How to Build an Arduino Self Balancing Robot. By Roland Pelayo. Ever wonder how Segways work This tutorial will show you how to build an Arduino self balancing robot that balances itself just like a Segway How Does Balancing Work To keep the robot balanced, the motors must counteract the fall of the robot. This action requires a feedback and a correcting element. The feedback element is the MPU6. MPU6. 05. 0 I2. C basics which is used by the Arduino to know the current orientation of the robot. The correcting element is the motor and wheel combination. Required Materials. Arduino UNO or Nano can be used. I used Nano for this project. MPU6. Previous Post An easy to follow guide to making a bootable Windows 7 thumb drive for installing on a netbook. Next Post Arduino 3. Volt LiPo Battery Meter. IMPORTANT Note 3122015 the IRRemote library will not work with newer versions of the Arduino program I had to download version 1. There are lots of examples on the internet on how to program an Arduino as an I 2 C master to communicate with I 2 C slave devices. There are, however, very few. This time I will be showing you how to make a module for letting the Arduino find out the time. Although there are many tutorials for the Real Time Clock module I. This is a sixteen bit ADC that will greater improve your Arduino Measurement Resolution. Includes a pin outs, tutorial and sketch. I recently purchased a Arduino DeadOn RTC DS3234 breakout board. Initially i was planning to use this as a more accurate. L2. 98. N driver module. Geared DC Motorwheels. Three platforms PCB, acrylic, or thick plasticPosts to hold the platforms. Wire.H Arduino Library Download' title='Wire.H Arduino Library Download' />Jumper wires. Headers. Battery Pack. Connection Diagram. Complete Fritzing diagram. Connect the MPU6. Arduino first and test the connection using the codes in this IMU interfacing tutorial. If data is now displayed on the serial monitor, youre good to go Proceed to connect the rest of the components as shown above. INA219-Arduino-Tutorial-Hook-Up.png?resize=576%2C828' alt='Wire.H Arduino Library Download' title='Wire.H Arduino Library Download' />You need to download another Library to get the Arduino to talk with the DHT11 sensor. The sensor I got didnt come with any documentation, so I Googled around until. Introduction. Welcome to the LCD Library for Arduino and Chipkit. It is a derivate of the original LiquidCrystal Library as sourced in the Arduino SDK. Nice sensor. Here is an Arduino Sketch that lights it up Adapted from Pololus Board Since I use 45 for signal, the next pins 23 can be used for power. The MPU6050 is a serious little piece of motion processing tech By combining a MEMS 3axis gyroscope and a 3axis accelerometer on the same silicon die t. The L2. 98. N module can provide the 5. V needed by the Arduino as long as its input voltage is 7 V or greater. However, I chose to have separate power sources for the motor and the circuit for isolation. Note that if you are planning to use a supply voltage of more than 1. V for the L2. 98. N module, you need to remove the jumper just above the 1. V input. Building the Robot. Robot frame made mostly of acrylic slab with two geared dc motors. Main circuit board consisting of an Arduino Nano and MPU6. L2. 98. N motor driver module. Geared DC motor with wheel. The self balancing robot is essentially an inverted pendulum. It can be balanced better if the center of mass is higher relative to the wheel axles. A higher center of mass means a higher mass moment of inertia which corresponds to lower angular acceleration slower fall. This is why Ive placed the battery pack on top. The height of the robot, however, was chosen based on the availability of materials. Completed self balancing robot. At the top are six Ni Cd batteries for powering the circuit board. In between the motors is a 9. V battery for the motor driver. More Self balancing Theories. In control theory, keeping some variable in this case, the position of the robot steady needs a special controller called a PID P for proportional, I for integral, and D for derivative. Each of these parameters has gains normally called Kp, Ki, and Kd. PID provides correction between the desired value or input and the actual value or output. The difference between the input and the output is called error. The PID controller reduces the error to the smallest value possible by continually adjusting the output. In our Arduino self balancing robot, the input which is the desired tilt, in degrees is set by software. The MPU6. 