Raspberry PI Spiderbot

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Revision as of 12:28, 25 July 2019 by Wf (talk | contribs) (→‎Parts)
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Inspired by the Arduino Project below we'd like to create a Raspberry PI version as in https://github.com/yasaspeiris/aragog

Video

Links

Parts

# picture part example sources documents ~ price
1 713LX1Z383L. SL1500 .jpg Raspberry PI 3 B+ Raspberry PI 3 B+ en 35 €
2 81UBu4aoQHL. SL1500 .jpg microSD Card SanDisk 16 GB 7 €
3 61Z5yEYfnAL. SL1426 .jpg Raspberry PI Camera 1080 p Camera Module 23 €
4 41smcErJNjL.jpg DC/DC Converter 12 V-> 5V 12 V->5 V Converter Module 7 €
5 31pzC7A3D3L.jpg Micro USB Connector Delock USB 2.0 Micro USB 6 €
6 SpiderBot-Parts-IMG 0033.JPG 3D Printed Parts: Coxa, Tibia, Femur, Hinge parts from regishu's design
7 61B2dK96ysL. SL1000 .jpg Adafruit PCA9685 16 channel PWM controller PCA9685 6.5 €
8 61yfILxEkgL. SX679 .jpg set of small screws set of small screws 8.5 €
9 71a1K3RQuqL. SX679 .jpg 12 x MG90S 12 x MG90s 42 €
Total ~ 135 €
a 71AYEqpWHcL. SL1500 .jpg Breadbord Kit MB102 Breadbord Kit 7 €
b 714Ep9LpwoL. SL1200 .jpg Ulrasound Sensor 5 x HC-SR04 + Cables 10 €

Printing

You might want to make sure that you print your parts with sufficient infill - I used 75%.

SpiderBotParts-IMG 0028.jpeg

Example for broken part

This part was printed with Cura's default infill an broke off:

Broken-IMG 0034.JPG

Assembly

  • Legs and hinges are connected with 1.4x5mm screws
  • Legs and servos are connected with 1.7x6mm screws

Leg IMG 0029.JPG LegConnection-IMG 0030.JPG

We use the raspberry base from https://github.com/yasaspeiris/aragog/blob/master/3d%20printed%20parts/base.STL

Plate-IMG 0033.JPG

Leg Test

sudo python3 testadafruit.py 0 1 2 3  0

Legs0-IMG 0030.JPG

sudo python3 testadafruit.py 0 1 2 3  90

Legs90-IMG 0031.JPG

sudo python3 testadafruit.py 0 1 2 3  180

Legs180-IMG 0032.JPG

testadafruit.py

# Test Adafruit 
# WF 2019-07-09
import sys
import time
from adafruit_servokit import ServoKit
kit = ServoKit(channels=16)

# 
# set the given angle for the given servos
#
def setAngle(servos,angle):
  print (angle)
  for id in servos:
    kit.servo[id].angle=angle
  time.sleep(0.3)

# Test Servo Software
servos=[]
args=len(sys.argv)
fromangle=0
toangle=180
step=1
if args>1:
  for port in range(1,args-1,1):
    servos.append(int(sys.argv[port]))
  anglestr=sys.argv[args-1]
  if "-" in anglestr:
    parts=anglestr.split("-") 
    fromangle=int(parts[0])
    toangle=int(parts[1])
  else:
    fromangle=int(anglestr)
    toangle=fromangle
else:
  servos.append(0)
  servos.append(1)
  servos.append(2)

if fromangle!=toangle:
  try:
    while True:
      for setangle in range(fromangle,toangle+step,step):
        setAngle(servos,setangle)
  except KeyboardInterrupt:
    print("Keyboard interrupt")
else:
  setAngle(servos,fromangle)

Evolution of Base

Since we'd like to use a Raspberry PI we couldn't use the orignal Base by regishu. Trying the one from https://github.com/yasaspeiris/aragog also did not work since our raspberry PI case hat a different size. So incrementally a new design was created:

Evolution of Base IMG 0030.JPG

Legtest 2

The three parts of a leg have been connected to the ports 10,11 and 12 and then the test was started with:

sudo python3 testadafruit.py 10 11 12 60-120

What Links Here