Hi boys & girls,
I've picked up a side-project, where I would connect an Arduino Nano (with a HC-05 module) to an e-scooter. The software works as far of reading out the scooter (through the Throttle wire) and setting the Throttle when needed.
Now the next step is to connect to the Bluetooth Module, however this seems to give some strange results. Forgive me, but I am new to Arduino, so I don't exactly understand all the components. Somehow my existing code interferes with the new loop that I create, so it only executes once.
My existing code (with the created BluetoothSerial).
#include <Arduino.h>
#include <arduino-timer.h>
#include <SoftwareSerial.h>
//SETTINGS
//===========================================================================
//=============================Select model ================================
//===========================================================================
//
// 0 = Xiaomi Mi Scooter Essential
// 1 = Xiaomi Mi Scooter 1S (Not tested)
// 2 = Xiaomi Mi Scooter Pro 2
#define SCOOTERTYPE 2
//===========================================================================
//=============================Motion behavior =============================
//===========================================================================
// Boost timer, how long the motor will be powered after a kick. time in miliseconds.
int boosttimer = 8000;
int kickdelay = 1000; //time before you can do an new kick after boost timer is expired.
// Smooth readings of the speedometer. The higher the number, the more the readings
// will be smoothed, but the slower the step will respond to the kicks.
const int speedReadings = 20;
//===========================================================================
//============================= Pin Settings =============================
//===========================================================================
// Arduino pin where throttle is connected to (only pin 9 & 10 is ok to use)
const int THROTTLE_PIN = 10;
//TX & RX pin
SoftwareSerial SoftSerial(2, 3);
SoftwareSerial bluetoothSerial(12, 11); // RX, TX for Bluetooth
//END OF SETTINGS
auto timer_m = timer_create_default();
int BrakeHandle;
int Speed; //current speed
int oldspeed; //speed during last loop
int trend = 0; //speed trend
int readings[speedReadings]; // the readings from the speedometer
int readIndex = 0; // the index of the current reading
int total = 0; // the running total
int AverageSpeed = 0; // the average speed over last X readings
int OldAverageSpeed = 0; // the average speed over last X readings in the last loop
char bluetoothInput;
//motionmodes
uint8_t motionstate = 0;
#define motionready 0
#define motionbusy 1
#define motionbreaking 2
void logByteInHex(uint8_t val)
{
// if(val < 16)
// Serial.print('0');
//
// Serial.print(val, 16);
// Serial.print(' ');
}
uint8_t readBlocking()
{
while (!SoftSerial.available()) {
delay(1);
}
return SoftSerial.read();
}
void setup()
{
// initialize all the readings to 0:
for (int thisReading = 0; thisReading < speedReadings; thisReading++) {
readings[thisReading] = 0;
}
bluetoothSerial.begin(9600);
Serial.begin(115200);
SoftSerial.begin(115200);
Serial.println("Starting Logging data...");
TCCR1B = TCCR1B & 0b11111001; //Set PWM of PIN 9 & 10 to 32 khz
ThrottleWrite(45);
}
uint8_t buff[256];
void loop()
{
int w = 0;
while (readBlocking() != 0x55);
if (readBlocking() != 0xAA)
return;
uint8_t len = readBlocking();
buff[0] = len;
if (len > 254)
return;
uint8_t addr = readBlocking();
buff[1] = addr;
uint16_t sum = len + addr;
for (int i = 0; i < len; i++)
{
uint8_t curr = readBlocking();
buff[i + 2] = curr;
sum += curr;
}
uint16_t checksum = (uint16_t)readBlocking() | ((uint16_t)readBlocking() << 8);
if (checksum != (sum ^ 0xFFFF))
return;
for (int i = 0; i < len + 2; i++)
logByteInHex(buff[i]);
// Serial.print("check ");
// Serial.print(checksum, 16);
//
// Serial.println();
switch (buff[1]) {
case 0x20:
switch (buff[2]) {
case 0x65:
BrakeHandle = buff[6];
}
case 0x21:
switch (buff[2]) {
case 0x64:
if (buff[8] != 0) {
Speed = buff[8];
}
}
}
// subtract the last reading:
total = total - readings[readIndex];
// read from the speedometer:
readings[readIndex] = Speed;
// add the reading to the total:
total = total + readings[readIndex];
// advance to the next position in the array:
readIndex = readIndex + 1;
// if we're at the end of the array...