05. 0 reads the current tilt of the robot and feeds it to the PID algorithm which performs calculations to control the motor and keep the robot in the upright position. PID requires that the gains Kp, Ki, and Kd values be tuned to optimal values. Engineers use software like MATLAB to compute these values automatically. Unfortunately, we cant use MATLAB in our case because it would further complicate the project. We will tune the PID values manually instead. Ive outlined the steps on how to do this Make Kp, Ki, and Kd equal to zero. Adjust Kp. Too little Kp will make the robot fall over not enough correction. Too much Kp will make the robot go back and forth wildly. A good enough Kp will make the robot slightly go back and forth or oscillate a little. Once the Kp is set, adjust Kd. A good Kd value will lessen the oscillations until the robot is almost steady. Also, the right amount of Kd will keep the robot standing even if pushed. Lastly, set the Ki. The robot will oscillate when turned on even if the Kp and Kd are set but will stabilize in time. The correct Ki value will shorten the time it takes for the robot to stabilize. Arduino Self balancing Robot Code. I needed four external libraries to make this Arduino self balancing robot work. The PID library makes it easy to calculate the P, I, and D values. The LMotor. Controller library is used for driving the two motors with the L2. N module. The I2. Cdev library and MPU6. AxisMotion. Apps. MPU6. 05. 0. You can download the code including the libraries in this repository. PIDv. LMotor. Controller. I2. Cdev. h. include MPU6. AxisMotion. Apps. I2. CDEVIMPLEMENTATION I2. CDEVARDUINOWIRE. Wire. MINABSSPEED 2. MPU controlstatus vars. Ready false set true if DMP init was successful. Int. Status holds actual interrupt status byte from MPU. Status return status after each device operation 0 success, Size expected DMP packet size default is 4. Count count of all bytes currently in FIFO. Buffer6. 4 FIFO storage buffer. Quaternion q w, x, y, z quaternion container. Vector. Float gravity x, y, z gravity vector. Setpoint 1. 73. Setpoint. Angle. Offset 0. Kp 5. Kd 1. Ki 6. 0. PID pid input, output, setpoint, Kp, Ki, Kd, DIRECT. Speed. Factor. Left 0. Speed. Factor. Right 0. MOTOR CONTROLLER. LMotor. Controller motor. ControllerENA, IN1, IN2, ENB, IN3, IN4, motor. Speed. Factor. Left, motor. Speed. Factor. Right. Interrupt false indicates whether MPU interrupt pin has gone high. Data. Ready. mpu. Interrupt true. I2. C bus I2. Cdev library doesnt do this automatically. I2. CDEVIMPLEMENTATION I2. CDEVARDUINOWIRE. TWBR 2. Hz I2. C clock 2. Hz if CPU is 8. MHz. I2. CDEVIMPLEMENTATION I2. CDEVBUILTINFASTWIRE. Fastwire setup4. Status mpu. Initialize. supply your own gyro offsets here, scaled for min sensitivity. XGyro. Offset2. 20. YGyro. Offset7. 6. ZGyro. Offset 8. ZAccel. Offset1. Status 0. DMP, now that its ready. DMPEnabledtrue. Arduino interrupt detection. Interrupt0, dmp. Data. Ready, RISING. Int. Status mpu. Int. Status. DMP Ready flag so the main loop function knows its okay to use it. Ready true. get expected DMP packet size for later comparison. Size mpu. dmp. Get. FIFOPacket. Size. Set. ModeAUTOMATIC. Set. Sample. Time1. Set. Output. Limits 2. DMP configuration updates failed. Serial. printFDMP Initialization failed code. Serial. printdev. Status. Serial. printlnF. Ready return. wait for MPU interrupt or extra packets available. Interrupt fifo. Count lt packet. Size. no mpu data performing PID calculations and output to motors. Compute. motor. Controller. MINABSSPEED. INTSTATUS byte. Interrupt false. Int. Status mpu. Int. Status. FIFO count. Count mpu. FIFOCount. check for overflow this should never happen unless our code is too inefficient. Int. Status 0x. Count 1. FIFO. Serial. printlnFFIFO overflow. DMP data ready interrupt this should happen frequently. Int. Status 0x. VERY short wait. Count lt packet. Size fifo. Count mpu. FIFOCount. FIFO. FIFOBytesfifo. Buffer, packet. Size. Download Serenade Software Microwave Free. FIFO count here in case there is 1 packet available. Count packet. Size. Get. Quaternion q, fifo. Buffer. mpu. dmp. Get. Gravity gravity, q. Get. Yaw. Pitch. Rollypr, q, gravity. Arduino Dead. On RTC DS3. I recently purchased a Arduino Dead. On RTC  DS3. 23. 4 breakout board. Initially i was planning to use this as a more accurate replacement for a DS1. DS1. 30. 