DMS load cell with measuring amplifier HX711AD - Versionsgeschichte

Onyesi-john.abiagam@stud.hshl.de: /* Summary */

2026-06-09T06:57:34Z

Summary

← Nächstältere Version		Version vom 9. Juni 2026, 06:57 Uhr
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	In this project, a digital weighing system using a DMS load cell and the HX711AD measuring amplifier was successfully implemented. The system was first developed using Arduino, including sensor reading, calibration, filtering, tare functionality, LCD output, and buzzer feedback.		In this project, a digital weighing system using a DMS load cell and the HX711AD measuring amplifier was successfully implemented. The system was first developed using Arduino, including sensor reading, calibration, filtering, tare functionality, LCD output, and buzzer feedback.

	Afterwards, the same DMS load cell and the HX711AD measuring amplifier was implemented in MATLAB/Simulink. The system was tested with reference weights and achieved stable measurements. For a 397 g reference weight, the measured value was approximately 396.46 g with an average measurement uncertainty of ~~σ ≈~~ 0.012 g.		Afterwards, the same DMS load cell and the HX711AD measuring amplifier was implemented in MATLAB/Simulink. The system was tested with reference weights and achieved stable measurements. For a 397 g reference weight as an example, the measured value was approximately 396.46 g with an average measurement uncertainty of approximately 0.012 g.
	Most of the weighing scales functions were successfully implemented in Simulink; however, the power button functionality could not be implemented due to memory limitations during the Simulink implementation.		Most of the weighing scales functions were successfully implemented in Simulink; however, the power button functionality could not be implemented due to memory limitations during the Simulink implementation.

Onyesi-john.abiagam@stud.hshl.de am 8. Juni 2026 um 21:07 Uhr

2026-06-08T21:07:29Z

← Nächstältere Version		Version vom 8. Juni 2026, 21:07 Uhr
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	\|}		\|}

			= Summary and Outlook =
			===''' Summary ''' ===
			In this project, a digital weighing system using a DMS load cell and the HX711AD measuring amplifier was successfully implemented. The system was first developed using Arduino, including sensor reading, calibration, filtering, tare functionality, LCD output, and buzzer feedback.

			Afterwards, the same DMS load cell and the HX711AD measuring amplifier was implemented in MATLAB/Simulink. The system was tested with reference weights and achieved stable measurements. For a 397 g reference weight, the measured value was approximately 396.46 g with an average measurement uncertainty of σ ≈ 0.012 g.
			Most of the weighing scales functions were successfully implemented in Simulink; however, the power button functionality could not be implemented due to memory limitations during the Simulink implementation.

			==='''Outlook'''===
			Future improvements could focus on increasing measurement accuracy through enhanced filtering and calibration methods.There could be further optimization of the Simulink model.
	= Project Timeline =		= Project Timeline =

Onyesi-john.abiagam@stud.hshl.de am 8. Juni 2026 um 20:35 Uhr

2026-06-08T20:35:01Z

← Nächstältere Version		Version vom 8. Juni 2026, 20:35 Uhr
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	<math>Weight = 396.45\ \text{g} \pm 0.012\ \text{g}</math>		<math>Weight = 396.45\ \text{g} \pm 0.012\ \text{g}</math>

			= Evaluation =

			{\| class="wikitable"
			\|+ style = "text-align: left"\| Table 1: Test report against requirements
			\|-
			! Req. !! Description !! Test result
			\|-
			\| 1 \|\| The mass must be determined using the HX711AD load cell via Arduino and Simulink. \|\| 100%
			\|-
			\| 2 \|\| The measuring range must be determined. \|\| 100%
			\|-
			\| 3 \|\| The measurement uncertainty (1σ) must be determined for the measuring range and displayed as a confidence interval. \|\| 100%
			\|-
			\| 4 \|\| The <code>on/off</code> button starts the system. The sensor must first be calibrated and display 0 g. \|\| 100%
			\|-
			\| 5 \|\| The weight must be referenced for the measuring range. \|\| 100%
			\|-
			\| 6 \|\| The measured values must be filtered/smoothed over time. \|\| 100%
			\|-
			\| 7 \|\| A beep must indicate when the measured value is stable/constant. \|\| 100%
			\|-
			\| 8 \|\| The sensor system must display the weight in g on a display. \|\| 100%
			\|-
			\| 9 \|\| The <code>tara</code> button resets the current weight to 0 g (recalibration). \|\| 100%
			\|}


