Masturyono[1], D.T. Heryanto, T. Mulyani, A.T. Damar

Meteorological Climatological and Geophysical Agency (BMKG)

Jl. Angkasa I / No. 2 Kemayoran, Jakarta Pusat

(Telp. +62 21 6545626; Fax. +62 21 6545626 )

e-mail : ;;;;


BMKG has developed a prototype of Automatic Rain Water Sampler GSM System ( ARWS_GSM SYS). This prototype uses the sensor of Tipping Buckets Rain Gauge Sensor with output pulse. The main objective of developing ARWS_GSM SYS is data logger unit that using the ATMEL ATMega-32 Microcontroller as the main component and Synchronous Alternating Current Motor driven units for automatic lid arms controller. For Acquisition purpose, we used Assembler programming and for application software the Visual Basic 6.0 and Excel data sheet programming. Calibration results showsThe Automatic Rain Water SamplerGSMSystem of BMKG Product was designed specifically for taking the rainwater sample and to be analysing at the Laboratory to investigations of rainwater chemical composition and acidity.

This ARWS_GSMSYS equipped with GSM data modem torequest the rainfall data via Handphone.


The main task of Meteorology Climatology and Geophysical is to carry out of the air quality monitoring; one of them are taking the rainwater sample forinvestigations of rainwater chemical composition analysis and acidity. The Automatically Rainwater collector sampler equipments must need it to handle this matter.

This will influence data availability and continuity, and also the analysis result done by BMKG. To overcome this condition BMKG need to design automatic rainfall observation system including of rain water collector sampled to analysis the rain water chemistry compound which done by BMKG air quality laboratory in Jakarta Head office.

This instruments has 2 unit devices :

  1. Tipping buckets sensor or rain-gauge buckets sensor as observation rainfall system and;
  2. Rainwater sample collectors device ( see Figure 1; and Figure 2).

This device designed to operate in automatically rainfall when 0.2 mm (0.01inch) rain water fallen into tipping bucket tip sensors and send the pulse from sensor into data logger counter system to start count and driven motor unitto operate at the same time. This sensor is very sensitive when the rain fall periods happens, The driven motor unit give the command the lid arm ARWS to open automatically, we were known that the first rain fall will be bring amountof acidity elements in the atmosphere whichdissolved intorain water.

After 10 minutes rain water fall were stopped, the driven motor unit given command tolid arm ARWSto close automatically.This matter aims to prevent the rainwater sample not contaminate by pollute which isbrought at dry deposition period.


The Main system of ARWS_GSMSYS is supplied with an RS-232 cable and collection software suitable for use with compatible PC, Lap-Top, Data Flash Card and GSM data modemdevice, complete with rain gauge, data logger, battery, RS-232 cable and Windows data managementsoftware.

The Basic system of ARWS_GSMSYS consists of data acquisition, conversion into computer-readable format, proper processing of the data in accordance with specified algorithms, setup data storage of processed data and their transmission to PC.

The choice of ATMEL microcontroller product is based on the availability at the domestic market. For the future and advanced microcontroller will be chosen, due to the complexity tasks for being performed. The most important this for BMKG is to have an experience in designing, building and operating ARWS by its own technicians.

Figure 3 is a block diagram that shows the design concept of ARWS_GSMSYS. The uses of digital sensor given an advantage cause the complexity of design. Pulse that came from sensor will be multiplied with coefficient factor that determined into logger. Data storage interval in every minute. All of data rainfall be kept to file in SD card. Real Time data also can directshows at computer/laptop, by using the rainfall observation software. Rainfall data can be request into minute, hours, day, week, monthly form; in scrolling data. Also can be downloadingfrom logger internal memory into EXCEL standard sheetvia RS-232 serial port, and can be accessed by Short Messages Service (SMS) viaHand phonewith determined in (minute, hours, week, month) format request.




Figure 4. Data Logger

ACS210 in Figure 4, operated to pass Intel micro-controller 80C31 be technology apparatus CMOS that make possible ACS210 can operate with Ni-Caddry battery during sufficiently long without use power electricity source.

The LCD consist of 16 characters in 2 lines and 16 buttons to putthe command into logger system.

ACS210 also operate as data logger and Real Time Clock (RTC). ACS210 this can to keep rain fall data period (to records date and time when rainfall periodstarts and rainfall period was end).

Data also able to download with notebook computer with facilities of RS-232 connection cable serial port and it shows in scrolling data form.

Figure 5. GSM Data Modem

In Figure 5. The GSM Data Modem,GSM Data Collector device unit with special internal antenna.


Rainfall data can be download by using Data Windows Management software (serial.exe) and entire all of data exist in data logger stored into PC.

Display in PC monitor at the download procedure are shown in Figure 6.


The microcontroller used in the development of ARWS_GSM SYS is manufactured by ATMEL, called ATMega-32. It has a small internal memory and only one processor in the prototype of ARWS_GSM SYS .

In the future, instead of ATMega-32, ATMega-128 is used. The reason is, the latter has features that have much bigger internal memory and more than one processor. To continuing improvement engineering of ARWS_GSM SYS instrument in next product, we will usedthe Remote Control Setup System by using facilities modem and used the CSD programming system.

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[1] Director of Instrumentation, Engineering and CalibrationCenter BMKG-Indonesia