MEGABOBRA: Bosch Smart System Derestriction for Rim Magnet - DIY Project with Support

[Peacepirate]

One question remains:
What do you connect to ELECTROMAGNET_PIN 4?

 

[megabobra]

One question remains:
What do you connect to ELECTROMAGNET_PIN 4?

You can leave that line of code in place and simply make no connection to Pin4.

 

[Striveon]

Have a 2024 Canyon Strive On with Bosch CX race motor rim magnet. Confirming your device will work? Love to have one so much more fun without the cut off.
Thanks

 

[Peacepirate]

You can leave that line of code in place and simply make no connection to Pin4.

Hey there,
when i tried the first time to test your code it didnt worked out but i wanted to check everything before proclaiming that and be sure that this wasnt caused by a wrong edited code. i dont need a variable multiplier but just a fixed value of 2.0 and i dont need a setup mode either so i deleted that part. To exclude these potential sources of errors i uploaded your code again with the changes you talked about:

#define REED_SENSOR_PIN 2
#define SETUP_PIN 6
#define ELECTROMAGNET_PIN 7
#define REDLED_LOWPRESSCOUNT_PIN 5
#define A1A 4
#define A1B 3


byte ButtonState;
byte LastButtonState;
byte Trigger = HIGH;
byte SetupState;

double LastPress = 0;
double CurrentPress = 0;
double EndMagnet = 0;
double MagnetDuration = 0;
double Delta;
double DeltaStatic;
double ActivateMagnetStart = 0;
double ActivateMagnetTemp = 0;
double MultiplierOut = 1;
double MagnetOnTime = 0;
double MultiplierCutOff = 1398; //1398 = 6kph/3.5mph

int Pressed = 0;
int PressCount = 0;
int MagnetSwitch = 0;
int MagnetOn = 0;



////////////////////
//change this MultiplierOut to alter max assistance speed. MultiplierOut 1.4 gives: 25kph * 1.4 = 35kph new max assitance
double MultiplierIn = 2.0;
double SetupDelay = 513;
double SetupWidth = 47;




void setup() {

pinMode(ELECTROMAGNET_PIN, OUTPUT);
pinMode(REED_SENSOR_PIN, INPUT_PULLUP);
pinMode(SETUP_PIN, INPUT_PULLUP);
pinMode(REDLED_LOWPRESSCOUNT_PIN, OUTPUT);
pinMode(A1A, OUTPUT);
pinMode(A1B, OUTPUT);
LastButtonState = digitalRead(REED_SENSOR_PIN);
SetupState = digitalRead(SETUP_PIN);
}

void loop() {

SetupState = digitalRead(SETUP_PIN);
//if we're in setup mode, run the consistent pulsing
if (SetupState == LOW) {
delay(SetupDelay);
//activate coil
digitalWrite(ELECTROMAGNET_PIN, HIGH);
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, HIGH);
digitalWrite(A1A, HIGH);
digitalWrite(A1B, LOW);



delay(SetupWidth); //pulse width
//deactivate coil
digitalWrite(ELECTROMAGNET_PIN, LOW);
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, LOW);
digitalWrite(A1A, LOW);
digitalWrite(A1B, LOW);
}
//outside of setup mode, function as normal
if (SetupState == HIGH) {
ButtonState = digitalRead(REED_SENSOR_PIN);

if ((ButtonState != LastButtonState) && (millis() - CurrentPress > 100)) {
//Button pressed
if (ButtonState == LOW) {
LastPress = CurrentPress;
CurrentPress = millis();
Delta = CurrentPress - LastPress;
Pressed = 2;
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, HIGH);
if ((PressCount < 5) && ((CurrentPress - ActivateMagnetStart >= Delta) || PressCount > 0)) {

digitalWrite(ELECTROMAGNET_PIN, HIGH);
digitalWrite(A1A, HIGH);
digitalWrite(A1B, LOW);
Trigger = HIGH;
ActivateMagnetStart = CurrentPress;
MultiplierOut = MultiplierIn;
MagnetOnTime = millis();
MagnetOn = 1;

