1st case: water level

Hi,

This time we,kelompok kucing beranak 5 will present our task that Mr.Priyatmadi gave us yesterday. Yeah,it is our 1^st task,”How to control water level tank”. The task itself contain 2 cases. The 1^st is controlling water level tank into stable height 1 metre,so if the level reached 1 metre, the source water (ie water tap) stopped; in other word the level maintained constant 1 metre.

The 2^nd case is how if we want to control its level? Off to topic,thanks to indra we had completed this 2^nd case which way more difficult than 1^st cause of his experience in robotic design (yes,INDRA DARMAWAN BUDI teamed with his friends compete for national robotic art festival held not in july,lets pray for their victory ^^),oke back to topic, the idea for 2^nd task is simple. Just do it with microcontroller.

Oke,here it goes my group’s plan about the task given by Mr priyatmadi;

1. Maintained water level into constant 1 metre

Well,to be honest, at first we didn’t knew what should we did -_-. Then Mr priyatmadi came to our group and asked if we had completed the task or not. Hahaha,we honestly said that we hadn’t did anything yet. Then mr.priyatmadi said: “why don’t you use transducer as its core?” Voila,yeah we forgot about transducer. Basicly,transducer is a device that converts one type of energy to another. The conversion can be to/from electrical, electro-mechanical, electromagnetic, photonic, photovoltaic, or any other form of energy. While the term transducer commonly implies use as a sensor/detector, any device which converts energy can be considered a transducer.

From Instrumentation Elektronik class,we had received some transducer lesson,so we decided to use pressure transducer,that is flexiforce. The characteristic of flexi force is a transducer or we should say sensor that convert pressure or weight into resistance. The idea is simple: place flexiforce at the bottom of the tank and then connect its output with adc and then follow with some nice listing in micro (see the file,). Maybe it is easier to understand with step:

1. Collect data

Convert pressure given by water at various level into resistance using flexiforce (just put it in the bottom of the tank). The result later used to code microcontroller

2. Design listing in microcontroller

Our idea is simple,from data that we had collected before,various resistance that produced from flexi converted in adc into random number starting from 0-255. This number is our key to design micro. Simply,use 0 to describe zero level and 255 to 1 metre level.

But from indra’s experience (yeah,indra and his robot’s :p) if we just use exact number (I mean 0 for zero water and 255 for 1 metre) we couldn’t get exact 1 metre level because there were some interference produced from response time from flexiforce –adc-micro-pump. So in micro that we design we determine 0-10 to describe zero level and 250-255 to 1 metre just to make sure that interference didn’t hamper our design. (for complete syntax and program discussed in ppt)

3. -_-

Simply connect flexi force – adc – micro with pump and voila,case 2 is solved ^^

2^nd case :

Well,the 2^nd case is not much different from 1^st case,based on indra’s experience controlling the level is what we wanted,just determine what adc conversion should be made. I mean,in 1^st case we determine that zero level = 0 adc and 1 metre = 255. So if given the maximum height is 2 metre then,just make a complete conversion list of adc, the idea is simple -_-, 0 adc for zero level,255 for max level (2 metre) and from 1 – 254 for other height,such as 10 for 5 cm and 150 for 120 cm. the device that we design is not 100% automatic,for 2^nd case it require operator to turn water tap on or off,basicly,our 2^nd case device is just for reminder of height, if the height is suitable the the operator can turn the water tap off,if it’s not yet suitable just keep it on.

3^rd case:

Well,actually there isn’t 3rd case,its about development of our plan about device that we made,we added some cool feature,that is telemetry. What is telemetry? It is a technology that allows remote measurement and reporting of information. The word is derived from Greek roots tele = remote, and metron = measure. Systems that need external instructions and data to operate require the counterpart of telemetry, telecommand.

Basicly if we added telemetry and telecommand,we could remote water level tank from anywhere and we could control its level from anywhere,pretty cool huh? To allow that first we must get what called API ( application program interface). It is an application that allow communication 2 different devices. In this case we use handphone as an controller for water level tank

Interested? Download full presentation file in here ^^