OneWheel

[mrburakko]

Variant

USART

Control type

FOC

Control mode

Torque

What can we do to make the firmware better?

Hi. I wanted to build a Onewheel. I didn't find a Onewheel mode so I used UART + MPU6050 (on arduino). Because I'm not a very good programmer in VSC. Has anyone else had this idea? Is there anything I should be careful about?
I configured the right UART because it has a 5V tolerance

`#define HOVER_SERIAL_BAUD 115200
#define SERIAL_BAUD 115200
#define START_FRAME 0xABCD
#define ANGLE_MAX 15

#include <Wire.h>
#include <MPU6050.h>
#include <KalmanFilter.h>
#include <SoftwareSerial.h>

SoftwareSerial HoverSerial(3, 2);
MPU6050 mpu;
KalmanFilter kalmanX(0.001, 0.003, 0.03);
KalmanFilter kalmanY(0.001, 0.003, 0.03);

float accPitch = 0;
float kalPitch = 0;
int kal;
bool buttonState;
bool enable;

typedef struct {
uint16_t start;
int16_t steer;
int16_t speed;
uint16_t checksum;
}

SerialCommand;
SerialCommand Command;

void setup() {
Serial.begin(SERIAL_BAUD);
while (!mpu.begin(MPU6050_SCALE_2000DPS, MPU6050_RANGE_2G)) {
delay(500);
}
HoverSerial.begin(HOVER_SERIAL_BAUD);
pinMode(LED_BUILTIN, OUTPUT);
pinMode(10, INPUT);
}
void Send(int16_t uSteer, int16_t uSpeed) {
Command.start = (uint16_t)START_FRAME;
Command.steer = (int16_t)uSteer;
Command.speed = (int16_t)uSpeed;
Command.checksum = (uint16_t)(Command.start ^ Command.steer ^ Command.speed);
HoverSerial.write((uint8_t *)&Command, sizeof(Command));
}

void loop(void) {

Vector acc = mpu.readNormalizeAccel();
Vector gyr = mpu.readNormalizeGyro();
accPitch = -(atan2(acc.XAxis, sqrt(acc.YAxis * acc.YAxis + acc.ZAxis * acc.ZAxis)) * 180.0) / M_PI;
kalPitch = kalmanY.update(accPitch, gyr.YAxis);
Serial.print(" angle: ");
Serial.print(kalPitch);
if (kalPitch >= ANGLE_MAX) kalPitch = ANGLE_MAX;
if (kalPitch <= -ANGLE_MAX) kalPitch = -ANGLE_MAX;
kal = kalPitch * 5;
Serial.print(" speed: ");
Serial.print(kal);
buttonState = digitalRead(10);
if (buttonState == LOW) {
digitalWrite(LED_BUILTIN, HIGH);
if ((kalPitch < 1) && (kalPitch > -1)) enable = 1;

if (enable == 1) {

  Serial.print(" Motor ");
  Send(0, kalPitch);
}

} else {
digitalWrite(LED_BUILTIN, LOW);
enable = 0;
}
Serial.println();
}`

Pin 10 is footswitch. The engine will only start after the board is level. The maximum angle of the board is 15'. The "mnoznik" is a (angle * mnoznik) = speed. Many values ​​are still to be tuned during testing.

Describe suggestions or alternatives you have considered

I'm waiting for constructive criticism.

[iso14000]

Hi... not sure to anderstand...
did you mean a EUC like that =>https://forum.electricunicycle.org/topic/7056-onewheel-diy-project/

[mrburakko]

Yes ==O==
I've got all the parts. Programmed electronics ect. Frame and drive wheel assembled. All I have left is to build the foot sensor. I don't know what to choose ? Sensor mats ? Capacitive sensor or regular switch ?