	= Project Timeline =		= Project Timeline =

Onyesi-john.abiagam@stud.hshl.de: /* Calibration and Tare */

2026-06-08T20:01:22Z

Calibration and Tare

← Nächstältere Version		Version vom 8. Juni 2026, 20:01 Uhr
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	The system was calibrated using a two-point procedure consisting of offset and scale factor determination.		The system was calibrated using a two-point procedure consisting of offset and scale factor determination.

	* Offset was obtained as the average of raw readings with no load applied.		* '''Offset''' was obtained as the average of raw readings with no load applied.
	* Scale factor was determined using a known reference mass to convert raw ADC values into grams.		* '''Scale factor''' was determined using a known reference mass to convert raw ADC values into grams.
	The calibration was applied directly within the processing chain to produce real-time weight measurements.		The calibration was applied directly within the processing chain to produce real-time weight measurements.

Onyesi-john.abiagam@stud.hshl.de: /* Simulink */

2026-06-08T19:59:04Z

Simulink

← Nächstältere Version		Version vom 8. Juni 2026, 19:59 Uhr
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	Model Overview		Model Overview

	* HX711 Read Block (custom block using IO Device Builder) – reads the 24-bit value via DOUT (Digital Pin 10) and PD_SCK (Digital Pin 9).		* '''HX711 Read Block''' (custom block using IO Device Builder) – reads the 24-bit value via DOUT (Digital Pin 10) and PD_SCK (Digital Pin 9).
	* Calibration & Scaling – subtracts offset and multiplies by scale factor.		* '''Calibration & Scaling''' – subtracts offset and multiplies by scale factor.
	* Digital Filter – first-order recursive (IIR) low-pass filter with smoothing factor α = 0.1, used to reduce measurement noise.		* '''Digital Filter'''– first-order recursive (IIR) low-pass filter with smoothing factor α = 0.1, used to reduce measurement noise.
	* Stability Detection – ~~moving~~ standard deviation computed over ~~a sliding window of~~ recent samples; the ~~window~~ size is adjustable and was tuned experimentally.		* '''Stability Detection''' – standard deviation computed over recent samples from the low pass filter; the sample size is adjustable and was tuned experimentally.
	* Display – filtered weight on a Scope and/or LCD (custom block using IO Device Builder).		* '''LCD Display''' – filtered weight on a Scope and/or LCD (custom block using IO Device Builder).
	* Button Inputs – external interrupt-based inputs (using Arduino Support Package for Simulink) for the power button (Interrupt Pin 3) and tare button (Interrupt Pin 2), enabling immediate event-driven response.		* '''Button Inputs''' – external interrupt-based inputs (using Arduino Support Package for Simulink) for the power button (Interrupt Pin 3) and tare button (Interrupt Pin 2), enabling immediate event-driven response.

	Note: The Simulink Arduino support package does not natively support the HX711 and LCD; custom blocks were created using the IO Device Builder.		Note: The Simulink Arduino support package does not natively support the HX711 and LCD; custom blocks were created using the IO Device Builder.