7 uses I2. C whilst the DS3. SPI. This blog post is written to hopefully help others avoid  wasting an hour or so learning about this chip and how to get it working quickly and easily  with an Arduino DiecimilaDuemilanoveUno. In basic terms the I2. C only uses 2 conenctions Clock, Data to communicate over the analog input pin 3 and 4 Arduino help. In contrast the SPI uses 4 connections to communicate SS pin 1. MOSI pin 1. 1, MISO pin. SCK Pin. 13. Read more at Arduino help. Now we have a short introduction done lets get to the wiring image and getting the sample code from sparkfun to run You may notice that SS isnt connected to 1. SPI documentation stated, this is because sparkfuns example defines pin 8 as part of the sample, you may also notice that there is an additional pin SQW connected to GND, This is to allow the use of the RTC Libary that we will cover later on in the post. First here is the first code snippet of the sparkfun example include lt SPI. Serial. begin9. 60. Set. Time. Date1. Serial. printlnRead. Time. Date. RTCinit. Modecs,OUTPUT chip select. SPI library. SPI. SPI. set. Bit. OrderMSBFIRST. SPI. set. Data. ModeSPIMODE1 both mode 1 3 should work. Writecs, LOW. SPI. E. SPI. transfer0x. Osciallator and Battery SQ wave 1hz, temp compensation, Alarms disabled. Writecs, HIGH. Set. Time. Dateint d, int mo, int y, int h, int mi, int s. Time. Date 7s,mi,h,0,d,mo,y. Time. Datei1. 0. Time. Datei b1. B0. 00. B0. 00. 00. 00. 1. Time. Datei ablt lt 4. Writecs, LOW. SPI. SPI. transferTime. Datei. digital. Writecs, HIGH. String Read. Time. Date. int Time. Date 7 second,minute,hour,null,day,month,year. Writecs, LOW. SPI. SPI. transfer0x. Writecs, HIGH. B0. B0. 01. 10. 00. B0. 00. 00. 01. 0. B0. 00. 00. 00. 1. Time. Dateiab. B0. Time. Dateiab. B0. Time. Dateiab. B1. Time. Dateiab. B0. Time. Dateiab. Time. Date4. temp. Time. Date5. temp. Time. Date6. temp. Time. Date2. temp. Time. Date1. temp. Time. Date0. returntemp. Once uploaded keep the Arduino program open, and go to Tools Serial Monitor, ensure the baud down the bottom right is set to 9. You should see an output like And so on, The code sets the time to 1. So success, if you have got this far your doing well. But lets get something that would be a little more use to us in our programs. Thankfully a user manicbug made a mod to the standard RTC library As used with 1. DS1. 30. 7. You can jump onto the github service and download a. Im writing this tutorial with so it should work here. Extract the folder inside the zip into your arduinolibraries and rename the folder to Manicbug. RTCLib, If you already have the generic RTClib installed it is best to move it out of the libraries folderOtherwise it could call the original RTCLIB. Restart the Arduino software. With a new sketch paste in the following code, Alternatively you can go file examples   Manicbug. RTCLib DS3. Date and time functions using a DS1. RTC connected via I2. C and Wire lib. include lt SPI. Wire. h. include lt RTClib. RTCDS3. 23. 4. h. Avoid spurious warnings. PROGMEM attribute section. PSTRs extensionstatic progchar c PROGMEM s c0. Create an RTC instance, using the chip select pin its connected to. RTCDS3. 23. 4 RTC8. Serial. begin5. 76. Serial. printlnRTClibexamplesds. SPI. begin. RTC. RTC. Serial. printlnRTC is NOT running. Serial. printSetting time to. Serial. printDATE. Serial. print. Serial. TIME. RTC to the date time this sketch was compiled. RTC. adjustDate. TimeDATE, TIME. Date. Time now RTC. Serial. printlnnow. Stringbuf,len. Serial. Serial. printnow. Serial. prints. Serial. L. Serial. printlnd. Date. Time future now. L 3. 0. Serial. Serial. Stringbuf,len. Serial. Once uploaded keep the Arduino program open, and go to Tools Serial Monitor, ensure the baud down the bottom right is set to 5. You should see an output like You will notice that the time is now formatted correctly, still as 1. This is because the RTC has continued to run since your last program, The easiest way to fix this is to unplug the Arduino pop the battery out of the RTC wait 5 seconds then put the battery back in and connect the Arduino and compile upload the program again quickly if you want it super accurate. This will set the time to the same time as the sketch was compiled and uploaded, from here it should continue on and keep time. Unfortunately after all this the SPI of the DC3. I Hope this tutorial helps someone out there, let me know how you go and what you think. Im no expert with this, but Im happy to stumble through and help.