# Gate Enables easy opening and closing a message stream in runtime. This example requires the DepthAI v3 API, see [installation instructions](https://docs.luxonis.com/software-v3/depthai.md). ## Pipeline ### examples/gate.pipeline.json ```json { "pipeline": { "bridges": [], "connections": [ { "node1Id": 4, "node1Output": "out", "node1OutputGroup": "", "node2Id": 1, "node2Input": "inputControl", "node2InputGroup": "" }, { "node1Id": 1, "node1Output": "output", "node1OutputGroup": "", "node2Id": 5, "node2Input": "in", "node2InputGroup": "" }, { "node1Id": 0, "node1Output": "0", "node1OutputGroup": "dynamicOutputs", "node2Id": 1, "node2Input": "input", "node2InputGroup": "" } ], "globalProperties": { "calibData": null, "cameraSocketTuningBlobSize": [], "cameraSocketTuningBlobUri": [], "cameraTuningBlobSize": null, "cameraTuningBlobUri": "", "eepromId": 0, "leonCssFrequencyHz": 700000000.0, "leonMssFrequencyHz": 700000000.0, "pipelineName": null, "pipelineVersion": null, "sippBufferSize": 18432, "sippDmaBufferSize": 16384, "xlinkChunkSize": -1 }, "nodes": [ [ 5, { "alias": "", "deviceId": "1936701492", "deviceNode": true, "id": 5, "ioInfo": [ [ [ "", "pipelineEventOutput" ], { "blocking": false, "group": "", "id": 17, "name": "pipelineEventOutput", "queueSize": 8, "type": 0, "waitForMessage": false } ], [ [ "", "in" ], { "blocking": true, "group": "", "id": 16, "name": "in", "queueSize": 3, "type": 3, "waitForMessage": false } ] ], "logLevel": 1, "name": "XLinkOut", "parentId": -1, "properties": [185, 5, 136, 0, 0, 128, 191, 189, 12, 95, 95, 120, 95, 49, 95, 111, 117, 116, 112, 117, 116, 0, 255, 255] } ], [ 4, { "alias": "", "deviceId": "1936701492", "deviceNode": true, "id": 4, "ioInfo": [ [ [ "", "out" ], { "blocking": false, "group": "", "id": 15, "name": "out", "queueSize": 8, "type": 0, "waitForMessage": false } ], [ [ "", "pipelineEventOutput" ], { "blocking": false, "group": "", "id": 14, "name": "pipelineEventOutput", "queueSize": 8, "type": 0, "waitForMessage": false } ] ], "logLevel": 1, "name": "XLinkIn", "parentId": -1, "properties": [185, 3, 189, 19, 95, 95, 120, 95, 49, 95, 95, 105, 110, 112, 117, 116, 67, 111, 110, 116, 114, 111, 108, 130, 0, 6, 26, 1, 8] } ], [ 1, { "alias": "", "deviceId": "1936701492", "deviceNode": true, "id": 1, "ioInfo": [ [ [ "", "output" ], { "blocking": false, "group": "", "id": 8, "name": "output", "queueSize": 8, "type": 0, "waitForMessage": false } ], [ [ "", "pipelineEventOutput" ], { "blocking": false, "group": "", "id": 7, "name": "pipelineEventOutput", "queueSize": 8, "type": 0, "waitForMessage": false } ], [ [ "", "inputControl" ], { "blocking": false, "group": "", "id": 6, "name": "inputControl", "queueSize": 4, "type": 3, "waitForMessage": false } ], [ [ "", "input" ], { "blocking": false, "group": "", "id": 5, "name": "input", "queueSize": 1, "type": 3, "waitForMessage": false } ] ], "logLevel": 1, "name": "Gate", "parentId": -1, "properties": [185, 1, 185, 3, 1, 255, 255] } ], [ 0, { "alias": "", "deviceId": "1936701492", "deviceNode": true, "id": 0, "ioInfo": [ [ [ "dynamicOutputs", "0" ], { "blocking": false, "group": "dynamicOutputs", "id": 4, "name": "0", "queueSize": 8, "type": 0, "waitForMessage": false } ], [ [ "", "pipelineEventOutput" ], { "blocking": false, "group": "", "id": 2, "name": "pipelineEventOutput", "queueSize": 8, "type": 0, "waitForMessage": false } ], [ [ "", "raw" ], { "blocking": false, "group": "", "id": 3, "name": "raw", "queueSize": 8, "type": 0, "waitForMessage": false } ], [ [ "", "mockIsp" ], { "blocking": true, "group": "", "id": 1, "name": "mockIsp", "queueSize": 8, "type": 3, "waitForMessage": false } ], [ [ "", "inputControl" ], { "blocking": true, "group": "", "id": 