====== Ictu() ======

''Ictu()'' counts input rising edges and returns true when the preset value is reached.

{{:en-us_commands:reference:ictu.svg?900|Ictu command operation flow}}

''bool Ictu(uint8_t counter_id, bool CU, bool RESET, int32_t PV)''

===== Commands =====

^ Command ^ Arguments ^ Return Value ^ Operation ^
| ''Ictu(counter_id, CU, RESET, PV)'' | ''uint8_t counter_id'' — Counter identifier. Use the same number for the same counting task\\ ''bool CU'' — Count input. Increments by 1 when it changes from LOW to HIGH\\ ''bool RESET'' — When true, reset the current count to 0\\ ''int32_t PV'' — Target count. Returns true when the current count reaches or exceeds this value | ''bool'' | Count rising input edges and return true when the preset is reached. |

**Beginner-friendly explanation**

''Ictu()'' does not measure how long a sensor stays on. It counts how many times the sensor changes from ''LOW'' to ''HIGH''. For example, when one item passes the sensor, the input changes ''LOW → HIGH → LOW'' and the counter increases by 1. A sensor that remains ''HIGH'' is counted only once.

Read the call ''Ictu(counter_id, CU, RESET, PV)'' as follows.

  * ''counter_id'': Identifies one counter among several counters. Always use the same number for the same counting task.
  * ''CU'': The count input. The current count increases by 1 when this input changes from ''LOW → HIGH''.
  * ''RESET'': When ''true'', clears the current count to 0. While RESET is active, CU is not counted even if it turns on.
  * ''PV'': The target count. The return value becomes ''true'' when the current count reaches or exceeds this value.

Call it continuously from ''loop()'' so it can detect input changes. The example below counts five items with input 0 and turns on the board's status LED when the target is reached. Pressing the reset button on input 1 starts the count again from zero.


===== Example =====

<code cpp>
const uint8_t COUNTER_ID = 0;
const uint8_t ITEM_SENSOR_PIN = 0;
const uint8_t RESET_BUTTON_PIN = 1;
const uint8_t FULL_LAMP_PIN = LED_BUILTIN;
const int32_t BOX_CAPACITY = 5;

void setup() {
  Serial.begin(115200);
}

void loop() {
  const bool itemSensor = digitalRead(ITEM_SENSOR_PIN) == HIGH;
  const bool resetButton = digitalRead(RESET_BUTTON_PIN) == HIGH;
  const bool boxFull = Ictu(COUNTER_ID, itemSensor, resetButton, BOX_CAPACITY);  // Count rising input edges and return true when the preset is reached.
  digitalWrite(FULL_LAMP_PIN, boxFull ? HIGH : LOW);

  static bool previousBoxFull = false;
  if (boxFull && !previousBoxFull) {
    Serial.println(F("5 items counted: box is full"));
  }
  previousBoxFull = boxFull;
}
</code>

===== Precautions =====

  * ''CU'' counts only ''LOW → HIGH'' transitions. If the signal remains ''HIGH'', the count increases only once.
  * When ''RESET'' is ''true'', the current count is cleared to 0 and ''CU'' is not counted during that call.
  * Set ''PV'' to a target count of 1 or greater. If ''PV'' is 0 or less, the initial count of 0 is already considered to have reached the target.
  * Input changes can be missed when sensor pulses are faster than ''loop()''. Use the product's high-speed counter for fast pulses.
  * Use a different ''counter_id'' for each counting task. Do not share one number among CTU, CTD, and CTUD.
  * Use ''IgetCount()'' with the same ''counter_id'' only when you need the current count.

===== Built-in Commands in the Same Category =====

  * [[:en-us_commands:reference:ictd|Ictd() View detailed description]]
  * [[:en-us_commands:reference:ictud|Ictud() View detailed description]]
  * [[:en-us_commands:reference:igetcount|IgetCount() View detailed description]]
  * [[:en-us_commands:reference:isetcount|IsetCount() View detailed description]]
  * [[:en-us_commands:reference:ictuddownstate|IctudDownState() View detailed description]]

[[:en-us_commands:builtin|← Built-in Command List]]