	= Measurement =		= Measurement =

Onyesi-john.abiagam@stud.hshl.de: /* Requirements */

2026-06-08T17:36:58Z

Requirements

← Nächstältere Version		Version vom 8. Juni 2026, 17:36 Uhr
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	\|+ style = "text-align: left"\| Table 1: Requirements for the Unit		\|+ style = "text-align: left"\| Table 1: Requirements for the Unit
	\|-		\|-
	! Req. !! Description !! Priority ~~!! Progress~~		! Req. !! Description !! Priority
	\|-		\|-
	\| 1 \|\| The mass must be determined using the HX711AD load cell via Arduino and Simulink. \|\| 1 ~~\|\| 100%~~		\| 1 \|\| The mass must be determined using the HX711AD load cell via Arduino and Simulink. \|\| 1
	\|-		\|-
	\| 2 \|\| The measuring range must be determined. \|\| 1 ~~\|\| 100%~~		\| 2 \|\| The measuring range must be determined. \|\| 1
	\|-		\|-
	\| 3 \|\| The measurement uncertainty (1σ) must be determined for the measuring range and displayed as a confidence interval. \|\| 2 ~~\|\| 100%~~		\| 3 \|\| The measurement uncertainty (1σ) must be determined for the measuring range and displayed as a confidence interval. \|\| 2
	\|-		\|-
	\| 4 \|\| The <code>on/off</code> button starts the system. The sensor must first be calibrated and display 0 g. \|\| 1 ~~\|\| 100%~~		\| 4 \|\| The <code>on/off</code> button starts the system. The sensor must first be calibrated and display 0 g. \|\| 1
	\|-		\|-
	\| 5 \|\| The weight must be referenced for the measuring range. \|\| 1 ~~\|\| 100%~~		\| 5 \|\| The weight must be referenced for the measuring range. \|\| 1
	\|-		\|-
	\| 6 \|\| The measured values must be filtered/smoothed over time. \|\| 1 \|\| ~~100%~~		\| 6 \|\| The measured values must be filtered/smoothed over time. \|\| 1
	\|-		\|-
	\| 7 \|\| A beep must indicate when the measured value is stable/constant. \|\| 1 ~~\|\| 100%~~		\| 7 \|\| A beep must indicate when the measured value is stable/constant. \|\| 1
	\|-		\|-
	\| 8 \|\| The sensor system must display the weight in g on a display. \|\| 1 \|\| ~~100%~~		\| 8 \|\| The sensor system must display the weight in g on a display. \|\| 1
	\|-		\|-
	\| 9 \|\| The <code>tara</code> button resets the current weight to 0 g (recalibration). \|\| 1 ~~\|\| 100%~~		\| 9 \|\| The <code>tara</code> button resets the current weight to 0 g (recalibration). \|\| 1
	\|}		\|}

Onyesi-john.abiagam@stud.hshl.de: /* Requirements */

2026-06-08T17:06:08Z

Requirements

← Nächstältere Version		Version vom 8. Juni 2026, 17:06 Uhr
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	! Req. !! Description !! Priority !! Progress		! Req. !! Description !! Priority !! Progress
	\|-		\|-
	\| 1 \|\| The mass must be determined using the HX711AD load cell via Arduino and Simulink. \|\| 1 \|\| ~~Done~~		\| 1 \|\| The mass must be determined using the HX711AD load cell via Arduino and Simulink. \|\| 1 \|\| 100%
	\|-		\|-
	\| 2 \|\| The measuring range must be determined. \|\| 1 \|\| ~~Done~~		\| 2 \|\| The measuring range must be determined. \|\| 1 \|\| 100%
	\|-		\|-
	\| 3 \|\| The measurement uncertainty (1σ) must be determined for the measuring range and displayed as a confidence interval. \|\| 2 \|\| ~~Done~~		\| 3 \|\| The measurement uncertainty (1σ) must be determined for the measuring range and displayed as a confidence interval. \|\| 2 \|\| 100%
	\|-		\|-
	\| 4 \|\| The <code>on/off</code> button starts the system. The sensor must first be calibrated and display 0 g. \|\| 1 \|\| ~~Done~~		\| 4 \|\| The <code>on/off</code> button starts the system. The sensor must first be calibrated and display 0 g. \|\| 1 \|\| 100%
	\|-		\|-
	\| 5 \|\| The weight must be referenced for the measuring range. \|\| 1 \|\| ~~Done~~		\| 5 \|\| The weight must be referenced for the measuring range. \|\| 1 \|\| 100%
	\|-		\|-
	\| 6 \|\| The measured values must be filtered/smoothed over time. \|\| 1 \|\| ~~Done~~		\| 6 \|\| The measured values must be filtered/smoothed over time. \|\| 1 \|\| 100%
	\|-		\|-
	\| 7 \|\| A beep must indicate when the measured value is stable/constant. \|\| 1 \|\| ~~Done~~		\| 7 \|\| A beep must indicate when the measured value is stable/constant. \|\| 1 \|\| 100%
	\|-		\|-
	\| 8 \|\| The sensor system must display the weight in g on a display. \|\| 1 \|\| ~~Done~~		\| 8 \|\| The sensor system must display the weight in g on a display. \|\| 1 \|\| 100%
	\|-		\|-
	\| 9 \|\| The <code>tara</code> button resets the current weight to 0 g (recalibration). \|\| 1 \|\| ~~Done~~		\| 9 \|\| The <code>tara</code> button resets the current weight to 0 g (recalibration). \|\| 1 \|\| 100%
	\|}		\|}

