NOTE!

OAK IoT series and this repository is community supported only, and is provided as-is. We most likely won't update it and we don't provide support for it (Discord, forums, email...).

Demo

See below for this running on the BW1092:

And see https://github.com/luxonis/depthai-experiments/tree/master/gen2-spi for pulling off JPEG and/or depth (including cropping on DepthAI) instead of the MobileNetv2-SSD or tinyYOLOv3 metadata shown below.

Building

The first time you build, the repository submodules need be initialized:

git submodule update --init --recursive

# Tip: You can ask Git to do that automatically:
git config submodule.recurse true

Later submodules also need to be updated. To build an example, you will need to use ESP-IDF's idf.py. Examples here were only tested with ESP-IDF version 4.1 and we encourage you to use the same version as well.

SPI Protocol

SPI messaging is currently arranged in 2 layers. The first is the spi protocol. The spi protocol is the lowest level. It defines a standard packet for all SPI communication. It is a 256 byte packet arranged in the following manner:

typedef struct {
    uint8_t start;
    uint8_t data[SPI_PROTOCOL_PAYLOAD_SIZE];
    uint8_t crc[2];
    uint8_t end;
} SpiProtocolPacket;

start and end are constant bytes to mark the beginning and end of packets.

static const uint8_t START_BYTE_MAGIC = 0b10101010;
static const uint8_t END_BYTE_MAGIC = 0b00000000;

SPI Messaging

On top of this we have a layer called SPI messaging. This code defines the following:

• A list of a supported commands,
• A way to encapsulate commands going to the MyriadX over SPI.
• A way to receive and parse command responses.
• We’ll go into greater depth as to how exactly to use this in the SPI Messaging Example.

The SPI Messaging Examples

We have a few SPI messaging examples in the depthai-experiments repository. Please see the following: https://github.com/luxonis/depthai-experiments/tree/master/gen2-spi