Stop Sign Detection

This part utilize a Google Coral accelerator and a pre-trained object detection model by Coral project to perform stop sign detection. If the donkey car see a stop sign, it will override the pilot/throttle to 0. In addition, a bounding box will be annotated to the cam/image_array.


To use this part, you must have:

How to use

Put the following lines in


Install Edge TPU dependencies

Follow this instruction to install and setup Google Coral on Pi 4

In addition, install the dependency on your dev pc or pi4 like this

pip3 install

Detecting other objects

Since the pre-trained model are trained on coco, there are 80 objects that the model is able to detect. You can simply change the STOP_SIGN_CLASS_ID in to try.


Since SSD is not good at detecting small objects, the accuracy of detecting the stop sign from far away may not be good. There are some ways that we can make enhancement but this is out of the scope of this part.