Trinket / ESC / Coding issue (Deadline tomorrow!)

This project is for the Outlaw devision of Pinewood Derby. There is a turbine fan on the car that will accelerate to full power when the IR is broken. Then it will stop after 2 full seconds and will not re-arm until board is reset.

I have a 5v trinket with a ESC hooked up. The code is pasted below. The problem I have is that the ESC just stays in program mode. I will not have a throttle on this project (nor do I have one) so I can't set the settings. I need the arduino programming to tell the ESC to get out of programming mode.

#include <Adafruit_SoftServo.h>

volatile uint8_t counter = 0;
unsigned long stagedTime = 0;
unsigned long racingTime = 0;

Adafruit_SoftServo esc;

#define SERVOPIN  0                         // Servo control output pin
#define LEDPIN    1                         // LED output pin
#define IRBEAMPIN 2                         // IR beam input pin

#define OFFSPEED    0                       // Lowest ESC speed (range 0-180)
#define STAGEDSPEED 25                      // ESC speed when staged before race start
#define RACINGSPEED 180                     // Maximum ESC speed when race start detected 

#define MINIMUMSTAGEDDURATION 2000          // Minimum duration car must be stage to enter race mode in milliseconds
#define MAXIMUMRACEDURATION 1500            // Maximum duration of racing speed in milliseconds

enum raceState {
  DONE                                      // Do not allow motor to turn back on after race until power reset
raceState currentState = OFF;

void setup() {
  // ESC
  pinMode(SERVOPIN, OUTPUT);                // Set up ESC control pin as an output
  esc.attach(SERVOPIN);                     // Attach the pin to the software servo library
  // LED
  pinMode(LEDPIN, OUTPUT);                  // Set Trinket pin 1 as an output for LED
  // IR BEAM
  pinMode(IRBEAMPIN, INPUT);                // Set up IR beam pin as input
  digitalWrite(IRBEAMPIN, HIGH);            // Enable then internal pull up resistor
  // Interupt Registers
  OCR0A = 0xAF;                             // Set up a 2ms interrupt

void loop() {
  // Use the IR beam sensor to determine the current state of the race
  if (digitalRead(IRBEAMPIN) == HIGH)       // IR beam NOT broken
    if (currentState == STAGED) {           // If car is currently staged
      // If car has been staged for longer than the staged duration
      if ((millis() - stagedTime) > MINIMUMSTAGEDDURATION) {
        racingTime = millis();              // Start race duration timer
        currentState = RACING;              // ENTER RACE MODE
        currentState = OFF;                 // Off mode
  else {                                    // IR beam BROKEN
    if (currentState == OFF) {
      stagedTime = millis();                // Start "Staged" timer
      currentState = STAGED;                // CAR IS STAGED

  // Turn off the motor after a specified race duration
  if (currentState == RACING) {             // If the car is currently racing
    // Measure the race duration and compare it to maximum race duration
    if ((millis() - racingTime) > MAXIMUMRACEDURATION) {
      currentState = DONE;                  // Turn ESC off
  // Set the ESC speed depending on the current state
  if (currentState == STAGED) {
    digitalWrite(LEDPIN, HIGH);             // Turn ON LED
  else if (currentState == RACING)
  else {
    digitalWrite(LEDPIN, LOW);              // Turn OFF LED

// The SIGNAL(TIMER0_COMPA_vect) function is the interrupt that will be called by the microcontroller every 2 milliseconds
  counter += 2;                             // Add two milliseconds to the elapsed time
  if (counter >= 20) {                      // Has 20ms elapsed?
    counter = 0;                            // Reset the timer
    esc.refresh();                          // Refesh the software based servo control

Have a look at the controller and find out what input signal it needs to get into normal operation - and reproduce that in your sketch .
That will almost certainly need a throttle input to the esc , see it’s spec .

It’s tomorrow...

Yeah, I wasn't able to get it to work in time. We suspect the ESC is malfunctioning though. I tried to set the signal input to low (normal operation mode) and that didnt work. I'm going to order some different parts, including a throttle kit to configure the ESC and try again for next years race. It will give me more time to tune it.

I appreciate the help though!

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