What is MetalHead and the short story behind the name

System Block Diagram

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Firmware

Interface Board

We are using ArduinoJson to serialize and deserialize json objects between the Interface Board and HMI. All JSON objects will have ObjectType to identify the type of message being transferred or received. This will make it easy to deserialize a JSON object into one of our own objects.

Recipe

The following JSON object is used inside of PresetRecipes

{
  "ObjectType": "Recipe",
  "Lines": [[0,0,0,0,0], [], [], [], [], ...],
  "rebarSize": 0,
  "name": "12x12 Square",
  "desc": "A basic 1 x 1' square stirrup",
  "note": "Add some compensation for #5 or #6",
  "date": 1739089653
}

PresetRecipes

The following JSON object is transferred to the HMI from the Interface Board via UART. This object holds all preset recipes saved in the EEPROM.

We could also implement this into the HMI application

{
  "ObjectType": "PresetRecipes",
  "NumofRecipes": 16,
  "Recipes": [Recipe{}, Recipe{}, ...]
}

PresetRecipe

The following JSON object is transferred to the Interface Board from the HMI UART. This object holds a recipe that the operator wishes to save.

{
  "ObjectType": "PresetRecipe",
  "Recipe": {}
}

ManualRecipe

The following JSON object is transferred to the Interface Board from the HMI via UART. This object instructs the interface to make the following recipe.

{
  "ObjectType": "ManualRecipe",
  "Recipe": {}
}

StopEvent

The following JSON object is transferred to the HMI from the Interface Board via UART. This object instructs the HMI to display a message. There are currently two types of events.

{
  "ObjectType": "StopEvent",
  "Event": "EStop"
}

{
  "ObjectType": "StopEvent",
  "Event": "Fuse"
}

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Keypad

Similarly to the Interface Board, we are using ArduinoJson to serialize and deserialize json objects between the Keypad and HMI

KeypadEvent - Structure

KeypadEvent is sent to the Interface Board via UART when the operator hits a key. Multiple KeypadEvent[s] will be sent to the Interface Board if the operator depresses a key for longer than a typical keystroke. Below are a few examples of what a KeypadEvent structure sent via UART to the Interface Board would look like. Since the Keypad communicates to the HMI uni-directionally on its own separate UART channel, we will not include ObjectType in the JSON object.

{
  "Key": "DISPLAY"
}

{
  "Key": "COMP"
}

{
  "Key": "UPARROW"
}

Key Mapping

Because we are going to be using two 16 bit I2C GPIO expanders, we are going to map each key to a specific bit on a I2C address.

I2C Read Address	Bit	Key
0x41	0	Display
0x41	1	Comp
0x41	3	Infeed
0x41	4	Head Pos
0x41	5	Form Tool In
0x41	6	Shear
0x41	7	Pause
0x41	8	Run
0x41	9	Up
0x41	10	Enter
0x41	11	1
0x41	12	2
0x41	13	3
0x41	14	Plus
0x41	15	Left
0x43	0	Menu
0x43	1	Right
0x43	3	4
0x43	4	5
0x43	5	6
0x43	6	Minus
0x43	7	Memory
0x43	8	Down
0x43	9	Decimal
0x43	10	7
0x43	11	8
0x43	12	9
0x43	13	0

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Software

HMI

KeypadEvent

When the HMI receives a KeypadEvent from the keypad, the object is forwarded to the Interface Board for processing. The following is an example of how a KeypadEvent looks like when the HMI sends it to the Interface Board.

{
  "ObjectType": "KeypadEvent",
  "Event": "SHEAR"
}

{
  "ObjectType": "KeypadEvent",
  "Event": "PAUSE"
}

The following keys are forwarded to the Interface Board from the HMI:

• FORM TOOL IN
• SHEAR
• PAUSE
• RUN

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Hardware

Interface Board

A brief explanation of what this does and how it achieves it. Mention the added SBC for the GUI.

Keypad

A brief explanation of what this does and how it achieves it.

SBC