In the fall of 2018, I lost a hive due to yellow jackets. Yellow jackets are opportunistic and attack the hive in the early morning hours while the hive is asleep. This condition could be exacerbated by a wide opened hive entrance or a weakened hive due to other stressors. After some thought, I decided to try and modify a commercially available robbing screen by adding a servo motor to the top escape gate in an attempt to automatically lock down the hive during robbing times thereby denying yellow jacket access.

The yellow jacket gate utilizes a raspberry pi zero microcomputer and MG90S micro-servo motors. The raspberry pi zero runs a python script controlling the servos closing off the hive at 9:00pm and opening it at 9:00am by modifying the linux crontab file.

Close.py python script

import RPi.GPIO as GPIO

import time

servoPIN = 17

GPIO.setmode(GPIO.BCM)

GPIO.setup(servoPIN, GPIO.OUT)

p = GPIO.PWM(servoPIN, 50) # GPIO 17 for PWM with 50Hz

p.start(2) # Initialization

print ("90 degrees")

print('\a')

p.ChangeDutyCycle(7)

time.sleep(.5)

p.stop()

GPIO.cleanup()

Open.py python script

import RPi.GPIO as GPIO

import time

servoPIN = 17

GPIO.setmode(GPIO.BCM)

GPIO.setup(servoPIN, GPIO.OUT)

p = GPIO.PWM(servoPIN, 50) # GPIO 17 for PWM with 50Hz

p.start(2) # Initialization

print ("0 degrees")

print('\a')

p.ChangeDutyCycle(2)

time.sleep(.5)

p.stop()

GPIO.cleanup()

Sudo Crontab -e

# For example, you can run a backup of all your user accounts

# at 5 a.m every week with:

# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/

#

# For more information see the manual pages of crontab(5) and cron(8)

#

# m h dom mon dow command

00 09 * * * python /home/pi/Desktop/open.py

00 21 * * * python /home/pi/Desktop/close.py