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third_party/tinyusb/examples/device/usbtmc/README.md

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+# USBTMC
+
+A USB Test & Measurement Class (USBTMC) instrument with USB488/SCPI support, behaving like a simple programmable instrument.
+
+## What it does
+
+- Implements a USBTMC interface with USB488 capabilities and advertises SCPI support.
+- Responds to `*IDN?` with an identification string (`TinyUSB,ModelNumber,SerialNumber,FirmwareVer123456`).
+- Buffers other written messages and echoes them back as the query response, after a configurable delay.
+- A `delay <ms>` command adjusts that simulated response delay (0–10000 ms).
+- Maintains an IEEE-488.2 status byte (MAV/SRQ), and handles trigger, clear, and bulk abort requests.
+- Supports the USBTMC indicator-pulse request, which briefly pulses the board LED.
+- Uses an interrupt endpoint in addition to the bulk IN/OUT endpoints.
+
+## USB Descriptors
+
+| Interface | Class driver |
+|-----------|--------------|
+| 0 | USBTMC |
+
+## Configuration
+
+Notable `tusb_config.h` settings:
+
+```c
+#define CFG_TUD_USBTMC                1
+#define CFG_TUD_USBTMC_ENABLE_INT_EP  1
+#define CFG_TUD_USBTMC_ENABLE_488     1
+```
+
+## Building
+
+CMake:
+
+```bash
+mkdir build && cd build
+cmake -DBOARD=raspberry_pi_pico ..
+cmake --build .
+```
+
+Make:
+
+```bash
+make BOARD=raspberry_pi_pico all
+```
+
+## Try it
+
+The device appears as a USBTMC test-and-measurement instrument. Talk to it with a VISA/SCPI tool (for example PyVISA). The included `visaQuery.py` opens the instrument and sends `*IDN?`:
+
+```bash
+python visaQuery.py
+```