Applications and Implications


Individual Project


Learning outcomes:


Have you answered the following questions:


What will it do?


On June 6, 2020, I decided to change my final project again!

Project diary update here.

I needed to have irrigation working on the farm. I did not need more chickens right now, so I changed it again. That doesn't mean I gave up on the chicken egg incubator. It only means I might have TWO final projects :-). Well, maybe not. The reality is that I will focus on irrigation; my fruit trees need water, and the greenhouse does too. I have so much need for it right now and I need it to work well, which makes it really worth the change.

So, no chickens! YES, WATER! Maybe also chickens.

To answer it clearly, my final project will be an irrigation system. It will allow me to schedule irrigation events by zone and time and will also present humidity and temperature. The PCB will have extra pins for expansion, and it will be enclosed in a waterproof box.

I made a few sketches:

Initial Sketch In this sketch, I show how the package shape and web interface are going to be.


Who has done what beforehand?


A number of companies sell irrigation controller systems.

On the Alibaba website, we can see many options with an almost infinite price range, as well as capabilities.

Alibaba Irrigation Systems

JOGIN FRANCIS made a really nice automatic valve for irrigation automation that could definitely be added to my project, but for now, I will focus more on the interface and controller and use commercial valves.

João Milheiro also made an irrigation system, which he is using to control the environment of a mushroom growing kit.


What will you design?

I will design the PCB, which will have at its center an ESP32, and relays for the activation of different solenoid valves, a pump, and a sensor.

I will also design the waterproof enclosure as well as a gasket.

Finally, I will design the web interface, allowing connectivity and operation of the system.

I won't design valves, sensors, actuators, or power supplies; all these are going to be commercially available items that will be integrated into my final project.


What materials and components will be used?

Where will they come from?

How much will they cost?


To answer the questions above, I made a spreadsheet.

Materials and components What for Where they come from Links Qty Unit Price Total Price
MDF Forescolor for the enclosure Fablab Stock http://www.forescolor.com/product/ 900mm2 $0.000027/mm2 $0.02
Silicone for the gasket fablab stock https://www.amazon.es/LETS-RESIN-silicona-relaci%C3%B3n-manualmente/dp/B07V5FFPWC/ref=sr_1_109?dchild=1&keywords=silicone+molde&qid=1601471159&sr=8-109 50g $0.05/gram $2.39
Epoxy resin to further waterproof the interior of the enclosure and help with the light refraction of the LEDs fablab stock https://www.amazon.es/gp/product/B07KQ6Q5CB/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1 50ml $0.01/ml $0.60
          Total $3.01

