In this project I will show you how to build a solar-powered Raft Bird Repeller that will get rid of those pesky birds that poop on your raft.
Step 1: Intro
If you have ever been on a raft, you know just how relaxing and fun they can be to hang out on. One thing that is definitely not relaxing or fun is cleaning up the bird poop on them. This has been a problem as long as I can remember and my mom has tried every bird repeller device on the market from owls, sounds, bird barriers, and bird tape to no success. Mothers day was coming up and I decided to attempt to be a good son and give her a gift she has always wanted, no more bird poop on the raft.
After looking at all the bird repeller devices on the market today and reading their reviews, I came to realize that most of them do not work all that great or at least not for all types of birds. For my device, I figured if the birds were not physically able to sit and poop on the raft, that I would have near 100% no-poop success rate. I decided that if I could have two retractable poles mounted on a spinning plate connected to a relatively high torque dc motor then I could trigger the motor to spin on a timer and repel the birds away. I needed the device to be solar-powered and contain a microcontroller which I connected to a real-time clock so I could only enable the spinning mechanism during the day and reserve power for nighttime. I also needed it to be waterproof and float so if someone wanted to use the raft, they could retract the poles, attach it to the raft, and throw it in the water.
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Step 2: Components Needed
The components needed for this project are below:
1. 12V 7AH SLA Battery
2. Charge Controller
3. 10W Solar Panel
4. Fuses (5A, 2A, 2A)
5. On/Off Switch
6. 12V / 5V Step Down Module
7. Geared DC Motor 11 RPM
9. DS3231 RTC Module with coin cell
10. Resistors (2x 4.7K, 10k, 100 Ohm)
11. IRF540 Mosfet
12. 2 Diodes
13. 2x Telescopic Poles (I reused old teachers pointer poles)
14. Waterproof Enclosure Box and some type of vented enclosure for SLA battery
15. 2x Stainless Steel Wire Rope Clips
16. M4 Screws
17. Circular piece of metal
18. Pololu 1083 Universal Aluminum MOUNTING HUB for 6mm Shaft Pair, 4-40 Holes
19. Solar Panel Z Brackets for Mounting
20. Wood and Screws
21. 2 Plastic Cable Glands
22. Optional: Access to 3D Printer for Rings
Step 3: Electronics
Now that you have gathered all of the required components, it is time to start assembling everything together. I would recommend wiring up everything on a breadboard first and then once everything is functioning properly go ahead and solder everything up on a perf board.
The microcontroller used for this circuit is the Attiny85 for its low power consumption. It also has 8k of program space, 6 I/O lines, and a 4-channel 10 bit ADC. It runs up to 20 MHz with an external crystal. This chip is only about $2 and is perfect for simple projects where an Arduino is overkill like this one.
The RTC used is the DS3231 which is a low-cost, extremely accurate I2C real-time clock (RTC) with an integrated temperature compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input, and maintains accurate timekeeping when main power to the device is interrupted. This will be crucial if for any reason the bird spinner cycles power, the timing of the dc motor turning on and off will be reserved by the RTC. I also just wanted to try out I2C on the Attiny85.
The plate with the two telescopic stainless steel poles is fairly heavy, so I knew that I needed a higher torque dc motor that would run off 12V and provide the speed that i was looking for to not injure the birds, but let them know this contraption wasn't messing around.
Since mothers day was rapidly approaching I needed something quick that could drop 12V to 5V to power the Attiny85 and the RTC. I found a pre-built step down converter with 96% efficiency so that would obviously work much better than using a 7805 and losing power due to heat.
The main power for this project was from a 10W solar panel and a 12V 7AH SLA battery. I connected those up to a charge controller to handle powering the load and charging the battery.
Step 4: PCB Design
I also designed a simple PCB in KiCad that has a LM2576 voltage regulator so I eventually won't need the external DC-DC converter. I haven't had time to install it on the raft yet but everything works properly when connected to a 12v DC Motor.
I have attached the gerbers below.
Step 5: Programming
I will assume that you know how to setup the Arduino enviroment to program the Attiny85 but if not there are many great tutorials online.
You will need to install the following libraries in order for the code to compile.
Other than that the program is very simple but you are required to fill in a few values:
First, the TimeOff and TimeOn variables which correlate to when the bird repeller code should be on. So if you put TimeOn to 8 and TimeOff to 18 that would mean the repeller is on from 8:00 AM until 6:00 PM.
Second, the TimeMotorOn and TimeMotorOff variables which are the time that you want the motor to turn on for and it will be triggered when TimeMotorOff expires. So if you put TimeMotorOn to 10 seconds and TimeMotorOff to 3 minutes, the motor would turn on for 10 seconds every 3 minutes.
Once you enter in the values that you want, then compile and upload to the Attiny85. I used sparkfuns tinyAVR programmer because it makes programming these chips very easy.
Step 6: Assembling the Spinning Mechanism
I tried to not spend alot of money on this project so for the spinning mechanism I found a circular metal plate at a local hardware store. I also found some stainless steel wire cable rope clamps that I figured could be used to clamp down the poles. The poles are two telescopic poles which I originally found at a local goodwill and they were standard ones used by teachers. I ripped the foam handles off and clamped them down to the metal plate using the rope clamps. Eventually I want to replace these with plastic telescopic poles but I haven't found any cheap lightweight ones yet. I am sure there are better ways to do this but it has worked great so far.
Step 7: Building the Raft
The entire device needed to be on a small raft since I wanted to have the ability to throw it in the water when people wanted to use the raft. I could then use a rope to attach the device to the raft while it is in the water so when people are getting off the raft, they could just reel it back in and set it up. If they turn the switch to off when they put it in the water, then the battery will get some extra power from the solar panel since it no longer needs to power the load.
You don't have to make the exact raft that I decided to make but if you want to then the instructions are below.
- Screws (I used deck screws)
- 1 x 6 Standard Pine (12ft x 2)
- 2 x 4 (8ft)
Cut the 1x6 boards into 2 foot increments. They will be used for the top of the raft.
Cut the 2x4 boards into two 24 inch boards and three 16 inch boards. This will be for laying out the bottom of the raft.
Screw all of the wood together in a 2ft square. Mine ended up floating but waves could cause issues so I added some foam panels and more wood to make it float alot better.
Step 8: Mount Components on Raft
In this step, you will need to mount all of the components onto the raft. This includes the solar panel, the SLA battery in vented enclosure, and the spinning mechanism with the enclosed electronics.
Center the SLA battery enclosure on the raft and using screws attach the case firmly to the raft.
For the solar panel, screw in the solar panel mounting brackets and attach the brackets to the solar panel using some nuts and bolts that come with the bracket.
The enlosure for the dc motor and electronics, I elevated a bit using some 1x6 pieces of wood and screwed the wood and the enclosure down.
Wire up the battery and the solar panel.
Step 9: 3D Design/Print
I know that there are alot of great ways to make the hole that connects the motor shaft to the spinning plate waterproof but I didn't have much time so I decided to just print and glue a few rings that should keep out the majority of the water. It works great against the rain and hopefully the raft will never get flipped over.
Step 10: Test It Out!
Now that you have the raft bird repeller all assembled and programmed, it is time to test it out!
Plug it in, install all the fuses, turn on the switch, and enjoy a bird poop free raft.
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Thank you for reading!
Participated in the
Arduino Contest 2019