if (readIndex >= speedReadings) {
// ...wrap around to the beginning:
readIndex = 0;
}
// calculate the average:
AverageSpeed = total / speedReadings;
Serial.print("Speed: ");
Serial.print(AverageSpeed);
Serial.print(" Brake: ");
Serial.print(BrakeHandle);
Serial.print(" State: ");
Serial.print(motionstate);
Serial.println(" ");
motion_control();
timer_m.tick();
}
bool release_throttle(void *) {
Serial.println("Timer expired, stopping...");
#if (SCOOTERTYPE==0)
ThrottleWrite(80); //Keep throttle open for 10% to disable KERS. best for essential.
#elif (SCOOTERTYPE==1) || (SCOOTERTYPE==2)
ThrottleWrite(45); //Close throttle. best for pro 2 & 1S.
#endif
timer_m.in(kickdelay, motion_wait);
return false; // false to stop
}
bool motion_wait(void *) {
Serial.println("Ready for new kick!");
motionstate = motionready;
return false; // false to stop
}
void motion_control() {
if ((Speed != 0) && (Speed < 5)) {
// If speed is under 5 km/h, stop throttle
ThrottleWrite(45); // 0% throttle
}
if (BrakeHandle > 47) {
ThrottleWrite(45); //close throttle directly when break is touched. 0% throttle
Serial.println("BRAKE detected!!!");
motionstate = motionready;
timer_m.cancel();
}
if (Speed != 0) {
// Check if auto throttle is off and speed is increasing
if (motionstate == motionready) {
trend = AverageSpeed - OldAverageSpeed;
if (trend > 0)
{
// speed is increasing
// Check if speed is at least 5 km/h
if (AverageSpeed > 5) {
// Open throttle for 5 seconds
AnalyseKick();
Serial.println("Kick detected!");
timer_m.in(boosttimer, release_throttle); //Set timer to release throttle
motionstate = motionbusy;
}
}
else if (trend < 0)
{
// speed is decreasing
}
else
{
// no change in speed
}
}
oldspeed = Speed;
OldAverageSpeed = AverageSpeed;
}
}
void AnalyseKick() {
if (AverageSpeed < 10) {
ThrottleWrite(140); // 40% throttle
}
else if ((AverageSpeed >= 10) & (AverageSpeed < 14)) {
ThrottleWrite(190); // 80% throttle
} else {
ThrottleWrite(233); // 100% throttle
}
}
int ThrottleWrite(int value)
{
if (value != 0) {
analogWrite(THROTTLE_PIN, value);
}
}
When I add a while loop inside the loop from Arduino, I only receive my input once (short when I connect to the module serial bus). I've tracked it down to the following code that is blocking my Bluetooth Serial:
while (readBlocking() != 0x55);
if (readBlocking() != 0xAA)
return;
When I comment this part out the Bluetooth module starts receiving messages that I can print back to the phone it is connected to. But when I uncomment the code above, this happens only once and my speed readings don't come through anymore.
Port D10 is connected to my scooter and port D11 & D12 are connected to my Bluetooth Module.
I know many of you said, watch out when you use 115200 and SoftwareSerial, it's a recipe for disaster, but somehow I don't get it to work without using it.
I was hoping that some of you might give me some tips on how to proceed. Once again, I am a Software Engineer, but this is my first "real" attempt at doing something with hardware. I hope you could help me.
Kind regards,
- N