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Daftar Isi

Lembar Persetujuan ............................................................................................ i

Lembar Pengesahan............................................................................................. ii

Pernyataan Keaslian Skripsi ............................................................................... iii

Daftar Isi ............................................................................................................... iv

Daftar Gambar .................................................................................................... vi

Daftar Tabel ......................................................................................................... vii

Daftar Lampiran ................................................................................................. viii

Daftar Simbol ...................................................................................................... ix

I. PENDAHULUAN1.1. Latar Belakang ................................................................................................... 1

1.2. Rumusan Masalah ............................................................................................. 2

1.3. Tujuan ............................................................................................................... 3

1.4. Manfaat ............................................................................................................. 3

1.5. Batasan Masalah ............................................................................................... 3

II. TINJUAN PUSTAKA2.1. Kebutuhan Air Tanaman .................................................................................... 5

2.2. Energi Air Tanah................................................................................................ 62.2.1. Pengertan Energi Air Tanah...................................................................... 62.2.2. Satuan ........................................................................................................ 92.2.3. Tekstur Tanah............................................................................................ 102.2.4. Struktur Tanah........................................................................................... 112.2.5. Pengukuran Kadar Air Tanah dan Energi Air Tanah ................................ 112.2.6. Kurva Karakteristik Tanah ........................................................................ 13

2.3. Rancang Bangun Alat Penyiram Otomatis ........................................................ 142.4.1. Tranducer .................................................................................................. 142.4.2. Pengubah Analog ke Digital ..................................................................... 162.4.3. Mikrokontroller AT 89S51 ....................................................................... 172.4.4. LCD ........................................................................................................... 202.4.5. Relay.......................................................................................................... 23

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2.4.6. Bahasa Assembler ..................................................................................... 23

III. METODE PENELITIAN3.1. Waktu dan Tempat ............................................................................................ 25

3.2. Alat dan Bahan ................................................................................................... 253.2.1 Alat ............................................................................................................. 253.2.2 Bahan ......................................................................................................... 25

3.3. Rancangan Alat .................................................................................................. 263.3.1. Rancangan Fungsional .............................................................................. 263.3.2. Rancangan Struktur ................................................................................... 29

3.4. Analisa Teknik ................................................................................................... 30

3.5. Tanah Sebagai media yang diukur ..................................................................... 33

3.6. Cara Kerja Alat .................................................................................................. 34

3.7 Pelaksanaan Penelitian ........................................................................................ 363.7.1 Perancangan Alat ....................................................................................... 363.7.2 Pengujian Alat dan Pengkalibrasian Alat................................................... 39

IV. HASIL DAN PEMBAHASAN4.1. Perancangan Alat ............................................................................................... 41

4.2. Pengujian dan Pengkalibrasian Alat................................................................... 59

V. PENUTUP5.1. Kesimpulan ........................................................................................................ 70

5.2. Saran................................................................................................................... 73

Daftar Pustaka

Lampiran

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Daftar Gambar

Gambar 1. Pengaturan internal tentang electroda silindris didalam gypsum block menunjukkan electroda yang terpusat (kanan) dan elektroda kawat yang paralel (kiri)............................................................................................. 15

Gambar 2. Diagram Blok dari Suatu Pengubah A/D 4-bit........................................ 17

Gambar 3. Diagram pin dari ADC0804 3-bit pengubah A/D IC .............................. 17

Gambar 4. Diagram mikrokontroler AT89S51 ......................................................... 19

Gambar 5. Gambar Fisik Mikrokontroller AT89S51................................................ 20

Gambar 6. Jenis-jenis Relay ...................................................................................... 23

Gambar 7. Blok diagram rancangan alat penyiram otomatis .................................... 27

Gambar 8. Diagram alir program perangkat lunak .................................................. 29

Gambar 9. Grafik Hubungan Kadar Air Tanah dan nilai pF..................................... 33

Gambar 10. Diagram Alir Perancangan Alat ............................................................ 36

Gambar 11. Blok Diagram Pengujian dan pengkalibrasian Alat .............................. 37

Gambar 12. Diagram Alir Pengujian Sensor............................................................. 38

Gambar 13. Diagram Alir Pengujian Alat................................................................. 40

Gambar 14. Gambar rangkaian sensor ...................................................................... 42

Gambar 15. Diagram alir program awal ................................................................... 47

Gambar 16. Diagram alir program delay .................................................................. 48

Gambar 17. Diagram alir program kalibrasi ............................................................. 48

Gambar 18. Diagram alir program setting batas ....................................................... 49

Gambar 19. Diagram alir program banding data ...................................................... 50

Gambar 20. Gambar layout PCB rangkaian split driver, rangkaian MK,ADC,Driver relay, dan rangkaian catudaya ................................................................. 57

Gambar 21. Gambar rangkaian pengujian sensor dan pengkalibrasian .................... 63

Gambar 22. Grafik hubungan nilai ADC dan hasil pengukuran Kadar Air (%) ...... 64

Gambar 23. Grafik hubungan nilai pF dan Kadar Air (%) ...................................... 65

Gambar 24. Gambar rangkaian pengujian alat.......................................................... 68

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Daftar Tabel

Tabel 1. Kadar Air Tanah dan nilai pF ..................................................................... 34

Tabel 2. Hasil pengukuran kadar air (%) dan nilai ADC pada sensor ...................... 63

Tabel 3. Hasil pengukuran kadar air (%) dan nilai pF .............................................. 65

Tabel 4. Data hasil pengujian pF gypsum dan Kadar Air (%) .................................. 67

Tabel 5. Data kesalahan antara pF sandbox dan pF gypsum .................................... 67

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Daftar Lampiran

Lampiran I. Rangkaian Rencana Penelitian ........................................................ 73

Lampiran II. Rangkaian ADC, LCD, MK AT89S51, keypad, Catu daya, driver

relay, dan relay .................................................................................. 74

Lampiran III. Rangkaian Split Driver dan sensor gypsum block .......................... 75

Lampiran IV. Jadwal Kegiatan Penelitian ............................................................ 76

Lampiran V. Anggaran Biaya Penelitian ............................................................. 77

Lampiran VI. Data hasil Mapping untuk keluaran nilai pF pada LCD .......................... 78

Lampiran VII. Gambar Dokumentasi Penelitian .............................................................. 79

Lampiran VIII. Laporan hasil Analisa Laboratorium ........................................................ 80

Lampiran IX. Data Sheet Komponen ............................................................................. 81

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