Introduction: Seed Spreading Robot

Inalterable summer it was brought to my attention that you could buy nearly everything you needed for automated lawn care but a sow spreading robot. This intrigued me. For starters, wherefore on Earth would anyone make lawn aid robots in the first place? Thither are countless reasons this seems like a bad idea. Secondly, a source spreading robot sounded like a bizarre robotic cross between Wall-E, and Johnny Appleseed. The idea clearly had potential difference.

So, when asked if I wanted to actually take on the challenge of building one, I apparently responded with a definitive yes. Even though I in person don't own a lawn (my backyard is concrete and weeds), it seemed like an opportunity to a fault good to give-up the ghost up. In terms of actually using it, I found a inclined dupe in Glenn Derene of Popular Mechanics. Atomic number 2 was more than blissful to let this affair loose on his lawn (along with a slew of else robotic lawn care contraptions). Soh one fateful Clarence Day last summer, I tightened the last bolt, wrote the sunset dividing line of code, jammed IT up safely, and shipped it cross country to meet whatever fate lie in store.

Albeit I only subsequent proverb a video of it in execute, information technology is my sympathy that IT performed around besides As you would expect an experimental DIY seed spreading golem to perform on its initial run; in short, not very. Rather than a cross between Wall-E and Johnny Appleseed, it is more of a cross between Johnny Reb 5, and the groundskeeper in Caddyshack.

Nonetheless, I think the geophysical science design of the robot is solid. If the code is tweaked a little, and the rangefinder repositioned, I think this robot could spread seed like a champ.

Step 1: Go Obtain Stuff

You will need:

(x1) Lynxmotion Tri-Track Chassis Kit
(x1) Earthway EV-M-Spred Seed Hopper (operating theater similar)
(x1) Arduino Uno
(x1) Arduino Efferent Harbour
(x1) Parallax Ping Rangefinder Sensor
(x1) 1/4 Scale Servo
(x1) Lynxmotion 12v battery
(x1) Vex battery courser
(x1) District of Columbia power punch
(x3) Useful PCB
(x1) 7805 electric potential regulator
(x1) Heat sink
(x1) Thermal transplant glue
(x1) 10 uF electrical condenser
(x4) 0.1uF capacitor
(x1) 1K resistor
(x20) Header pins
(x1) ATS177 hallway effect sensor
(x2) 1/8" rare earth magnet
(x4) 1-1/4" aluminium spacers
(x4) 1-1/2" x 6-32 nuts and bolts
(x1) 12" x 24" x 1/8" acrylic
(x1) 6" x 6" x 1/4" plyboard
(x12) 1/4" nylon spacers
(x12) 1" x 6-32 nutty and bolts
(x4) 1-1/2" x 4-40 nuts and bolts
(x8) 1/4" nylon spacers
(x6) pens
(x6) 1/4 x 6" balmy and bolts
(x4) 1-1/4" aluminum spacers
(x4) 2" x 6-32 crackers and bolts
(x1) Assorted zip ties
(x1) Assorted shrink tubing
(x1) Krazy Paste (gel)
(x1) Thread engage
(x1) 24" x 24" cardboard sheet

You will also need to download and cut out the pursuit files:

SensorHolder.eps -- cut out of 1/8" acrylic and etch away the black square 1/16" down
HopperDrillBracket.eps -- trim retired of composition board
TopBracket.eps -- incised out of 1/8" acrylic resin
ServoBracket.eps -- scratch out of 1/8" acrylic
ServoConnector.eps -- cut off of 1/4" plywood
BottomDrillBracket.eps -- cut back out of cardboard
PingBracket.eps -- cut of 1/8" acrylate resin


(Note that some of the links on this page are affiliate links. This does not shift the cost of the item for you. I reinvest whatever proceeds I pick up into making new projects. If you would like whatsoever suggestions for alternative suppliers, please let me know.)

Pace 2: Tack together the Treads

Set up the treads past lining them risen side-by-side, inserting a clear tube 'tween the straight rings, and pressure in the plastic pins until they snap in situ.

You should beryllium left with two stretch strips. Set digression the hardware necessary for closing the loops for later.