}
}
//Button released
if (ButtonState == HIGH) {
EndMagnet = millis();
MagnetDuration = EndMagnet - CurrentPress;
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, LOW);
if (PressCount < 5) {
digitalWrite(ELECTROMAGNET_PIN, LOW);
digitalWrite(A1A, LOW);
digitalWrite(A1B, LOW);
MagnetOn = 0;
}
PressCount = PressCount + 1;
}
LastButtonState = ButtonState;
}
//if travelling slowly, fire coil 1:1
if (millis() - ActivateMagnetStart > MultiplierCutOff) {
PressCount = 0;
}

//If wheel stops on magnet after travelling slowly, turn off the coil after 2seconds
if ((MagnetOn == 1) && (millis() - MagnetOnTime > 2000)) {
digitalWrite(ELECTROMAGNET_PIN, LOW);
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, LOW);
digitalWrite(A1A, LOW);
digitalWrite(A1B, LOW);
}

//Record one Delta to avoid continual changes to interval during multiplied interval below
if ((Trigger == HIGH) && (Delta > 0)) {
DeltaStatic = Delta;
Trigger = LOW;
}

//setup multiplier ramping
if (PressCount >= 5) {
if (PressCount < 10) {
MultiplierOut = (((MultiplierIn - 1) / 5) * (PressCount - 4)) + 1;
} else {
MultiplierOut = MultiplierIn;
}


if (millis() >= ActivateMagnetStart + DeltaStatic * MultiplierOut) {
if ((millis() < ActivateMagnetStart + DeltaStatic * MultiplierOut + MagnetDuration * MultiplierOut) && (Pressed > 0 )) {

//Magnet On
if (MagnetSwitch == 0) {
ActivateMagnetTemp = millis();
}
MagnetSwitch = 1;
digitalWrite(ELECTROMAGNET_PIN, HIGH);
digitalWrite(A1A, HIGH);
digitalWrite(A1B, LOW);
MagnetOnTime = millis();
MagnetOn = 1;

} else {

//Magnet Off
digitalWrite(ELECTROMAGNET_PIN, LOW);
digitalWrite(A1A, LOW);
digitalWrite(A1B, LOW);
ActivateMagnetStart = ActivateMagnetTemp;
Trigger = HIGH;
Pressed = Pressed - 1;
MagnetSwitch = 0;
MagnetOn = 0;
}
}
}
}
}

i tested the L9110 before without an arduino connected to it and could measure with my multimeter either +12v and GND on the motor out pins when i put on GND on A1A or -12v and GND if put gnd on A1B. So the h-bridge works as expected.
When i connect arduino and hbridge together AND DO ANYTHING ELSE after powering on this is the output of l9110:

Tuning device

youtube.com

Here you see voltages of the arduino pins 3/4

 

[megabobra]

Hey there,
when i tried the first time to test your code it didnt worked out but i wanted to check everything before proclaiming that and be sure that this wasnt caused by a wrong edited code. i dont need a variable multiplier but just a fixed value of 2.0 and i dont need a setup mode either so i deleted that part. To exclude these potential sources of errors i uploaded your code again with the changes you talked about:

#define REED_SENSOR_PIN 2
#define SETUP_PIN 6
#define ELECTROMAGNET_PIN 7
#define REDLED_LOWPRESSCOUNT_PIN 5
#define A1A 4
#define A1B 3


byte ButtonState;
byte LastButtonState;
byte Trigger = HIGH;
byte SetupState;

double LastPress = 0;
double CurrentPress = 0;
double EndMagnet = 0;
double MagnetDuration = 0;
double Delta;
double DeltaStatic;
double ActivateMagnetStart = 0;
double ActivateMagnetTemp = 0;
double MultiplierOut = 1;
double MagnetOnTime = 0;
double MultiplierCutOff = 1398; //1398 = 6kph/3.5mph

int Pressed = 0;
int PressCount = 0;
int MagnetSwitch = 0;
int MagnetOn = 0;



