Welcome back to Day 11 of 12 Days of Arduino! Today I backtrack a bit and tie up some “loose ends” with the design.
The HC-06 that I am using states that it needs 3.3v on the rx, not 5v as I had it set up yesterday. We’ll want to comply with this to avoid damaging any components. A simple way to go about this is to create a voltage divider using a couple resistors. I use this handy tool that does all the math for you to figure out what resistance resistors are necessary to get our voltage down to 3.3v: Voltage Divider Calculator. I ended up going with a 1k and a 2k resistor to obtain close to 3.3v.

Pro Tip: You won’t find this in most tutorials or datasheets, the heatsink tab of the TIP120 is directly connected to the Collector.

Because of the heat sink I had connected to both the Tip120’s, when the circuit would close it would also close the circuit to the transistor that was also connected to the heatsink. So unfortunately I had to remove the cool looking heat sink which honestly was probably complete overkill in the first place, more aesthetic than functional, so it’s probably for the best! That being said.

Parts:
-Arduino Uno R3
-Motor
-Fan
-Jumper Wires
-Breadboard
-Spam Can
-2x TIP120 transistors
-HC-05 or HC-06
–3d printed core
-1k resistor
-2k resistor

All code on this site is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

#include

if(motorBool == true){
analogWrite (motor, 255);
bluetooth.print("motor:");
bluetooth.println(motorBool, DEC);
}
else{
analogWrite (motor, 0);
bluetooth.print("motor:");
bluetooth.println(motorBool, DEC);
}
if(fanBool == true){
analogWrite (fan, 255);
bluetooth.print("fan:");
bluetooth.println(fanBool, DEC);
}
else{
analogWrite (fan, 0);
bluetooth.print("fan:");
bluetooth.println(fanBool, DEC);
}
delay(1000);
}

I didn’t have time today to get as much done as I would like, so tomorrow will be a big day! That or I may have to extend it to day 13… Tomorrow I’ll put everything together and we will take Spambot for a stroll!

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Day 12 →

The post 12 Days of Arduino Day 11 – Robot Drive and Controls appeared first on Kevin Gulling - Game Development, VR, and more.

Welcome back to 12 Days of Arduino Day 10. Today we finish the core and connect to a remote computer via bluetooth. Everything has been pretty simple up until this point, so if you are a beginner you might want to watch some tutorials on YouTube and read up on the HC-05 and HC-06 before-hand.

Parts:
-Arduino Uno R3
-Motor
-Fan
-Jumper Wires
-Breadboard
-Spam Can
-2x TIP120 transistors
-HC-05 or HC-06

Bluetooth Sketch

#include <SoftwareSerial.h>

void loop() {
// put your main code here, to run repeatedly:
if(bluetooth.available()>0){
bluetooth.print("I received: ");
bluetooth.println(incomingByte, DEC);
}
analogWrite (motor, 255);
digitalWrite (fan, HIGH);
delay(1000);
}

Pro Tip: If you have issues uploading your sketch, unplug the Bluetooth module from the rx/tx pins.

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The post 12 Days of Arduino Day 10 – Robot Bluetooth Connection appeared first on Kevin Gulling - Game Development, VR, and more.

Day 9 of 12 Days of Arduino! So I couldn’t wait to get our components hooked up to the core, aka the spam can so I jumped ahead of schedule a bit so we can see the robot start to take shape! Don’t worry though, there’s more to this surprise! Make sure you catch Day 10-12, and if you’ve missed it, go back and check out the “Keyduino“.

Parts:
-Arduino Uno R3
-Motor
-Fan
-Jumper Wires
-Breadboard
-Spam Can
-2x TIP120 transistors

One motor for the driver and one for the cooling

int motor = 3;
int fan = 5;

void setup () {
pinMode (motor, OUTPUT);
pinMode (fan, OUTPUT);
}
void loop () {
analogWrite (motor, 255);
digitalWrite (fan, HIGH);
}
This old fan that I scrapped off a GPU from the turn of the millennium has seen better days. It was not responding to anything less than 12v therefor I simply gave it a digitalWrite to HIGH, so I’ll likely be swapping this out in the future, and switching back to pulse width modulation. I’m not sure if there is any difference in digitalWrite() with a value of HIGH and analogWrite() with a value of 255, maybe someone can shout that out to me @KevinGulling and I’ll make an update here.

I know a lot of you have been following along and that’s great! Show your support by giving a like or retweet, it’s highly appreciated Thanks! Hope you are looking forward to tomorrow, things are starting to get fun aren’t they?

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The post 12 Days of Arduino Day 9 – Robot Core / Cooling System appeared first on Kevin Gulling - Game Development, VR, and more.