Step 3: Attach Spacers

Find the deuce triangular lexan panels with interior mounting slots and holes. Impound the aluminum spacers using 4-40 x 3/8" bolts, so much that they mirror each other, and are not selfsame copies.

Step 4: Attach the Motor

On one of the triangular lexan panels, inset a motor shaft through the largest mounting maw such that it is pointing in the same direction arsenic the aluminum standoffs.

If you have not done so already, cold shoulder out a 1/8" acrylic sensor holder using the attached pattern. Where the figure has a black square, etch halfway into the acrylic to make a channel to mountain the detector.

Align the acrylic sensor bearer with the motor mounting holes. Fix the motive and the acrylic resin sensor holder in rank with 3mm x 8mm steel screws.

Step 5: Attach the Other Motor

Attach the other motor in a kindred manner to the previous uncomparable. However, do not worry about climb an acrylic sensor holder on this side.

Step 6: Drill Holes

Drill a 1/16" hole directly to a higher place the acrylic sensor holder that is central along the width of the etched square. Drill two more holes that are aligned with the corners of the etched square.

Step out 7: Rotational Counter

Bend the hall force detector leads to a quadrant (away from the text). Insert the hall effect sensor leads through with the three holes that you just drilled and position information technology snugly in place. When you birth managed to get information technology flush with the surface of the acrylic sensor holder, glue the sensor in place.

Step 8: Hub Counter

Find one of the hubs that slides on the motor shaft.

Cover the threads of two 4-40 x 3/8" bolts and draw them the whole way down into the hub such that they are opposite from each other.

Now is fourth dimension to place magnets upon the head of from each one bolt and glue them in place. However, before gluing, information technology is important that the magnets are facing in the correct cold direction.

Here is approximately basic code for checking the hall effect sensing element and devising certain that you put the side of the magnet that triggers the sensor facing prepared atop the bolt.

          
        
        
          
Step 9: Attach the Hubs
          
            
Attach the hub with the magnets to the motor shaft of the assembly with the foyer effect sensing element such that the top of the hub is flush with the top of the motorial scape.
            
              Repeat this process for the other hub and motor screw.
          
        
        
          
Step 10: Attach a Sprocket
          
Place in collaboration two sprocket halves and bolt them to the hub without the hall gist sensor using 4x40 x 5/8" bolts.
        
        
          
Step 11: Trim a Cog
          
            
Take one of the sprockets and slice away the outer rim with a saw such that the teeth are flush with the margin.
            
              This sprocket wheel will equal used on the in spite of appearanc butt on of the motor hub with the magnets attached. This will allow information technology to turn out without rubbing against the hall core sensor bracket.
          
        
        
          
Step 12: Bond Trimmed Sprocket
          
            
Attach the trimmed cog facing in towards the manse effect sensor, and an unaltered socket facing outwards.
            
              Fasten them both in situ with 4-40 x 5/8" bolts.
          
        
        
          
Step 13: Crimper Sprockets
          
            
Put together a roller cog past inserting an idler hub through the center holes of two sprocket halves. Fasten the assembly with 3mm x 8mm brand bolts.
            
              Repeat other 3 times.            
          
        
        
          
Step 14: Mounting Blocks
          
Attach the climb blocks to the many-sided lexan panel on the unvaried side as the motor body using 4-40 x 3/8" bolts.
        
        
          
Maltreat 15: Gather
          
            
Put up the roller sprockets in place.
            
              Cover each of the Al spacers with a nylon roller.
            
              Finally, finish the assembly by aligning the unsused three-way lexan panels all over the spacers and lockup them in place with 4-40 x 3/8" bolts.
          
        
        
          
Stair 16: Wrap the Treads
          
            
Twine the treads around the motorized sprocket assembly.
            
              Make a point they are aligned properly over the sprockets, so close the final gene linkage to complete the loop topology.
          
        
        
          
Step 17: Remove the Lever
          
Take the methamphetamine lever from the seed broadcaster.
        
        
          
Step 18: Remove Screws
          
Remove the screws holding the gear box cover in place.
        
        
          
Stair 19: Bore Holes
          
            
Open up the seed spreader's gear box and remove the large gear.
            
              Print out the attached template and use it A a guide to make marks for drilling.
            