Onyesi-john.abiagam@stud.hshl.de: /* Related Links */

2026-04-23T11:42:27Z

Onyesi-john.abiagam@stud.hshl.de: /* Related Links */

2026-04-23T11:42:01Z

Onyesi-john.abiagam@stud.hshl.de: /* Microcontroller Peripherals */

2026-04-23T11:36:10Z

Microcontroller Peripherals

← Nächstältere Version		Version vom 23. April 2026, 11:36 Uhr
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	\| Buzzer \|\| Acoustic feedback \|\| Digital Output \|\| Indicates stable measurement		\| Buzzer \|\| Acoustic feedback \|\| Digital Output \|\| Indicates stable measurement
	\|-		\|-
	\| Push Button (Power) \|\| System control \|\| Interrupt Pin (~~e.g., D2~~) \|\| Starts or stops the system		\| Push Button (Power) \|\| System control \|\| Interrupt Pin (D3) \|\| Starts or stops the system
	\|-		\|-
	\| Push Button (Tare) \|\| Reset function \|\| Interrupt Pin (~~e.g., D3~~) \|\| Resets measured value to 0 g		\| Push Button (Tare) \|\| Reset function \|\| Interrupt Pin (D2) \|\| Resets measured value to 0 g
	\|}		\|}

← Nächstältere Version		Version vom 23. April 2026, 11:42 Uhr
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	= Related Links =		= Related Links =
	*[https://wolles-elektronikkiste.de/hx711-basierte-waage HX711 based weight scale]		*[https://wolles-elektronikkiste.de/hx711-basierte-waage HX711 based weight scale]
	*[https://wiki.hshl.de/wiki/index.php/~~LCD_Modul_16x02_I²C~~ LCD Modul 16x02 ~~I²C~~ (HSHL Wiki)]		*[https://wiki.hshl.de/wiki/index.php/LCD_Modul_16x02_I2C LCD Modul 16x02 I2C (HSHL Wiki)]
	*[https://learn.sparkfun.com/tutorials/getting-started-with-load-cells Getting Started with Load Cells – SparkFun]		*[https://learn.sparkfun.com/tutorials/getting-started-with-load-cells Getting Started with Load Cells – SparkFun]
	*[https://justdoelectronics.com/load-cell-hx711-module/ Load Cell with HX711 Module – Tutorial]		*[https://justdoelectronics.com/load-cell-hx711-module/ Load Cell with HX711 Module – Tutorial]

← Nächstältere Version		Version vom 23. April 2026, 11:42 Uhr
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	= Related Links =		= Related Links =
	*[https://wolles-elektronikkiste.de/hx711-basierte-waage HX711 based weight scale]		*[https://wolles-elektronikkiste.de/hx711-basierte-waage HX711 based weight scale]
	*[https://wiki.hshl.de/wiki/index.php/~~LCD_Modul_16x02_I2C~~ LCD Modul 16x02 ~~I2C~~ (HSHL Wiki)]		*[https://wiki.hshl.de/wiki/index.php/LCD_Modul_16x02_I²C LCD Modul 16x02 I²C (HSHL Wiki)]
	*[https://learn.sparkfun.com/tutorials/getting-started-with-load-cells Getting Started with Load Cells – SparkFun]		*[https://learn.sparkfun.com/tutorials/getting-started-with-load-cells Getting Started with Load Cells – SparkFun]
	*[https://justdoelectronics.com/load-cell-hx711-module/ Load Cell with HX711 Module – Tutorial]		*[https://justdoelectronics.com/load-cell-hx711-module/ Load Cell with HX711 Module – Tutorial]