Accessory Shield for Bluno - OLED not working with motor drivers

#include "blunoAccessory.h"
#include "U8glib.h"
#include <DHT.h>


#define DHTPIN            2         // Pin which is connected to the DHT sensor.
#define DHTTYPE           DHT11     // DHT 22 (AM2302)

DHT dht(DHTPIN, DHTTYPE);
U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE);
blunoAccessory myAccessory;

//Sensor
char Humm_buf[6];
char Temp_buf[6];
float temperature;
float humidity;

//Motor
int E1 = 5;     //M1 Speed Control
int E2 = 6;     //M2 Speed Control
int M1 = 4;     //M1 Direction Control
int M2 = 7;     //M1 Direction Control

void setup() {
  u8g.setColorIndex(2);             //displayMode : u8g_MODE_BW
  myAccessory.begin();
  dht.begin(); 
}

void loop() {
  static unsigned long DHT11Timer=millis();       //every 2s update the temperature and humidity from DHT11 sensor
  if (millis() - DHT11Timer >= 1000) 
  {
      DHT11Timer=millis();
      temperature=dht.readTemperature();
      humidity=dht.readHumidity();
  }

  u8g.firstPage();
  do
  {
    //motor(); //<--- problem is here
    draw();
  }
  while(u8g.nextPage());
  delay(500);
}

void draw (void)
{
  dtostrf(humidity,5,0,Humm_buf);
  dtostrf(temperature,5,0,Temp_buf);
  
  u8g.setFont(u8g_font_unifont);
  u8g.drawStr(0,22,"Humidity ");
  u8g.drawStr(70,22,Humm_buf);
  u8g.drawStr(113,22,"%");
  
  u8g.drawStr(0,44,"Temperature ");
  u8g.drawStr(70,44,Temp_buf);
  u8g.drawCircle(113,37,2);
  u8g.drawStr(117,44,"C");
}

void motor(void)
{
  digitalWrite(M1, LOW); //LOW or HIGH 
  analogWrite (E1, 255); //PWM Speed Control
  digitalWrite(M2, HIGH); //LOW or HIGH
  analogWrite (E2, 100); //PWM Speed Control
}