Introduction
This project is a continuation of the work done by Sumit , which you can find at the following link: [insert link here]. The main goal of this project is to improve the current scarecrow design to prepare it for future commercialization.
The Project: A Two-Part Endeavor
- Strengthening the Structure: We aim to make the scarecrow more resilient by developing a 3D printed part that connects the pole to the body of the scarecrow.
- Affordability and Commercial Viability: We are also working to make the product more affordable and market-ready by creating a PCB (Printed Circuit Board) that consolidates all the necessary electronic functions.
Part I: 3D Printing
The objective here is to create a modular and adaptable piece that can withstand the forces exerted on the scarecrow due to strong wind movements in the fields. You can view the finished piece and associated plans here.
A final version has been updated to include a hole in the pole for screwing purposes and a slight elongation of the two arms to increase resistance.
All parts and plans are available on the following GitHub repository: [insert link here].
Part II: Electronics
The current system relies on commercially available parts that require assembly. These parts have more functionality than needed for the scarecrow, which is why we decided to create our own PCB that consolidates all these functions, reducing costs and increasing the product’s longevity.
Previous Model Overview:
Two main electronic functions need to be realized:
- Economical Timer: To control the scarecrow’s movements.
- Economical Sound System: For our product.
a. Economical Timer: Based on the NE555 module, which is particularly interesting for fixed-time systems. It only requires two resistors and a capacitor to operate. We use the Timer555 in its astable mode (see diagram) more information on this device in this tutorial.
The choice of resistors and capacitor is based on the following formulas:
T = 0.693 *( R1 + R2) *C : Time High
T = 0.693 * R2 * C : Time Low
To simplify, you can use the following website to get direct values for a given pair (R1, R2, C1): link.
In our case, for a total operation of X minutes and Y minutes of movement, the resistances R1, R2, C1 are equal to ().
Premier test realise avec jumper et alim de labo :
b. Economical Sound System: Requires two new components: an MP3 module and an amplifier.
The MP3 module retrieves sound from an SD card and converts it into a signal that the speaker can understand. However, as the output signal is too weak, an amplifier is added to increase the sound signal’s power from the MP3.
The new system thus includes these components (see Figure X).
Module used
MP3 : datasheet
Ampli : datasheet
Part 3 Price Comparison:
Old version material cost: [insert cost here].
| Old version | |
| Music | 650 |
| Timer | 250 Rs |
| Total | 900 |
New version material cost (including PCB): [insert cost here].
| New version | |
| MP3 module | 100 Rs |
| Amplifier | 95 Rs |
| Ne555 | 19 Rs |
| Relay | 55 Rs |
| Resistor (9MOhm & 1MOhm) | 10 Rs |
| Capacitor (1000uF) | 15 Rs |
| Total | 294 Rs (195+99) |
This results in savings of X Rs.
PART 4 Creating a PCB:
Finally, we need to create a PCB that brings all these components together into a single module.
The PCB plans will be available here soon: [insert link when ready].
Timer pcb part :
Here’s a list of the necessary components with their names, prices, quantity, and supplier links: [insert list here].
| New version | Price | Quantity | Supplier link |
| MP3 module | 100 Rs | 1 | https://robu.in/product/mp3-tf-16p-mp3-disk-tf-card-module-serial-port/ |
| Amplifier | 95 Rs | 1 | https://robu.in/product/tda2030a-6-12v-18w-audio-amplifier-module/ |
| Ne555 | 19 Rs | 1 | https://robu.in/product/ne555dr-texas-instruments-precision-timer-ic-timing-microseconds-to-hours-ttl-astable-monostable-4-5-v-to-16-v-soic-8/ |
| Relay | 55 Rs | 1 | https://robu.in/product/12v-1-channel-relay-module/ |
| DC motor | 1 | ||
| Resistor (9MOhm & 1MOhm) | 5/5 Rs | 1/1 | https://robu.in/product/10m-ohm-1-4w-0603-surface-mount-chip-resistor-pack-of-100/ https://robu.in/product/1m-ohm-1-4w-0603-surface-mount-chip-resistor-pack-of-100/ |
| Capacitor (1000uF) | 15 Rs | 1 | https://robu.in/product/1000uf-25v-electrolytic-capacitor-dip-pack-of-5/ |
| Switch ON/off | 1 | ||
| Speaker | 1 | ||
| Pcb itself | 1 | ||
| Total |