              Practice session through those tetrad marks with 1/8" drill bits.
          
        
        
          
Stride 20: Bolt Together
          
            
Insert 1" x 6-32 bolts through the four holes that were just drilled from the inside on out.
            
              Cut the top 1/8" acrylic resin bracket if you have non cooked so already exploitation the attached guide.
            
              Slide the top acrylic resin square bracket onto these bolts and fasten it into place.
          
        
        
          
Step 21: Seed Broadcaster Brackets
          
Cut two acrylic fiber control system brackets to affix the servo motor to the seed broadcaster using the attached files.
        
        
          
Whole step 22: Careful It Raised
          
            
Insert the oversize gear back into place, put the gear box seat cover back connected, and place the acrylic servo bracket with the large center hole over the cover so that the outer climb holes lines up with the spreader's bolt holes.
            
              Use the gear package mounting screws to firm impending the case and hold the bracket in come out.
          
        
        
          
Step 23: Insert Servo
          
Insert the servosystem into the another acrylic servomechanical bracket with the large perpendicular gob. Bolt the servo into put with 6-32 x 1" nuts and bolts.
        
        
          
Whole tone 24: Servo Connector
          
Cut cardinal servo connectors out of 1/4" plywood victimisation the affianced template.
        
        
          
Stride 25: Drill
          
Drill holes in the servo's horn using a 3/16" drill scra.
        
        
          
Step 26: Affix
          
            
Zip tie the servo tusk to the awkward servo connector. Trim away any excess zip tie tails.
            
              Advertize this assembly onto the servo shaft.
          
        
        
          
Step 27: Servo Assembly
          
Connect the two acrylic servo brackets together with 2" nuts and bolts, victimization 1-1/4" spacers in between. Also, while doing so, insert the seed spreader's crank shaft into the center of the wooden servo connexion. In this way, when the servosystem rotates, the crank shaft should turn.          
        
        
          
Step 28: Drill the Foot
          
Download the attached boring guide and habit it to drill half a dozen 1/4" holes along the outside edges of the bottom lexan impanel.
        
        
          
Step 29: Attach Ground Spacers
          
Attach aluminum spacers on the two center rows of holes of the bottom lexan impanel (the one without the large rectangular hole) victimisation 4-40 x 3/8" bolts.
        
        
          
Step 30: Mark and Drill
          
            
Place the Arduino and one fractional of the multiple miniskirt circuit boards onto the back nitty-gritty of the as lexan panel (the side that narrows).
            
              Make marks for drilling.
            
              Drill all of these holes with a 1/8" drill second.
          
        
        
          
Step 31: Heat Sink
          
Apply thermal compound to the back of the 7805 voltage governor, and then bolt it to the fire u sink.
        
        
          
Step 32: Set about the Power Board
          
            
Solder the 7805 regulator to the paid board.
            
              Solder a 10uF / 50v capacitor between Vin and priming coat, qualification doomed the negative lead goes to ground.
            
              Solder a 0.1uF capacitor between the regulated Vout and ground.
          
        
        
          
Step 33: Finish the Power Board
          
            
Solder the non-buoyant gauge red wire with the switch attached (break of track chassis kit) to Vin and the heavy gauge black telegraph to ground.
            
              Solder two additional stranded wires to ground.
            
              Solder other stranded wire to Vin, and a different wire to Vout (but you may not need this wire).
          
        
        
          
Step 34: Mod the Motor Restrainer
          
Slue off the Vin rowlock from the drive controller to separate the motor controller shell from the Arduino mogul source and service prevent likely short circuits.
        
        
          
Step 35: Insert
          
Insert the modded motor controller shield into the Arduino.
        
        
          
Step 36: Attach the Arduino
          
Attach the Arduino to the lexan base plate by putt information technology on 1/4" nylon spacers and bolting IT in place with 4-40 x 2" haywire and bolts.
        
        
          
Step 37: Attach the Index Board
          
Set down the power plank atop 1/4" nylon spacers and fix it in place with 6-32 x 1" nuts and bolts.          
        
        
          
Step 38: Pen Tubes
          
Carry divided six pens so that you can usage the hollow tubes.
        
        
          
Step 39: Assemble the Base
          
            
Pass 6" x 1/4 bolts up through the six 1/4" holes that were drilled earlier in the upper lexan base panel.
            
              Place the upper lexan base panel atop the aluminum spacers attached to the bottom control panel. Fasten the top panel in place using 4-40 x 3/8" bolts.
          
        
        
          
Abuse 40: Screening the Bolts
          
Glide the pen tubes over the 6" bolts, such that they are working as spacers.
        
        
          
Step 41: Fundament to Top
          
Insert the tips of the 6" bolts done the mounting holes in the acrylic bracket connected to the seed spreader and fasten it unwaveringly in place exploitation 1/4 nuts.          
        
        
          
Step 42: Capacitors
          
Solder 0.1uF capacitors between the motor terminals in much a manner that you pot still slide the drive wire connective cables onto the last.          
        
        
          
Step 43: Put It All Together
          
            
Slue the base lexan base into the the slots on the track assemblies.
            
              Fasten the lexan base to the atomic number 13 climb blocks on the track assemblies using 4-40 x 3/8" bolts.            
          
        
        
          
Abuse 44: Insert the Switch
          
Pass the toggle switch that is connected to the thickheaded battery cable through the remaining 1/4" hole in the superior lexan base assembly. Fasten it in place with its mounting nut.
        
        
          
Step 45: Wire the Plug
          
            
Contain united of the red wires soldered to 12v on the baron board and some other that is soldered to ground.
            
              Screw apart the plug assembly and chute the cover onto the wires.
            
              Solder the red wire to the center terminal and the black telegram to the outer last, and trim any excess so that they don't bridge.
            
              Screw the cover back on when you are finished.
          
        
        
          
Pace 46: Insert
          
Insert the M-Type plug into the Vin socket on the Arduino.
        
        
          
Mistreat 47: Trimness
          
Take a prototype electrical circuit board and diluted IT down to be 1" by  3/4". I find a standard pair off of scissor grip or a paper cutter work well for press cutting up circuit boards.
        
        
          
Step 48: Range Finding Assembly
          
            
If you have not finished so already, download the attached template and use it to cut a rangefinder angle bracket stunned of 1/8" acrylic.
            
              Pass the range finder leads through the ternary belittled holes in the frontmost of the bracket such that the rangefinder is approximately seamed up with the margin of the bracket.
            
              Slide the circuit board onto the rangefinder leads and solder information technology into place.
            
              Severally insert 6" red, melanise, and William Green wires through the three other midget holes in the acrylic paint, and forward through holes in the PCB. Solder them in spot besides.
            
              Link up and solder the red wire to the 5v pin on the range finder.
            
              Touch base and solder the black wire to the ground pin on the rangefinder.
            
              Connect and solder the green wire to the data pin on the rangefinder.
          
        
        
          
Tread 49: Attach the Rangefinder
          
Mount the rate finder to the front servo mounting holes in the upper lexan bracket atop 1/4" nylon spacers using 1" x 6-32 bats and bolts.
        
        
          
Step 50: Head Pins
          
            
Insert three lintel pins into the 5V power and two ground sockets on the Arduino. Put in other five cope pins into the appendage pin sockets 2 done 7.
            
              Also, enclose ii headers into extremity pins 9 and 10 (not pictured).
            
              Donjon the headers in place, and compress down a prototype circuit board onto them.
            
              Solder the headers to the circuit display panel.
          
        
        
          
Tread 51: Start the Circuit
          
            
Solder a 3 pin head to the pinch side of the circuit control board. Connect cardinal of the outside pins to ground, the center pin to 5V, and the other outer pin to member PIN 10 (pictured incorrectly).
            
              Solder a 1K resistor and 0.1uF capacitor in serial publication on the electric circuit board. Connect their center point to digital pin 5.
          
        
        
          
Step 52: Wire Up the Hall Effect Sensor
          
            
Attach a 6" red wire to the outside power pin on the hall effect sensor.
            
              Attach a 6" black wire to the center ground pin connected the hall effect sensor.
            
              Attach a 6" green wire to the outer betoken pin on the hall effect sensor.
            
              Put down heat shrink tube over each of these connections severally, and zip affiliation them together for strain relief.            
          
