13. Output devices | DC-Motor controller

- Measure the power consumption of an output device. Document your work (in a group or individually):

Group assignment page: here.

My individual part:
I have documented it in the Power consumption measurement section.

- Add an output device to a microcontroller board you’ve designed and program it to do something:

Since for my final project, the only output I need are motors, then I worked on that during this assignment, using a 12V DC motor.

First I tried it with a L298N commercial driver board and the microcontroller board that I design during the Electronics design assignment.

Eventually, I designed a board based on the L298N driver chip + an ATtiny1614 Microcontroller chip; this board is made to control only one motor, serving as a first test and experience my for final-project board.

On both tests I used the USB and UPDI adapter boards that I made during the Electronics production assignment.

Power consumption measurement

Since we had to measure the power consumption of an output device for this assignment, besides checking the datasheet of it, I used a power supply and a multimeter for this task; I have done the rest with a 9V battery, since my final project is going to work with batteries.

Voltage measurement (V)

I applied the voltage according to datasheet. (It is a 12V DC-motor)

This is done in parallel to the device:

Well, the result are the 12V applied. 🤷🏽‍♂️

Current measurement (I)

This is done in series to the device:

Result: 114.5mA.

Power consumption (P) = V*I = 12V * 114.5mA = 1.37W

Datasheet information

In addition, I compared the values from the datasheet of the motor (a JGA25-370):

The measured No-load electric current is 14.5mA higher than that from the datasheet.

First test

Circuit

Components

Qty	Description
1	MyMiniBoard_X14
1	USB FTDI board
1	FTDI-UPDI adapter board
1	L298N driver
1	12V DC motor
1	9V alkaline battery
a few	jumper cables

Physical circuit

Code

1DC_Motor_Test1:

/* Made by Jefferson Sandoval during the Output devices for the FabAcademy2021
 *  
 * This is just a simple testing code in Arduino for learning how to control a DC motor with 
 * a L298N driver.
 * The code runs the motor: ClockWise for 2secs and turns it off for 0.2secs, then CounterClockWise 
 * for 2secs and turns it off for 0.2secs.
 * 
 * This code was uploaded to a board with an Attiny1614 microcontroller. Documentation:
 * http://fabacademy.org/2021/labs/kamplintfort/students/jefferson-sandoval/assignments/week13/
 */

const int motorPin1 = 1;
const int motorPin2 = 0;
int speed = 200;

void setup(){
//Set pins as outputs
pinMode(motorPin1, OUTPUT);
pinMode(motorPin2, OUTPUT);
}

void loop(){
//Control Motor A in both directions

analogWrite(motorPin1, speed);
analogWrite(motorPin2, 0);
delay(2000);

analogWrite(motorPin1, 0);
analogWrite(motorPin2, 0);
delay(200);

analogWrite(motorPin2, speed);
analogWrite(motorPin1, 0);
delay(2000);

analogWrite(motorPin1, 0);
analogWrite(motorPin2, 0);
delay(200);
}

Performance

Video1: Test with a commercial L298 driver and my MyMiniBoard_X14

Making my L298N controller board

Now the idea is to make a first testing board that contains a microcontroller (an ATtiny1614 in this case), and a motor driver (a L298N in this case) together.

Since it’s just a testing board I didn’t add any voltage regulator, I take the 5V from my laptop.

Schematics

Board layout

Milling PCB

The milling machine I used was the Roland MonoFab SRM-20.
The tool I used was a V-bit 0.2-0.5mm.

Images:
* Traces:

• Holes:
  

• Outlines:
  

Milled PCB:

Components for the board:

Qty	Description
1	L298N driver
1	ATtiny1614
4	1N4007-SMD diodes
1	100nF capacitor
1	220uF 35V capacitor
1	499Ohms resistor
1	Yellow LED
9	Single row right-angle male pin header
2	Screw terminal 1x2

Result

Testing board

Connection

Components

Qty	Description
1	USB FTDI board
1	FTDI-UPDI adapter board
1	My L298N controller board
1	12V DC motor
1	9V alkaline battery
a few	jumper cables

I also used a “charger doctor” which is a USB voltmeter and ammeter device so I can find out quickly if something is going wrong even before it could you know… burn! 🔥

Physical circuit

Code

1DC_Motor_Test2:

/* Made by Jefferson Sandoval during the Output devices for the FabAcademy2021
 *  
 * This is just a simple testing code in Arduino for learning how to control a DC motor with 
 * a L298N driver.
 * The code runs the motor using PWM from 50 to 250 on both directions: ClockWise rotation, stops 
 * for 0.5 secs; then CounterClockWise rotation, stops for 0.5secs.
 * 
 * This code was uploaded to a board with an Attiny1614 microcontroller. Documentation:
 * http://fabacademy.org/2021/labs/kamplintfort/students/jefferson-sandoval/assignments/week13/
 */

//Motor A
const int motorPin1 = 0;
const int motorPin2 = 1;
const int Enable = 2;
int speed;

void setup(){
//Set pins as outputs
pinMode(motorPin1, OUTPUT);
pinMode(motorPin2, OUTPUT);
pinMode(Enable, OUTPUT);
digitalWrite(Enable, 1);
}

void loop(){
//Control Motor A in both directions
for (speed=50; speed<=250; speed++){
analogWrite(motorPin1, speed);
analogWrite(motorPin2, 0);
delay(50);}

analogWrite(motorPin1, 0);
analogWrite(motorPin2, 0);
delay(500);

for (speed=50; speed<=250; speed++){
analogWrite(motorPin2, speed);
analogWrite(motorPin1, 0);
delay(50);}

analogWrite(motorPin1, 0);
analogWrite(motorPin2, 0);
delay(500);
}

Performance

Video2: PWM test with L298 driver ATtiny1614 on board

Assignment outlook

For the official board for my final project, I’ll be making just a motor driver (also probably with a chip different than the L298N), one that doesn’t need external diodes 😅. I would like to make a board without microcontroller so I (or someone else) could use it on another projects with their own boards or even with commercial ones; it’s also a good practice using boards for logical and power circuits separated.

I also think bout making microcontroller board in such a way that I don’t need cables to connect it to the driver.

Files and references

- 1DC_Motor_Test.ino
- 1DC_Motor_Test2.ino
- KiCad project: OneMotorDriverL298.zip

Support documentation
- HowToMechatronics. DC motor control

Datasheets
- L298
- JGA25-370 geared motor

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Last update: June 5, 2021