Electronics Board

Value Package Description Where they come from Links Qty Pc Price Total Price
PCB blank   Proto Board Copper Clad FR1, Single Sided, 1 oz. 5.00" x 4.00" (127.0mm x 101.6mm) https://www.digikey.com/product-detail/en/bantam-tools/MT1004/1932-1038-ND/8567212 1 $2.44 $2.44
FTDI-SMD-HEADER 1X06SMD CONN HEADER R/A 6POS 2.54MM https://www.digikey.com/product-detail/en/adam-tech/PH1RB-06-UA/2057-PH1RB-06-UA-ND/9830592 1 $0.18 $0.18
22-23-2021 22-23-2021 CONN HEADER VERT 2POS 2.54MM https://www.digikey.com/products/en?keywords=22-23-2021 1 $0.17 $0.17
header2x6 2X03 CONN HEADER VERT 6POS 2.54MM https://www.digikey.com/product-detail/en/samtec-inc/TSW-103-07-F-D/SAM10846-ND/2685876 2 $0.48 $0.96
SWITCH SWITCH TACTILE SPST-NO 50MA 12V SWITCH TACTILE SPST-NO 50MA 12V https://www.digikey.com/product-detail/en/e-switch/TL3305BF260QG/EG5354CT-ND/5816199 2 $0.20 $0.40
0.1uF C1206FAB CAP CER 0.1UF 50V X7R 1206 https://www.digikey.com/product-detail/en/kemet/C1206C104K5RAC7800/399-C1206C104K5RAC7800CT-ND/411524 2 $0.11 $0.22
100uF C1206FAB CAP CER 100UF 10V X5R 1206 https://www.digikey.com/product-detail/en/tdk-corporation/C3216X5R1A107M160AC/445-6007-1-ND/2444048 1 $1.49 $1.49
15pf C1206FAB CAP CER 15PF 50V 1206 https://www.digikey.com/product-detail/en/kemet/C1206C150K5GACTU/399-9314-1-ND/3522832 2 $0.19 $0.38
1nF C1206FAB CAP CER 1206 1NF 250V X7R 10% https://www.digikey.com/product-detail/en/kemet/C1206C102KARECAUTO/399-17173-1-ND/8563714 1 $0.27 $0.27
ESP32-WROOM-32 (16MB) ESP-WROOM-32 WIFI MODULE 128MBITS SPI FLASH https://www.digikey.com/product-detail/en/espressif-systems/ESP32-WROOM-32-16MB/1904-1020-2-ND/9381713 1 $4.50 $4.50
LED LED1206 Standard LEDs - SMD 1206 Blue https://eu.mouser.com/productdetail/lumex/sml-lx1206usbc-tr?qs=UWUCXFQQ%252bdkNnUihARaICw== 7 $1.45 $10.15
100ohm R1206 RES SMD 100 OHM 1% 1/4W 1206 https://www.digikey.com/product-detail/en/panasonic-electronic-components/ERA-8AEB101V/P100BCCT-ND/3069515 5 $0.57 $2.85
10k R1206 RES SMD 10K OHM 1% 1/4W 1206 https://www.digikey.com/product-detail/en/bourns-inc/CRT1206-BY-1002ELF/CRT1206-BY-1002ELFCT-ND/1775051 3 $0.57 $1.71
1.2Mohm R1206 RES SMD 1.2M OHM 1% 1/4W 1206 https://www.digikey.com/product-detail/en/panasonic-electronic-components/ERJ-8GEYJ125V/P1-2MECT-ND/203263 1 $0.10 $0.10
1.5Mohm R1206 RES SMD 1.5M OHM 1% 1/4W 1206 https://www.digikey.com/product-detail/en/rohm-semiconductor/KTR18EZPF1504/RHM1-5MAICT-ND/4071441 1 $0.18 $0.18
150ohm R1206 RES SMD 15 OHM 1% 1/4W 1206 https://www.digikey.com/product-detail/en/yageo/RC1206JR-07150RL/311-150ERCT-ND/732170 2 $0.10 $0.20
1K R1206 RES SMD 1K OHM 1% 1/4W 1206 https://www.digikey.com/product-detail/en/panasonic-electronic-components/ERA-8AEB102V/P1-0KBCCT-ND/3069520 4 $0.57 $2.28
220omh R1206 RES SMD 220 OHM 1% 1/4W 1206 https://www.digikey.com/product-detail/en/stackpole-electronics-inc/RMCF1206FT220R/RMCF1206FT220RCT-ND/2418647 4 $0.10 $0.40
SRD-05VDC-SL-C RELAY_SRD-05VDC-SL-C SRD-5VDC-SL-C 5 Pin PCB Type https://www.banggood.com/Mini-5V-DC-Power-Relay-SRD-5VDC-SL-C-5-Pin-PCB-Type-p-930170.html?rmmds=buy&cur_warehouse=CN 4 $1.99 $7.96
ACS712 SO08 SENSOR CURRENT HALL 20A AC/DC https://www.digikey.com/product-detail/en/allegro-microsystems/ACS712ELCTR-20A-T/620-1190-2-ND/1284594 1 $2.32 $2.32
Diode SOD123 DIODE GEN PURP 100V 200MA SOD123 https://www.digikey.com/product-detail/en/on-semiconductor/MMSD4148T1G/MMSD4148T1GOSCT-ND/1121611 4 $0.13 $0.52
EL817(S)(D)(TU)-V SOIC254P1030X460-4N OPTOISOLTR 5KV TRANSISTOR 4-DIP https://www.digikey.com/product-detail/en/everlight-electronics-co-ltd/EL817/EL817-ND/2693260 4 $0.18 $0.72
BCX70SMD SOT23 TRANS NPN 45V 0.1A SOT23 https://www.digikey.com/product-detail/en/nexperia-usa-inc/BCX70K-215/1727-4918-1-ND/2531422 4 $0.19 $0.76
MCP1700T-3302E/TT SOT95P237X112-3N IC REG LINEAR 3.3V 250MA SOT23-3 https://www.digikey.com/product-detail/en/microchip-technology/MCP1700T-3302E-TT/MCP1700T3302ETTCT-ND/652677 1 $0.37 $0.37
TEMP-HUM-SENSOR-DHT11 TEMP-HUM-SENSOR-DHT11 SENSOR HUMID/TEMP 5V DTL 5% MOD https://www.digikey.com/products/en/sensors-transducers/humidity-moisture-sensors/529?k=DHT11 1 $5.00 $5.00
Screw Clamp W237-102 WAGO SCREW CLAMP https://www.aliexpress.com/item/33038876365.html?spm=a2g0o.productlist.0.0.668a28acJbQtwH&algo_pvid=1f4a38ed-b66c-47e9-9e25-39714f26a649&algo_expid=1f4a38ed-b66c-47e9-9e25-39714f26a649-5&btsid=0bb0623f16014685639395395e16d4&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_ 4 $0.10 $0.40
ECS-.327-12.5-13X XTAL_ECS-.327-12.5-13X CRYSTAL 32.7680KHZ 12.5PF TH https://www.digikey.com/products/en?keywords=ECS-.327-12.5-13X 1 $0.24 $0.24
          Total $44.73

What parts and systems will be made?

I will be making the enclosure, the PCB, as well as the gasket.


What processes will be used?


What questions need to be answered?

How can I make a web interface that communicates smoothly with C++? Maybe using the JSON protocol?

How do I set the time and prevent it from being lost during a power outage?


How will it be evaluated?

I think that to evaluate my project, one needs to review my objectives. My objectives with my final project were to have an irrigation controller on my fabfarm and at the same time learn code and electronics.

The following questions should allow one to evaluate the success of my final project: