Optical Chambre SDS011, photo Cmpxchg.jpg\|thumb\|Part optical chambre]]
	To do:		To do:
	# Determine the GPO and GPI of the STM32 while processing		# Determine the GPO and GPI of the STM32 while processing
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	=== Re-flashing the STM32 ===		=== Re-flashing the STM32 ===
	[[File:Cut off pins, photo cmpxchg.jpg\|thumb\|Pins cut off~~, photo Cmpxchg~~]]		[[File:Cut off pins, photo cmpxchg.jpg\|thumb\|Pins cut off]]

	A complication for re-programming the STM32 is that the programming pins (SWD) are cut off in the manufacturing process, see photo.		A complication for re-programming the STM32 is that the programming pins (SWD) are cut off in the manufacturing process, see photo.
Line 57:		Line 63:

	=== Develop "bare-metal" drivers ===		=== Develop "bare-metal" drivers ===
	[[File:Connection SDS011, photo Cmpxchg.jpg\|thumb\|Connections~~, photo Cmpxchg~~]]		[[File:Connection SDS011, photo Cmpxchg.jpg\|thumb\|Connections]]
	Create bare-metal drivers for:		Create bare-metal drivers for:
	# Blink a led, visual debugging		# Blink a led, visual debugging
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	== Sources and references ==		== Sources and references ==
	=== Microcontroller stm32f031k6 ===		=== Microcontroller stm32f031k6 ===
	[[File:STM32 f031k6.jpg\|thumb\|F031K6~~, photo Cmpxchg~~]]		[[File:STM32 f031k6.jpg\|thumb\|F031K6]]
	[[Stm32_F031k6_Reference\|Stm32 f031k6 reference page]]		[[Stm32_F031k6_Reference\|Stm32 f031k6 reference page]]

Cmpxchg: /* Understanding the SDS011 particle sensor */

2020-03-09T09:04:33Z

Understanding the SDS011 particle sensor

← Older revision		Revision as of 09:04, 9 March 2020
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	== Understanding the SDS011 particle sensor ==		== Understanding the SDS011 particle sensor ==

	~~On March 3rd, Cmpxchg and Oberoid placed the infamous SDS011 particle sensor on the dissection table at Revspace.~~
	The SDS011 is extensively used for citizen science projects when air quality is in doubt.		The SDS011 is extensively used for citizen science projects when air quality is in doubt.
			The goal of this project is to create a new algorithm for its micro-controller which can be published in the public domain and is therefore open for the scrutiny of others.
	~~Our~~ goal is to create a new algorithm for its micro-controller which can be published in the public domain and is therefore open for the scrutiny of others.
	This article is a log of our findings while opening up the sensor and also a description of the process of understand the physics behind the functioning of the device.		This article is a log of our findings while opening up the sensor and also a description of the process of understand the physics behind the functioning of the device.

Line 14:		Line 12:
	=== Closed Firmware ===		=== Closed Firmware ===
	Recently a number of scientific articles appeared that try to assess the validity of the SDS011 sensor.		Recently a number of scientific articles appeared that try to assess the validity of the SDS011 sensor.
	However, little is published about the exact physical inner workings of the device, nor on its pre-programmed firmware. Until now researchers take the functioning of the device as a black box. Its firmware is considered ~~corperate~~ property and therefore cannot be tinkered with.		However, little is published about the exact physical inner workings of the device, nor on its pre-programmed firmware. Until now researchers take the functioning of the device as a black box. Its firmware is considered corporate property and therefore cannot be tinkered with.

	The SDS011 is also the preferred sensor in most citizen science campaigns of governmental initiatives in Germany, The Netherlands and Belgium. For example in the monitoring campaign “de Schone Luchten”, the SDS011 plays a central role in gathering date for the public dialogue about dust exhaust of a local steel mill. Within the scientific community as in the groups of concerning citizens there is a growing concern about the the scientific significance of the data collected by the SDS011.		The SDS011 is also the preferred sensor in most citizen science campaigns of governmental initiatives in Germany, The Netherlands and Belgium. For example in the monitoring campaign “de Schone Luchten”, the SDS011 plays a central role in gathering date for the public dialogue about dust exhaust of a local steel mill. Within the scientific community as in the groups of concerning citizens there is a growing concern about the the scientific significance of the data collected by the SDS011.
Line 20:		Line 18:
	To estimate the scientific value of the data gathered by the SDS011, we think that it is important that the working of the device should be open to the public. Therefore we decided to open up the apparatus and investigate its inner workings.		To estimate the scientific value of the data gathered by the SDS011, we think that it is important that the working of the device should be open to the public. Therefore we decided to open up the apparatus and investigate its inner workings.

	The goal of this project is to not to crack the corporate code of the SDS011, but instead to reprogram its micro-controller with a new algorithm that forms the basis for future development of particle sensors in the public domain.		=== Definitions ===

			PM1

			PM2.5

			PM10

	People that are interested in this project can visit the RevSpace Hackerspace, which is accessible every day, whenever a participant is present. There may or may not be someone who can tell you something about this project.		=== Assumptions made by firmware ===

	== Reverse engineering ==		== Reverse engineering ==

Juerd: /* Closed Firmware */

2020-03-09T02:56:10Z

Closed Firmware

← Older revision		Revision as of 02:56, 9 March 2020
Line 22:		Line 22:
	The goal of this project is to not to crack the corporate code of the SDS011, but instead to reprogram its micro-controller with a new algorithm that forms the basis for future development of particle sensors in the public domain.		The goal of this project is to not to crack the corporate code of the SDS011, but instead to reprogram its micro-controller with a new algorithm that forms the basis for future development of particle sensors in the public domain.

	People that are interested in this project can visit the RevSpace Hackerspace, which is accessible every ~~Tuesday on the social night~~.		People that are interested in this project can visit the RevSpace Hackerspace, which is accessible every day, whenever a participant is present. There may or may not be someone who can tell you something about this project.

	== Reverse engineering ==		== Reverse engineering ==

Oberoid: /* Microcontroller stm32f031k6 */

2020-03-07T23:09:28Z

Microcontroller stm32f031k6

← Older revision		Revision as of 23:09, 7 March 2020
Line 78:		Line 78:
	=== Microcontroller stm32f031k6 ===		=== Microcontroller stm32f031k6 ===
	[[File:STM32 f031k6.jpg\|thumb\|F031K6, photo Cmpxchg]]		[[File:STM32 f031k6.jpg\|thumb\|F031K6, photo Cmpxchg]]
	[~~https://www.st.com/content/st_com/en/products/microcontrollers-microprocessors/stm32-32-bit-arm-cortex-mcus/stm32-mainstream-mcus/stm32f0-series/stm32f0x1/stm32f031k6.html Datasheet smt32f031k6~~]		[[Stm32_F031k6_Reference\|Stm32 f031k6 reference page]]

Oberoid: /* Re-flashing the STM32 */

2020-03-07T23:06:27Z

Re-flashing the STM32

← Older revision		Revision as of 23:06, 7 March 2020
Line 44:		Line 44:

	=== Re-flashing the STM32 ===		=== Re-flashing the STM32 ===
	[[File:Cut off pins, photo cmpxchg.jpg\|thumb\|cut ~~of pins~~, photo Cmpxchg]]		[[File:Cut off pins, photo cmpxchg.jpg\|thumb\|Pins cut off, photo Cmpxchg]]

	A complication for re-programming the STM32 is that the programming pins (SWD) are cut off in the manufacturing process, see photo.		A complication for re-programming the STM32 is that the programming pins (SWD) are cut off in the manufacturing process, see photo.

