Rahmat Awaludin Salam

Potentiometer a simple light dependent resistor-based digital

A digital potentiometer, which can be used to implement automatic calibration procedure in a circuit, to control a switch of a power supply, or as a load tester, was developed by using a light-dependent resistor (LDR) and implementing a proportional controller. It consisted of a light emitting diode (LED) used to change the resistance of LDR, two LDRs set as the output and the feedback of the controller, a keypad to enter the set point, an LCD to present the data and the processes of microcontroller, and an ATmega 8535 microcontroller to manage all processes of the system. Under the trial-error tuning method, it has been obtained that the proportional constant was 500. For the desired resistance ranging from 5 to 10kΩ, its steady-state error was in the range of 20 to 290Ω. In fact, this maximum steady-state error (290Ω) was higher than those obtained from the previous works. However, the developed system was simple and low cost.

Design and implementation of wireless sensor network on Ground movement Detection System

The raise of land usage and human population increase the number of areas which are prone to landslide disaster. Real time monitoring system on these risk areas can minimize the losses caused by it. One physical phenomenon that can be observed from this disaster is ground movements. This paper discusses about the implementation of wireless sensor network for real time ground movement monitoring. The system consists of Inclinometer, GPS, Xbee Pro, SIM900 and a 9 V power supply. To detect the ground movement, the system used inclinometer sensor. The calibration was done using a homemade tilt calibrator. Xbee pro was used as node transmission system with star topology and then SIM900 was used as a transmitter between the coordinator with the server. The system additionally used GPS to show the position of node and to detect the occurrence of landslide at certain area. Code igniter was used to build web server so that the data can be accessed in real time. From the test, it was shown that the system could detect the ground movement and the observation data was sent to the server precisely.

Development of a Wireless Sensor Network for Temperature and Humidity Monitoring

The development of a wireless sensor network system for temperature and humidity monitoring is described. The system is composed of two main parts, namely an end device and a coordinator. The end device consists of an SHT10 sensor, an XBee Pro RF module, an ATMega8535 microcontroller, and a battery. The coordinator consists of an XBee Pro RF module and an SIM900 GSM module. The temperature and humidity data were sent by the end device to the coordinator and they were forwarded to the web server via GPRS communication using the SIM900 GSM module. In order to the data stored in the database can be accessed in real time via the internet, a web server is developed by using CodeIgniter (CI). It was shown that each end device can communicate very well with the coordinator. Moreover, the data are received in accordance with the timing of delivery was given.

A simple and low cost tilt examiner system development for a precise landslide early warning system

Historical data for every disaster provide the information about every single physical phenomenon that can be observed to estimate and monitor the happening of the next disaster event. Some physical parameter that often be investigated are ground movement and changing inclination of the land. Those phenomena are the key points on predicting the occurrence of disaster especially landslide and volcano eruption. One of the method that can be used to prevent the loss of life caused by the disasters is by observing the movement and the change of the slope of inclination at the prone areas using tilt sensor. The increase of possibility of disaster occurrence is reflected on the increase of tilt sensor usage. Therefore, a simple system for testing the performance of a tilt sensor is required. A simple and low cost tilt calibrator has been made by using a stepper motor that is controlled by AVR ATMega8 in which its data and control parameter would be displayed in a 16×2 LCD. The system calibrator was developed to...

Development of a simple low-scale solar simulator and its light distribution

A simple low-scale solar simulator was developed. Three different lamps, which are conventional lightbulb, softone lightbulb, and halogen lamp, were employed as light sources. The halogen lamp, in fact, gave better intensity compared to the other lamps in which its intensity is closer to the field-measured sun intensity. In addition to measuring the light intensity distribution inside the simulator, simulation was also done using the Monte Carlo method. It was found that the Monte Carlo simulation fit very well the experimental data. Moreover, the light was centralized beneath the light source and well distributed inside the chamber. The intensity along the horizontal plane varied according to its position. The developed system can therefore be used for simulating the real sunlight very well.