////////////////////
//change this MultiplierOut to alter max assistance speed. MultiplierOut 1.4 gives: 25kph * 1.4 = 35kph new max assitance
double MultiplierIn = 2.0;
double SetupDelay = 513;
double SetupWidth = 47;




void setup() {

pinMode(ELECTROMAGNET_PIN, OUTPUT);
pinMode(REED_SENSOR_PIN, INPUT_PULLUP);
pinMode(SETUP_PIN, INPUT_PULLUP);
pinMode(REDLED_LOWPRESSCOUNT_PIN, OUTPUT);
pinMode(A1A, OUTPUT);
pinMode(A1B, OUTPUT);
LastButtonState = digitalRead(REED_SENSOR_PIN);
SetupState = digitalRead(SETUP_PIN);
}

void loop() {

SetupState = digitalRead(SETUP_PIN);
//if we're in setup mode, run the consistent pulsing
if (SetupState == LOW) {
delay(SetupDelay);
//activate coil
digitalWrite(ELECTROMAGNET_PIN, HIGH);
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, HIGH);
digitalWrite(A1A, HIGH);
digitalWrite(A1B, LOW);



delay(SetupWidth); //pulse width
//deactivate coil
digitalWrite(ELECTROMAGNET_PIN, LOW);
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, LOW);
digitalWrite(A1A, LOW);
digitalWrite(A1B, LOW);
}
//outside of setup mode, function as normal
if (SetupState == HIGH) {
ButtonState = digitalRead(REED_SENSOR_PIN);

if ((ButtonState != LastButtonState) && (millis() - CurrentPress > 100)) {
//Button pressed
if (ButtonState == LOW) {
LastPress = CurrentPress;
CurrentPress = millis();
Delta = CurrentPress - LastPress;
Pressed = 2;
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, HIGH);
if ((PressCount < 5) && ((CurrentPress - ActivateMagnetStart >= Delta) || PressCount > 0)) {

digitalWrite(ELECTROMAGNET_PIN, HIGH);
digitalWrite(A1A, HIGH);
digitalWrite(A1B, LOW);
Trigger = HIGH;
ActivateMagnetStart = CurrentPress;
MultiplierOut = MultiplierIn;
MagnetOnTime = millis();
MagnetOn = 1;

}
}
//Button released
if (ButtonState == HIGH) {
EndMagnet = millis();
MagnetDuration = EndMagnet - CurrentPress;
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, LOW);
if (PressCount < 5) {
digitalWrite(ELECTROMAGNET_PIN, LOW);
digitalWrite(A1A, LOW);
digitalWrite(A1B, LOW);
MagnetOn = 0;
}
PressCount = PressCount + 1;
}
LastButtonState = ButtonState;
}
//if travelling slowly, fire coil 1:1
if (millis() - ActivateMagnetStart > MultiplierCutOff) {
PressCount = 0;
}

//If wheel stops on magnet after travelling slowly, turn off the coil after 2seconds
if ((MagnetOn == 1) && (millis() - MagnetOnTime > 2000)) {
digitalWrite(ELECTROMAGNET_PIN, LOW);
digitalWrite(REDLED_LOWPRESSCOUNT_PIN, LOW);
digitalWrite(A1A, LOW);
digitalWrite(A1B, LOW);
}

//Record one Delta to avoid continual changes to interval during multiplied interval below
if ((Trigger == HIGH) && (Delta > 0)) {
DeltaStatic = Delta;
Trigger = LOW;
}

//setup multiplier ramping
if (PressCount >= 5) {
if (PressCount < 10) {
MultiplierOut = (((MultiplierIn - 1) / 5) * (PressCount - 4)) + 1;
} else {
MultiplierOut = MultiplierIn;
}


if (millis() >= ActivateMagnetStart + DeltaStatic * MultiplierOut) {
if ((millis() < ActivateMagnetStart + DeltaStatic * MultiplierOut + MagnetDuration * MultiplierOut) && (Pressed > 0 )) {

//Magnet On
if (MagnetSwitch == 0) {
ActivateMagnetTemp = millis();
}
MagnetSwitch = 1;
digitalWrite(ELECTROMAGNET_PIN, HIGH);
digitalWrite(A1A, HIGH);
digitalWrite(A1B, LOW);
MagnetOnTime = millis();
MagnetOn = 1;

} else {

//Magnet Off
digitalWrite(ELECTROMAGNET_PIN, LOW);
digitalWrite(A1A, LOW);
digitalWrite(A1B, LOW);
ActivateMagnetStart = ActivateMagnetTemp;
Trigger = HIGH;
Pressed = Pressed - 1;
MagnetSwitch = 0;
MagnetOn = 0;
}
}
}
}
}

i tested the L9110 before without an arduino connected to it and could measure with my multimeter either +12v and GND on the motor out pins when i put on GND on A1A or -12v and GND if put gnd on A1B. So the h-bridge works as expected.
When i connect arduino and hbridge together AND DO ANYTHING ELSE after powering on this is the output of l9110:

Tuning device

youtube.com

Here you see voltages of the arduino pins 3/4 View attachment 141256





View attachment 141257

Let me post back later with a photo of the wiring from my spare bench setup so you can compare against your own. At best for now, all I have is a photo below of my current unit that's presently tucked away in the bike, but you can't see much of the L9110 in it!

