{
  "format": "evn-blocks",
  "version": 1,
  "needs": "a robot: left wheel motor on port 4 (mounted mirrored), right on port 3, 62.4 mm wheels 170 mm apart, an EVN IMU on I2C port 3 fixed to the chassis, and 40 cm of clear floor ahead. Keep the robot still while the program starts (the IMU settles in 8 to 25 s).",
  "workspace": {
    "blocks": {
      "languageVersion": 0,
      "blocks": [
        {
          "type": "evn_motor_setup",
          "fields": {
            "PORT": "4",
            "DIRECTION": "CCW",
            "UNIT": "DEG_S"
          },
          "x": 20,
          "y": 20
        },
        {
          "type": "evn_drivebase_setup",
          "fields": {
            "LEFT": "4",
            "RIGHT": "3",
            "WHEEL": 62.4,
            "TRACK": 170
          },
          "x": 20,
          "y": 70
        },
        {
          "type": "evn_imu_setup",
          "fields": {
            "PORT": "3"
          },
          "x": 20,
          "y": 120
        },
        {
          "type": "evn_drivebase_gyro",
          "fields": {
            "PORT": "3"
          },
          "x": 20,
          "y": 190,
          "next": {
            "block": {
              "type": "evn_imu_reset_heading",
              "fields": {
                "PORT": "3"
              },
              "next": {
                "block": {
                  "type": "evn_drivebase_straight",
                  "fields": {
                    "THEN": "HOLD",
                    "WAIT": "TRUE"
                  },
                  "inputs": {
                    "DISTANCE": {
                      "shadow": {
                        "type": "math_number",
                        "fields": {
                          "NUM": 300
                        }
                      }
                    }
                  },
                  "next": {
                    "block": {
                      "type": "evn_drivebase_turn",
                      "fields": {
                        "THEN": "HOLD",
                        "WAIT": "TRUE"
                      },
                      "inputs": {
                        "ANGLE": {
                          "shadow": {
                            "type": "math_number",
                            "fields": {
                              "NUM": 45
                            }
                          }
                        }
                      },
                      "next": {
                        "block": {
                          "type": "evn_drivebase_turn",
                          "fields": {
                            "THEN": "HOLD",
                            "WAIT": "TRUE"
                          },
                          "inputs": {
                            "ANGLE": {
                              "shadow": {
                                "type": "math_number",
                                "fields": {
                                  "NUM": -45
                                }
                              }
                            }
                          },
                          "next": {
                            "block": {
                              "type": "evn_drivebase_turn",
                              "fields": {
                                "THEN": "HOLD",
                                "WAIT": "TRUE"
                              },
                              "inputs": {
                                "ANGLE": {
                                  "shadow": {
                                    "type": "math_number",
                                    "fields": {
                                      "NUM": 180
                                    }
                                  }
                                }
                              },
                              "next": {
                                "block": {
                                  "type": "evn_drivebase_straight",
                                  "fields": {
                                    "THEN": "HOLD",
                                    "WAIT": "TRUE"
                                  },
                                  "inputs": {
                                    "DISTANCE": {
                                      "shadow": {
                                        "type": "math_number",
                                        "fields": {
                                          "NUM": 300
                                        }
                                      }
                                    }
                                  },
                                  "next": {
                                    "block": {
                                      "type": "evn_drivebase_turn",
                                      "fields": {
                                        "THEN": "HOLD",
                                        "WAIT": "TRUE"
                                      },
                                      "inputs": {
                                        "ANGLE": {
                                          "shadow": {
                                            "type": "math_number",
                                            "fields": {
                                              "NUM": -45
                                            }
                                          }
                                        }
                                      },
                                      "next": {
                                        "block": {
                                          "type": "evn_drivebase_turn",
                                          "fields": {
                                            "THEN": "HOLD",
                                            "WAIT": "TRUE"
                                          },
                                          "inputs": {
                                            "ANGLE": {
                                              "shadow": {
                                                "type": "math_number",
                                                "fields": {
                                                  "NUM": 45
                                                }
                                              }
                                            }
                                          },
                                          "next": {
                                            "block": {
                                              "type": "evn_drivebase_turn",
                                              "fields": {
                                                "THEN": "HOLD",
                                                "WAIT": "TRUE"
                                              },
                                              "inputs": {
                                                "ANGLE": {
                                                  "shadow": {
                                                    "type": "math_number",
                                                    "fields": {
                                                      "NUM": -180
                                                    }
                                                  }
                                                }
                                              },
                                              "next": {
                                                "block": {
                                                  "type": "text_print",
                                                  "inputs": {
                                                    "TEXT": {
                                                      "block": {
                                                        "type": "text_join",
                                                        "extraState": {
                                                          "itemCount": 2
                                                        },
                                                        "inputs": {
                                                          "ADD0": {
                                                            "shadow": {
                                                              "type": "text",
                                                              "fields": {
                                                                "TEXT": "robot angle (deg): "
                                                              }
                                                            }
                                                          },
                                                          "ADD1": {
                                                            "block": {
                                                              "type": "evn_drivebase_measure",
                                                              "fields": {
                                                                "WHAT": "angle"
                                                              }
                                                            }
                                                          }
                                                        }
                                                      }
                                                    }
                                                  },
                                                  "next": {
                                                    "block": {
                                                      "type": "text_print",
                                                      "inputs": {
                                                        "TEXT": {
                                                          "block": {
                                                            "type": "text_join",
                                                            "extraState": {
                                                              "itemCount": 2
                                                            },
                                                            "inputs": {
                                                              "ADD0": {
                                                                "shadow": {
                                                                  "type": "text",
                                                                  "fields": {
                                                                    "TEXT": "IMU heading (deg): "
                                                                  }
                                                                }
                                                              },
                                                              "ADD1": {
                                                                "block": {
                                                                  "type": "evn_imu_angle",
                                                                  "fields": {
                                                                    "PORT": "3",
                                                                    "WHAT": "heading()"
                                                                  }
                                                                }
                                                              }
                                                            }
                                                          }
                                                        }
                                                      },
                                                      "next": {
                                                        "block": {
                                                          "type": "evn_drivebase_stop",
                                                          "fields": {
                                                            "ACTION": "stop"
                                                          }
                                                        }
                                                      }
                                                    }
                                                  }
                                                }
                                              }
                                            }
                                          }
                                        }
                                      }
                                    }
                                  }
                                }
                              }
                            }
                          }
                        }
                      }
                    }
                  }
                }
              }
            }
          }
        }
      ]
    }
  }
}