        
        
          
Step 53: Wire in the Hall Upshot Sensor
          
            
Seize the super acid wire to the central junction 'tween the 1K resistance and 0.1uF capacitors (that is already also connected to extremity immobilise 5).
            
              Solder the black wire to the past leg of the 0.1uF capacitor.
            
              Solder the red wire to the other stage of the 1K resistor.            
          
        
        
          
Stone's throw 54: Solder the Range finder
          
            
Solder the green wire from the rangefinder to digital pin 7 on the Arduino.
            
              Solder the red wire to the Arduino's 5V pin, and the black wire to the Arduino's priming coat pins.
          
        
        
          
Step 55: Plug in the Servo
          
Hack the servo into the header pins that were attached earliest. Make sure that the servomechanism's yellow wire is going to digital pin 10 on the Arduino.
        
        
          
Step 56: Connect the Motors
          
Attach to the motor connector wires to the motors aside sliding them onto the drive terminals such that both yellow wires go to the plus terminal and both green wires exit to ground.          
        
        
          
Step 57: Wire the Efferent Shield
          
            
Insert the red telegram from the motor on the right to the dismissive closing of channel "A" on the efferent shield. Put in the dishonourable telegraph from the right motor into the positive period of time of channel "A".
            
              Slip in the red wire from the motor on the left to the negative time period of channel "B" connected the motor shield. Insert the yellow wire from the right motorial into the prescribed terminal of channel "B".
            
              Insert the remaining 12v wire from the power circuit board into the Vin concluding, and the base wire into the ground terminal.            
          
        
        
          
Mistreat 58: Attach the Battery
          
Office the battery between the two motors and zip tie up it into order.          
        
        
          
Step 59: Touch base
          
Hack the battery connector into the socket coming from the switch / power gameboard.
        
        
          
Footmark 60: Program
          
            
              Program the Arduino with the following code:
            
          
        
        
          
Abuse 61: Engage the Seed Spreader
          
Engage the seed spreader by zip tying the trigger down. It is non very high technology, but IT gets the job done.          
        
        
          
Ill-use 62: Power
          
Affiance the robot by flicking the little lever exchange.          
        
        
          
Step 63: Pour Seed
          
Fill the seed spreader about 3/4 of the way with green goddess sow.
        
        
          
Step 64: Positioning
          
Assuming your lawn is square and has an L-shaped fence (operating room U-shaped fence... surgery you are a total looney and IT is whole penned...), grade the robot such that it is pointing in a straight seam towards the end segment of the L, and will glucinium turn right to move to the side wall. If this verbal description makes little horse sense, check out the diagram.
        
        
          
Step 65: Go under Use It
          
            
Basically, the way that this is working is that information technology engages the seed spreader, travels towards the far fence, and counts the number of motive rotations it takes to get there. Once it is inside a a couple of inches of the wall, it turns right and travels about a foot and a half (disengaging the seed broadcaster). It then turns right again and travels back across the lawn (engaging the seed spreader). However, since there is no thirster a palisade to sense, the robot counts the issue of motor rotations and travels spinal column the same distance it traveled towards the wall. When it gets back to this side, it turns left, travels about a foot and a half (disengaging the seed spreader), turns left once again (engaging the seed spreader), and so repeats the mundane. The routine is repeated until it turns to the side and encounters the face wall inside a substructure's distance (surgery thus).
            
In theory, the robot should perfectly cover the lawn with grass seed. In reality, IT will pull off probably draw a weird modernist zig zag pattern.
            
Same stellar affair which still needs tweaking is that inserting gage seed makes the bot topmost heavy and forces the rangefinder sensor to manoeuver slightly downwards. As the robot bounces along the lawn, it sometimes senses the ground and stops short of the wall. I think this can be solved by angling the sensor upwards and adding more or less debouncing to the code.
            
This is still a work in progress and I welcome anyone who thinks that they can spring up better solutions to this problem to take a stab at it.
            
                          
            
              
                Did you find this useful, fun, or entertaining?
                Trace                @madeineuphoria                to see my latest projects.
            
          
        
        
          
            Be the First to Share          
        
        
          
Recommendations