Your connections should be:
Arduino 3 > L9110 motor A Input 1
Arduino 4 > L9110 motor A Input 2
Arduino Ground > L9110 Ground
Source 12v > L9110 positive input

Then you should be able to measure plus (or minus, depending on the motor's output direction) twelve volts across motor A outputs on the L9110. Just for fun, you can set the motor speed using: analogWrite(A1A, 255); where the A1A corresponds to whichever you selected as the HIGH output, and the speed ranges from 0 (stopped) to 255 (full speed). eg analogWrite(A1A, 127); should give you half speed, or 6v at the motor output.

Your code looks fine, though you mentioned you don't need setup mode yet setup mode is still in the code. Without knowing what the default state of that setup pin is with no connection, you might find you're entering setup mode anyway?

 

[megabobra]

Some additional photos of my test setup as promised:

connections to the L9110s:

Connections to the arduino to pins 7 and 8 per the code. Note that I'm simply using the 3.3v output in this case since this test unit is always powered by USB. In the unit in the bike, it's using the 5v output direct from the voltage regulator.

 

[Peacepirate]

ok, once again.
Here we see that without arduino the voltage output of the h bridge switches between +12v and -12v - depending on whether gnd is on the left pin or the right pin. So if digispark switches to low (gnd) on pin 3 there should be 12v And if pin4 is on gnd there should be -12v.

We see in the video there is no stable voltage output but i varies. I believe that inside your setup mode you switch off/on automatically so its possible i am by default in this mode. How can i switch that mode off completly by code?

 

[Peacepirate]

Now i am checking voltage on pin3 and 4.
digispark gets 12v
The red measuring tip of my Multimeter is on 12v directly and the black tip measures on pin4:
The voltage varies between 10,85v and 11,77 on pin4. .
When i measure pin3 (black tip in pin3 & red tip on 12v) i see constant and stable 11,67v.
I understand that if i see 11,67v on the multimeter the arduino has switched to low on pin3 and that means gnd is on pin3.

 

[Peacepirate]

I changed the code in line 56 from
SetupState = digitalRead(SETUP_PIN)
to
SetupState = HIGH
in order to deactivate setup mode. Hopefully i understood that correctly.

Now when i power on digispark and measure voltage on yellow / green (output_pins 3 /4) (red tip 12v / black tip pin3 or 4) i see quiete stable 11,67v on my multimeter.





This means Digispark switched both pins to LOW (GND).

When i connect both pins to L9110 h bridge i see very stable 0,215 voltage difference between motor output 1 and 2.


This seems to be more plausible because there shouldnt be any voltage changes on l9110 motor output if nothing has happened.
Now i am taking a magnet and use it to trigger the reed sensor once. Look at the video attached here.

29. Mai 2024

youtube.com

All over sudden it seems as arduino starts to switch around those two pins permanently and i believe it should switch only once if it gets only one input signal shouldnt it? Instead this show is taking place. Goddamit…

I just checked what causes this behaviour after triggering reed sensor once and measured voltage on pin 3 and pin 4 in relation to 12v.
pin4 (green) is stable and doesnt change its gnd level (11,67v).
Yellow(pin3) is freaking around for some reason. Maybe i flash another digispark in case digispark is malfunctioning.

 

[Peacepirate]

I took a new digispark and instead of the multimeter i connected an emagnet to the h bridge. I cannot distuinguish whether the small two pins are pulled and pushed away continously because the h bridge switches the polarity and thus creates a positive and a negative magnetic field but i believe this is the case. In contrast to your first build with only one magnetic pole i believe that the two pins are being really pushed away actively by the changing magnetic field. But the code is not working correctly at all because one input pin impuls results in endless output impulses and endless switching.
Here a link:

29. Mai 2024

youtube.com