[iso14000]

usually , on hoverboard, the passanger detection is build with a elastomer material glued on frame. The material have a small dark piece that cut a optical fork when a passenger put feet on it.n have a look on "side board" for "hoverboard", you will be instructed

[mrburakko]

I understand but I'm wondering about other easier solutions. Pressure-Sensitive Conductive Sheet (Velostat/Linqstat) https://www.adafruit.com/product/1361

[iso14000]

you should be very careful, because it is also security question , any false passager detectiob will lead to unexpected moves...
And a move with speed leads to energy 1/2 mV² and can injure somebody (or your self)
I reckon also on a "double hardware check" design
best regards

[mrburakko]

I was thinking about using two sensors on the one leg. Toes and heel like on original hardware

[nitzerebbs]

Variant

USART

Control type

FOC

Control mode

Torque

What can we do to make the firmware better?

Hi. I wanted to build a Onewheel. I didn't find a Onewheel mode so I used UART + MPU6050 (on arduino). Because I'm not a very good programmer in VSC. Has anyone else had this idea? Is there anything I should be careful about? I configured the right UART because it has a 5V tolerance

`#define HOVER_SERIAL_BAUD 115200 #define SERIAL_BAUD 115200 #define START_FRAME 0xABCD #define ANGLE_MAX 15

#include <Wire.h> #include <MPU6050.h> #include <KalmanFilter.h> #include <SoftwareSerial.h>

SoftwareSerial HoverSerial(3, 2); MPU6050 mpu; KalmanFilter kalmanX(0.001, 0.003, 0.03); KalmanFilter kalmanY(0.001, 0.003, 0.03);

float accPitch = 0; float kalPitch = 0; int kal; bool buttonState; bool enable;

typedef struct { uint16_t start; int16_t steer; int16_t speed; uint16_t checksum; }

SerialCommand; SerialCommand Command;

void setup() { Serial.begin(SERIAL_BAUD); while (!mpu.begin(MPU6050_SCALE_2000DPS, MPU6050_RANGE_2G)) { delay(500); } HoverSerial.begin(HOVER_SERIAL_BAUD); pinMode(LED_BUILTIN, OUTPUT); pinMode(10, INPUT); } void Send(int16_t uSteer, int16_t uSpeed) { Command.start = (uint16_t)START_FRAME; Command.steer = (int16_t)uSteer; Command.speed = (int16_t)uSpeed; Command.checksum = (uint16_t)(Command.start ^ Command.steer ^ Command.speed); HoverSerial.write((uint8_t *)&Command, sizeof(Command)); }

void loop(void) {

Vector acc = mpu.readNormalizeAccel(); Vector gyr = mpu.readNormalizeGyro(); accPitch = -(atan2(acc.XAxis, sqrt(acc.YAxis * acc.YAxis + acc.ZAxis * acc.ZAxis)) * 180.0) / M_PI; kalPitch = kalmanY.update(accPitch, gyr.YAxis); Serial.print(" angle: "); Serial.print(kalPitch); if (kalPitch >= ANGLE_MAX) kalPitch = ANGLE_MAX; if (kalPitch <= -ANGLE_MAX) kalPitch = -ANGLE_MAX; kal = kalPitch * 5; Serial.print(" speed: "); Serial.print(kal); buttonState = digitalRead(10); if (buttonState == LOW) { digitalWrite(LED_BUILTIN, HIGH); if ((kalPitch < 1) && (kalPitch > -1)) enable = 1;

if (enable == 1) {

  Serial.print(" Motor ");
  Send(0, kalPitch);
}

} else { digitalWrite(LED_BUILTIN, LOW); enable = 0; } Serial.println(); }`

Pin 10 is footswitch. The engine will only start after the board is level. The maximum angle of the board is 15'. The "mnoznik" is a (angle * mnoznik) = speed. Many values ​​are still to be tuned during testing.

Describe suggestions or alternatives you have considered

I'm waiting for constructive criticism.

Hi,
which hardware modules did you use ?
can you share a link please?
Thanks a lot