0, "name": "inputControl", "queueSize": 3, "type": 3, "waitForMessage": false } ] ], "logLevel": 1, "name": "Camera", "parentId": -1, "properties": [185, 22, 185, 33, 0, 3, 0, 136, 0, 0, 0, 0, 128, 203, 128, 175, 185, 3, 130, 210, 60, 167, 206, 130, 27, 150, 152, 107, 130, 147, 182, 86, 184, 185, 5, 129, 144, 132, 129, 12, 171, 129, 31, 57, 129, 112, 19, 130, 149, 218, 232, 115, 185, 5, 129, 88, 123, 129, 60, 187, 129, 70, 49, 129, 114, 149, 130, 159, 68, 240, 46, 54, 128, 240, 128, 168, 0, 0, 128, 152, 128, 177, 128, 221, 128, 185, 185, 3, 44, 128, 139, 132, 139, 185, 3, 134, 92, 234, 227, 32, 134, 1, 55, 201, 148, 130, 10, 242, 221, 79, 130, 36, 65, 196, 239, 15, 82, 230, 209, 128, 228, 0, 0, 129, 156, 212, 128, 239, 24, 0, 186, 0, 0, 255, 189, 0, 255, 255, 255, 255, 255, 136, 0, 0, 128, 191, 136, 0, 0, 128, 191, 0, 3, 134, 0, 0, 160, 0, 3, 134, 0, 0, 160, 0, 4, 4, 4, 190, 190, 186, 1, 185, 6, 185, 1, 184, 0, 186, 2, 129, 128, 2, 129, 144, 1, 185, 1, 184, 0, 136, 0, 0, 240, 65, 190, 0, 190, 0] } ] ] } } ``` ## Source code #### Python ```python import time import cv2 import depthai as dai device = dai.Device() withGate = True with dai.Pipeline(device) as pipeline: camera = pipeline.create(dai.node.Camera).build() cameraOut = camera.requestOutput((640, 400), fps=30) gate = pipeline.create(dai.node.Gate) cameraOut.link(gate.input) cameraQueue = gate.output.createOutputQueue() gateControlQueue = gate.inputControl.createInputQueue() gateControl = dai.GateControl() pipeline.start() ellapsed = 0 startTime = time.monotonic() gateOpen = True while pipeline.isRunning(): frame = cameraQueue.tryGet() if frame is not None: cv2.imshow("camera", frame.getCvFrame()) currentTime = time.monotonic() elapsed = currentTime - startTime if elapsed > 5.0: # 5 seconds # Toggle the value gateOpen = not gateOpen # Create and send the control message if (gateOpen): gateControlQueue.send(dai.GateControl.openGate()) else: gateControlQueue.send(dai.GateControl.closeGate()) print(f"Gate toggled to: {gateOpen}") # Reset the timer startTime = currentTime key = cv2.waitKey(1) if key == ord('q'): pipeline.stop() break ``` #### C++ ```cpp #include #include #include #include // DepthAI and OpenCV headers #include #include "depthai/depthai.hpp" #include "depthai/pipeline/node/Gate.hpp" std::atomic quitEvent(false); void signalHandler(int) { quitEvent = true; } int main() { signal(SIGTERM, signalHandler); signal(SIGINT, signalHandler); dai::Pipeline pipeline; auto camera = pipeline.create()->build(); auto cameraOut = camera->requestOutput(std::make_pair(640, 400), std::nullopt, dai::ImgResizeMode::CROP, 30); auto gate = pipeline.create(); cameraOut->link(gate->input); auto cameraQueue = gate->output.createOutputQueue(); auto gateControlQueue = gate->inputControl.createInputQueue(); pipeline.start(); auto startTime = std::chrono::steady_clock::now(); bool openGate = true; while(pipeline.isRunning() && !quitEvent) { auto frame = cameraQueue->tryGet(); if(frame != nullptr) { cv::imshow("camera", frame->getCvFrame()); } auto currentTime = std::chrono::steady_clock::now(); std::chrono::duration elapsed = currentTime - startTime; if(elapsed.count() > 5.0) { openGate = !openGate; if(openGate) { gateControlQueue->send(dai::GateControl::openGate()); } else { gateControlQueue->send(dai::GateControl::closeGate()); } std::cout << "Gate toggled to: " << (openGate ? "True" : "False") << std::endl; startTime = currentTime; } int key = cv::waitKey(1); if(key == 'q') { break; } } pipeline.stop(); pipeline.wait(); return 0; } ``` ### Need assistance? Head over to [Discussion Forum](https://discuss.luxonis.com/) for technical support or any other questions you might have.