Oberoid: /* The board */

2020-03-07T21:25:04Z

The board

← Older revision		Revision as of 21:25, 7 March 2020
Line 29:		Line 29:

	=== The board ===		=== The board ===
	[[File:Optical Chambre SDS011, photo Cmpxchg.jpg\|thumb\|~~Optical Chambre~~, photo Cmpxchg]]		[[File:Optical Chambre SDS011, photo Cmpxchg.jpg\|thumb\|Part optical chambre, photo Cmpxchg]]
	To do:		To do:
	# Determine the GPO and GPI of the STM32 while processing		# Determine the GPO and GPI of the STM32 while processing

Oberoid: /* Re-flashing the STM32 */

2020-03-07T21:22:18Z

Re-flashing the STM32

← Older revision		Revision as of 21:22, 7 March 2020
Line 44:		Line 44:

	=== Re-flashing the STM32 ===		=== Re-flashing the STM32 ===
	[[File:Cut off pins, photo cmpxchg.jpg\|thumb\|cut of pins]]		[[File:Cut off pins, photo cmpxchg.jpg\|thumb\|cut of pins, photo Cmpxchg]]

	A complication for re-programming the STM32 is that the programming pins (SWD) are cut off in the manufacturing process, see photo.		A complication for re-programming the STM32 is that the programming pins (SWD) are cut off in the manufacturing process, see photo.

Oberoid: /* Closed Firmware */

2020-03-07T20:55:48Z

Closed Firmware

← Older revision		Revision as of 20:55, 7 March 2020
Line 14:		Line 14:
	=== Closed Firmware ===		=== Closed Firmware ===
	Recently a number of scientific articles appeared that try to assess the validity of the SDS011 sensor.		Recently a number of scientific articles appeared that try to assess the validity of the SDS011 sensor.
	However, little is published about the exact physical inner workings of the device, nor on its pre-programmed firmware. Until now researchers take the functioning of the device as a black box~~, its~~ firmware is considered corperate property and therefore cannot be tinkered with.		However, little is published about the exact physical inner workings of the device, nor on its pre-programmed firmware. Until now researchers take the functioning of the device as a black box. Its firmware is considered corperate property and therefore cannot be tinkered with.

	The SDS011 is also the preferred sensor in most citizen science campaigns of governmental initiatives in Germany, The Netherlands and Belgium. For example in the monitoring campaign “de Schone Luchten”, the SDS011 plays a central role in gathering date for the public dialogue about dust exhaust of a local steel mill. Within the scientific community as in the groups of concerning citizens there is a growing concern about the the scientific significance of the data collected by the SDS011.		The SDS011 is also the preferred sensor in most citizen science campaigns of governmental initiatives in Germany, The Netherlands and Belgium. For example in the monitoring campaign “de Schone Luchten”, the SDS011 plays a central role in gathering date for the public dialogue about dust exhaust of a local steel mill. Within the scientific community as in the groups of concerning citizens there is a growing concern about the the scientific significance of the data collected by the SDS011.
Line 22:		Line 22:
	The goal of this project is to not to crack the corporate code of the SDS011, but instead to reprogram its micro-controller with a new algorithm that forms the basis for future development of particle sensors in the public domain.		The goal of this project is to not to crack the corporate code of the SDS011, but instead to reprogram its micro-controller with a new algorithm that forms the basis for future development of particle sensors in the public domain.

	People that are interested in this project can visit the RevSpace Hackerspace, which is accessible every ~~tuesday~~ on the social night.		People that are interested in this project can visit the RevSpace Hackerspace, which is accessible every Tuesday on the social night.

	== Reverse engineering ==		== Reverse engineering ==

Oberoid: /* The board */

2020-03-07T20:54:01Z

The board

← Older revision		Revision as of 20:54, 7 March 2020
Line 29:		Line 29:

	=== The board ===		=== The board ===
			[[File:Optical Chambre SDS011, photo Cmpxchg.jpg\|thumb\|Optical Chambre, photo Cmpxchg]]
	To do:		To do:
	# Determine the GPO and GPI of the STM32 while processing		# Determine the GPO and GPI of the STM32 while processing
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	# Create a matching circuit, filtering and gain of the instrumentation amplifier analyzed.		# Create a matching circuit, filtering and gain of the instrumentation amplifier analyzed.

	~~[[File:Optical Chambre SDS011, photo Cmpxchg.jpg\|thumb\|Optical Chambre, photo Cmpxchg]]~~
	=== The sensor ===		=== The sensor ===
	To do:		To do: