Added timeout for stepper drivers

firmware/base/src/main.c

@@ -32,6 +32,7 @@ static double wheel_ratio_r = 1;
 static uint prev_time;
 static int prev_position_l = 0;
 static int prev_position_r = 0;
+static uint last_speed_change = 100;
 
 
 static unsigned char stepper_instr[2+sizeof(double)*2] = {};
@@ -212,6 +213,7 @@ void stepper_fifo(char c, uint8_t itf) {
         double vr = btod(stepper_instr + 10);
 
         set_speeds(vl, vr);
+        last_speed_change = SPEED_SET_TIMEOUT;
 
         // tud_cdc_n_write(itf, (uint8_t const *) stepper_instr, 18);
         // tud_cdc_n_write_flush(itf);
@@ -263,6 +265,10 @@ int main()
     
     
     while (true) {
+        if(last_speed_change--) {
+            set_speeds(0,  0);
+            last_speed_change = SPEED_SET_TIMEOUT;
+        }
         tud_task();
         sleep_ms(1);
     }