Blocks

It is assumed that you already know how to use Blocks. If not, be sure to check out the Blocks Programming Guide document before proceeding.

  1. First click the “Create New Op Mode” button in the Blocks main management interface.

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  1. Select “ConceptTensorFlowObjectDetectionCustomModel” in the sample drop down and choose whatever name you find appropriate. Then click OK.

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Note

Be careful of a common pitfall – as of SDK 7.0, normal TensorFlow blocks cannot load custom tensorflow models. There are TWO kinds of TensorFlow blocks, one type for regular models and one type for custom models, and ALL of the blocks in each category MUST be used together (so old programs that load regular models would need ALL of the TensorFlow blocks replaced, not just the ones that load the model). If you choose to not create a new Op Mode for loading the Custom Models, and you do not replace ALL of the “normal” TensorFlow blocks, be aware that we warned you here.

  1. You can either use a webcam or the built in camera for your video input. If you are using the control hub you, do not have a built in camera. If you are using the phone’s built in camera do not change the disabled block. If you are using a webcam, disable the block of code below the comment “The following block(first image below) uses the device’s back camera.” To disable the block right click the block and select “Disable Block.” Then enable the following block (second image below). Do so by right clicking the block and clicking “Enable Block”.

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  1. If you are using a webcam change the cameraName parameter in the block that you just enabled to the name of your webcam. Currently it is called “Webcam 1.”

  2. Then scroll down to the following block.

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You will now have to modify the name of the model that the opmode uses. To do this change the tfliteModelFilename string from “WiffleBalls.tflite” to the name of the file that you will upload. If you don’t use the model uploader, you need to specify the fully qualified path to where the tflite models live. An example of the fully qualified path to where the tflite models live can be seen in the example below:

/sdcard/FIRST/tflitemodels/myCustomFreightFrenzyModel.tflite

Tip

On some older models of phones, the upload path may be different. On some phones, like the Motorola G2 phone, the model path should instead be set to /storage/emulated/0/FIRST/tflitemodels/myCustomFreightFrenzyModel.tflite

  1. Next you will have to update the labels. This should match the order of the labels in the dataset(s) that your model is based on. To do so click on the gear icon and add the needed number of items. Then add the items in your model to the labels list (seen below). This should be in alphabetical order and match the labels in the dataset(s) that your model is made from.

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  1. The next step is to upload the TFOD model that you created using FTC-ML. To do this go to the ribbon on the top of your windows and select “Manage”.

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  1. If you’re using SDK 7.0 or older, select the “Upload TensorFlow Lite Model File” button and select the model (.tflite). Then click upload.

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If you’re using SDK 7.1 and newer, in the same location you’ll find a TensorFlow Lite Model File Manager link. Click on that link to take you to the model file manager, and upload your model. Here you can also view other models already uploaded, rename, and delete models.

  1. And you are all set to test. After building the opmode as you would any other opmode and select initialize and play. Have fun testing.