# SPI Slave Halfduplex: Segment Mode Examples (See the README.md file in the 'examples' directory for more information about IDF examples.) These two projects illustrate the SPI Slave Halfduplex Segment Mode. * ``seg_slave`` shows one of the ways to use the SPI Slave Halfduplex driver. There are 2 tasks repeating to receive/send transactions from/to SPI Master respectively. * ``seg_master`` shows how to use the ESP Serial Slave Link APIs to communicate with SPI Slave Halfduplex driver. It receives/sends transactions from/to slave a few times. ## How to use example ### Hardware Required These two projects are supposed to be flashed onto two seperate boards and jumped together via correctly connected SPI pins defined in both of the ``app_main.c`` files. For the ``seg_master`` project, it could be flashed onto all the ESP Chips. Whereas the ``seg_slave`` currently could be flashed onto ESP32-S2. Once they are connected and flashed, they will use the SPI Master and SPI Slave Halfduplex drivers to communicate with each other. Following is the connection between 2 ESP32S2 boards: | Signal | Master | Slave | |-----------|--------|--------| | MOSI | GPIO11 | GPIO11 | | MISO | GPIO13 | GPIO13 | | SCLK | GPIO12 | GPIO12 | | CS | GPIO10 | GPIO10 | (Feel free to change the GPIO settings by editing the macro definations at the top of ``app_main.c`` files.) ### Build and Flash Run `idf.py -p PORT flash monitor` to build, flash and monitor the project. (To exit the serial monitor, type ``Ctrl-]``.) See the [Getting Started Guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html) for full steps to build, flash and monitor projects. ## Example Output ``seg_master`` ``` ---------SLAVE INFO--------- Slave MAX Send Buffer Size: 5000 Slave MAX Receive Buffer Size: 120 I (328) SEG_MASTER: RECEIVING...... Transaction No.0 from slave, length: 4640 I (338) SEG_MASTER: SENDING...... I (348) SEG_MASTER: RECEIVING...... Transaction No.1 from slave, length: 3299 I (348) SEG_MASTER: SENDING...... I (358) SEG_MASTER: RECEIVING...... Transaction No.2 from slave, length: 4836 I (368) SEG_MASTER: SENDING...... I (368) SEG_MASTER: RECEIVING...... Transaction No.3 from slave, length: 3333 I (378) SEG_MASTER: SENDING...... I (378) SEG_MASTER: RECEIVING...... Transaction No.4 from slave, length: 4965 I (388) SEG_MASTER: SENDING...... I (388) SEG_MASTER: RECEIVING...... Transaction No.5 from slave, length: 3042 I (398) SEG_MASTER: SENDING...... I (408) SEG_MASTER: RECEIVING...... Transaction No.6 from slave, length: 4892 I (408) SEG_MASTER: SENDING...... I (418) SEG_MASTER: RECEIVING...... Transaction No.7 from slave, length: 3585 I (428) SEG_MASTER: SENDING...... I (428) SEG_MASTER: RECEIVING...... Transaction No.8 from slave, length: 3348 I (438) SEG_MASTER: SENDING...... I (438) SEG_MASTER: RECEIVING...... Transaction No.9 from slave, length: 4985 I (448) SEG_MASTER: SENDING...... I (448) SEG_MASTER: RECEIVING...... Transaction No.10 from slave, length: 3710 ... ``` ``seg_slave`` ``` 77 bytes are received: this is master's transaction 0 109 bytes are received: this is master's transaction 1 83 bytes are received: this is master's transaction 2 97 bytes are received: this is master's transaction 3 47 bytes are received: this is master's transaction 4 89 bytes are received: this is master's transaction 5 80 bytes are received: this is master's transaction 6 96 bytes are received: this is master's transaction 7 83 bytes are received: this is master's transaction 8 110 bytes are received: this is master's transaction 9 113 bytes are received: this is master's transaction 10 ... ``` ## Troubleshooting For any technical queries, please open an [issue](https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you.