Need help with Arduino code for servo direction, please

MIT App Inventor Help
1

I'm trying to get servos to point 0, 90, and 180 degrees with MIT app inventor.
So the MIT app connects with to my Adafruit ESP32 V2 feather which has the 8 channel PWM servo wing, and they move.
As a newbie, I'm trying to adapt the example code for just 2 of the 8 servos but since I don't fully understand, they are not pointing correctly.
I need help with the Arduino code to receive the MIT text like B01, N01, and F01. So B will turn the servo fully clockwise, N would turn 90 and F would turn it fully counterclockwise. 00 to 07 would be the servos.
This is a copy of my Arduino code. Note that it currently receives number 1 to 6 but it will need to use my B01 (or I could use 1 for 0, 2 for 90, and 3 for 180. So 204 would turn servo number 5 to 90 degrees) if that technique makes it easier.
I'm just so frustrated, again.

#include <Wire.h>
#include <Adafruit_PWMServoDriver.h>
#include <BluetoothSerial.h>

BluetoothSerial SerialBT;

Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();

#define SERVOMIN  150
#define SERVOMAX  600
#define USMIN  600
#define USMAX  2400
#define SERVO_FREQ 50

uint8_t servonum = 0;

void setup() {
  SerialBT.begin("Esp32-BT");
  pwm.begin();
  pwm.setOscillatorFrequency(27000000);
  pwm.setPWMFreq(SERVO_FREQ);
  delay(10);
}

void setServoPulse(uint8_t n, double pulse) {
  double pulselength;
  pulselength = 1000000;
  pulselength /= SERVO_FREQ;
  Serial.print(pulselength); Serial.println(" us per period"); 
  pulselength /= 4096;
  Serial.print(pulselength); Serial.println(" us per bit"); 
  pulse *= 1000000;
  pulse /= pulselength;
  Serial.println(pulse);
  pwm.setPWM(n, 0, pulse);
}

void loop() {
  if(SerialBT.available()){
    char c = SerialBT.read();
    Serial.println(servonum);
    if(c == '1'){
      pwm.setPWM(0, 0, 150);
    }
    if (c == '2'){
      pwm.setPWM(0, 0, 475);
    }
    if (c == '3'){
      pwm.setPWM(0, 0, 600);
    }
    if(c == '4'){
      pwm.setPWM(1, 0, 150);
    }
    if (c == '5'){
      pwm.setPWM(1, 0, 475);
    }
    if (c == '6'){
      pwm.setPWM(1, 0, 600);
      }

    delay(500);
  }
}

(``` added for indents - ABG)

2

You might look here

Your question is really an Arduino question and can be answered on the Arduino forums probably.

3

To receive multicharacter messages, you will need the readuntil command.

Search this board for 'readuntil' for threads discussing it.

4

This should work ( I don't have the pwm so I have commented that part ).
The commands ( N01, F01... ) should be terminated with a '\n' or a '\r'

blue01.ino (2.1 KB)
bt01.aia (2.0 KB)