Web-Based Surface Level Measuring System Employing Ultrasonic Sensors and GSM/GPRS-Based Communication

Water surface level should get special attention as water can cause disasters such as flood when its surface exceeds a certain level. A real time early warning system to monitor water surface level is necessary for avoiding severe effects of flood to human life. A web-based water level measuring system using an ultrasonic sensor can be an alternative choice for developing the early warning system. It is known that the system has advantages in the installation and maintenance compared to other systems. This paper discusses the design of a water level measuring system integrated with an internet web server. Ultrasonic sensors are used to measure the water surface level. A GSM / GPRS-based communication system is applied for sending measured water levels to a web server. The results indicate that the measurement data are in accordance with the water levels manually obtained. The results also show that the system works real time.

Design of Deformation Monitoring System for Volcano Mitigation

Indonesia has many active volcanoes that are potentially disastrous. It needs good mitigation systems to prevent victims and to reduce casualties from potential disaster caused by volcanoes eruption. Therefore, the system to monitor the deformation of volcano was built. This system employed telemetry with the combination of Radio Frequency (RF) communications of XBEE and General Packet Radio Service (GPRS) communication of SIM900. There are two types of modules in this system, first is the coordinator as a parent and second is the node as a child. Each node was connected to coordinator forming a Wireless Sensor Network (WSN) with a star topology and it has an inclinometer based sensor, a Global Positioning System (GPS), and an XBEE module. The coordinator collects data to each node, one a time, to prevent collision data between nodes, save data to SD Card and transmit data to web server via GPRS. Inclinometer was calibrated with self-built in calibrator and tested in high temperature environment to check the durability. The GPS was tested by displaying its position in web server via Google Map Application Protocol Interface (API v.3). It was shown that the coordinator can receive and transmit data from every node to web server very well and the system works well in a high temperature environment.

A Simple Accelerometer Calibrator

High possibility of earthquake could lead to the high number of victims caused by it. It also can cause other hazards such as tsunami, landslide, etc. In that case it requires a system that can examine the earthquake occurrence. Some possible system to detect earthquake is by creating a vibration sensor system using accelerometer. However, the output of the system is usually put in the form of acceleration data. Therefore, a calibrator system for accelerometer to sense the vibration is needed. In this study, a simple accelerometer calibrator has been developed using 12 V DC motor, optocoupler, Liquid Crystal Display (LCD) and AVR 328 microcontroller as controller system. The system uses the Pulse Wave Modulation (PWM) form microcontroller to control the motor rotational speed as response to vibration frequency. The frequency of vibration was read by optocoupler and then those data was used as feedback to the system. The results show that the systems could control the rotational speed and the vibration frequencies in accordance with the defined PWM.

Characterization of a water level measurement system developed using a commercial submersible pressure transducer

A water level measurement system employing a commercial submersible pressure transducer was developed. The submersible pressure transducer consists of a piezoresistive sensor configured in a Wheatstone bridge, a signal conditioner, and a 4–20 mA transmitter. The measurement system is also equipped with a 4–20 mA receiver for long wire transmission and an 8-bit ADC contained in an ATmega 16 microcontroller for further processing and providing water level display. Based on the characterization of the obtained measurement result, a linear correlation between the water level and the sensor output was obtained. It is shown that the pipe diameter and the position of the sensitive part of the sensor do not affect the sensor output. This implies that the change on the sensor output is only due to the level of the water. It was also found that the submersible water level sensor possesses high accuracy, sensitivity, stability, linearity, and proper hysteresis characteristics.

Measurement of Glucose in Blood Using a Simple Non Invasive Method

The amount of glucose in blood of human beings should be controlled. The excess or deficiency in glucose of human blood can cause a variety of diseases such as diabetes, heart disease, cholesterol and blindness. We report the design and development of a simple spectrometer as a non-invasive method to determine glucose in urine. Note that glucose in urine, which is caused by exceeding glucose level from the threshold in the renal system, is correlated with that in blood since glucose is a part of acid hydrate in the digestive tract and is absorbed by the intestine in the blood circulation. Urine containing glucose is reacted with a benedict solution that in turn affects the turbidity of urine according to the glucose concentration in the urine. Urines with various turbidities were then placed in transparent containers sitting between a light emitting diode (LED) as a light source and a photodiode as a detector of the simple spectrometer. As the concentration of glucose in the mixture solution became higher, the mixture solution developed more turbid and the output voltage of the photodiode would then be smaller. Moreover, the color of LED affects the magnitude of light intensity that can be transmitted by the sample.