microReticulumTbeam/exercises/16_PSRAM/README.md

Exercise 16: PSRAM

This exercise demonstrates usage of PSRAM (Pseudo SRAM) on an ESP32-S3 board, alongside regular RAM metrics.

Behavior:

• Reports heap and PSRAM statistics every second over serial.
• Shows live heap and PSRAM status on the OLED display (both on same line).
• Allows you to write/append/read/clear data in a PSRAM-backed buffer (up to ~2MB).
• Designed as an extension of Exercise 15_RAM to explore larger volatile storage.

Note: the exercise now targets a PSRAM-enabled ESP32-S3 board definition (freenove_esp32_s3_wroom). This board profile has 8MB flash + 8MB PSRAM, matching the T-Beam Supreme specifications. If your hardware differs, adjust accordingly.

Sources:

• LilyGo T-Beam SUPREME datasheet/wiki: https://wiki.lilygo.cc/get_started/en/LoRa_GPS/T-Beam-SUPREME/T-Beam-SUPREME.html
• PlatformIO board definition: https://docs.platformio.org/page/boards/espressif32/freenove_esp32_s3_wroom.html
• Local PlatformIO board metadata: ~/.platformio/platforms/espressif32/boards/freenove_esp32_s3_wroom.json

Build and upload:

cd /usr/local/src/microreticulum/microReticulumTbeam/exercises/16_PSRAM
pio run -e amy -t upload
pio device monitor -b 115200

Commands:

• help - show command menu
• stat - show PSRAM buffer state
• read - read PSRAM buffer contents
• clear - clear PSRAM buffer
• write <text> - write text to PSRAM buffer
• append <text> - append text to PSRAM buffer