waveshare USB to UART/I2C/SPI/JTAG Converter, Supports Multiple Interfaces, Compatible with 3.3V and 5V, Multiple Systems Support, Support Linux (Only for Raspberry Pi)
Quick take
This waveshare USB to UART/I2C/SPI/JTAG Converter is a multi-interface debug adapter built for common bring-up and recovery tasks, including 2-channel UART logging, 1-channel I2C access, 1-channel SPI control, and a JTAG path for debugging. It includes 3.3V/5V level conversion, and its hardware flow control and protection circuits are designed for smoother, safer connections. The main buying caveat is that JTAG usefulness depends on your specific chip and toolchain, so treat it as something you may need to validate end to end.
Pros and cons
Pros
- Flexible interface modes: dual UART (up to 9Mbps), or UART plus I2C plus SPI, or UART plus JTAG.
- 3.3V/5V level conversion helps it connect to devices using common logic voltages.
- UART hardware flow control (CTS/RTS) supports more reliable serial links.
- Aluminium alloy enclosure with multiple protection elements for stable, everyday lab use.
Cons
- JTAG is explicitly positioned for debugging, but you may need to evaluate compatibility with your chip and software.
- Interface-to-connector/port mapping can be confusing if the device is totally dead, so plan how you will confirm channels.
What buyers think
Buyer feedback trends toward “solid and easy to use” for serial debugging and hardware recovery workflows. Multiple reviewers highlight that it works well with terminal tools on Linux distributions (for example, using serial programs like minicom or picocom) and that the voltage selection feature is straightforward. Reviewers also mention that the unit feels more substantial than basic bare PCB or “gumstick” style adapters, and that status indications are helpful when diagnosing whether communications are happening. Where negatives come up, the concerns are mostly practical, such as not immediately knowing which channel maps to which port on the host when the target is unresponsive, and a general caution about trusting unknown driver/tool setups for more complex JTAG workflows.
What this adapter actually does (and the key modes)
This is a USB debug converter that can expose multiple protocols, but the device is intended to be used in different interface combinations. In real workflows, that matters because you may be planning around which pins and signals you need at the same time.
UART (including dual-channel)
- Supports USB to 2-channel UART, and also supports mode combinations that include UART alongside other buses.
- Claims up to 9Mbps baud rate for the high-speed UART use case.
- Includes CTS/RTS hardware automatic flow control for better reliability than basic TX/RX-only links.
I2C for EEPROM, sensors, and OLED-style devices
- Supports 1-channel I2C, useful for reading and writing EEPROM data and for programming or testing I2C peripherals.
SPI with dual chip select capability
- Supports 1-channel SPI.
- Provides 2 chip select signals, allowing you to control 2 SPI slave devices at different times.
JTAG for debugging and testing
- Supports 1-channel JTAG.
- Works with OpenOCD for debugging and testing, with the expectation that you may need to validate chip and software compatibility yourself.
3.3V and 5V level switching, plus protection features
One of the biggest practical concerns when using serial adapters is accidentally connecting a 5V device to 3.3V logic (or vice versa). This adapter includes a 3.3V/5V level conversion circuit for switching the interface operating level, aiming for better compatibility across typical embedded targets.
It also includes protection elements intended to improve safe operation, including a resettable fuse and ESD protection (described as guarding against over-current and over-voltage conditions). For everyday bench work, that can reduce the “how fragile is this link” anxiety when you are swapping targets during debugging.
Setup and day-to-day usability
Reviewers generally describe the device as easy to put into use and useful beyond one narrow purpose. For Linux users, feedback points to compatibility with serial terminal workflows (for example, using minicom and picocom). Status lights are also called out as genuinely helpful for diagnosis, with reviewers describing them as steady and useful for understanding whether communication is active.
If you plan to use multiple UART ports, or you are troubleshooting a device that is not responding, be aware that identifying which host COM port corresponds to which channel may take some effort. A practical approach is to verify mapping by using a known-good test method (for example, checking that TX/RX echo on the expected channel), rather than assuming the first port is always the one you want.
Pros and cons recap
Who it’s best for
- Embedded developers and lab users who need one adapter to cover UART plus at least one of I2C, SPI, or JTAG.
- People working with mixed-voltage targets who want 3.3V/5V level conversion built in.
- Anyone doing firmware bring-up, EEPROM access, SPI peripheral testing, or hardware recovery that involves debugging interfaces.
Who should consider other options
- If you only need basic UART for serial console logging, a simpler UART-only adapter may be less hassle and potentially more cost-effective.
- If your main goal is JTAG with a very specific chip and toolchain, plan to verify compatibility, since complex debugging setups can be sensitive to target and configuration details.
Verdict: is the waveshare adapter worth it?
The waveshare USB to UART/I2C/SPI/JTAG Converter is a strong fit when you want a single, more capable tool for multiple embedded communication buses. Its combination of multi-mode support, 3.3V/5V level conversion, and UART hardware flow control addresses several common pain points in debugging and hardware recovery. The tradeoff is that advanced use cases, especially JTAG, may require validation for your specific chip and software environment. If you are prepared to test and map your channels during setup, this adapter can be a practical “one box for many interfaces” option for a desktop lab.
Price and availability
Check the current price and shipping availability on Amazon, since pricing can vary by seller and timing. Use the button below to see the latest listing details.
FAQ
Is this USB to UART only, or does it support I2C, SPI, and JTAG too?
It supports several interface modes, including dual-channel UART, UART plus I2C plus SPI, and UART plus JTAG. You use the relevant combination depending on what signals you need.
Does it support 3.3V and 5V targets?
Yes. It includes onboard 3.3V and 5V level conversion so you can switch the logic level for compatibility with common embedded device voltages.
What is the maximum UART speed?
The adapter is specified to support up to 9Mbps baud rate for the high-speed UART interface mode.
Will it work on Linux?
It is positioned for Linux usage. Buyer reports also indicate it can work on non-Raspberry Pi Linux systems when using common serial tools.
How reliable is the JTAG support?
It is designed for debugging and testing with OpenOCD, but JTAG depends on the target chip and configuration. Plan to evaluate and validate JTAG functionality for your specific setup.
What should I do if I am not sure which channel is which COM port?
If your device is not responding, you may need to confirm port/channel mapping. A practical method is to test the expected RX/TX behavior in a terminal, rather than assuming the first port is always the correct one.
Specifications
| Product Title | waveshare USB to UART/I2C/SPI/JTAG Converter, Supports Multiple Interfaces, Compatible with 3.3V and 5V, Multiple Systems Support, Support Linux (Only for Raspberry Pi) |
|---|---|
| Category | Electronics > Computers & Accessories > Computer Components > Desktop Barebones |
| Brand | waveshare |
| Manufacturer | Waveshare |
| Model Number | USB TO UART/I2C/SPI/JTAG Converter |
| Item Weight | 0.16 Kilograms |
| Color | Green |
| Compatible Devices | Personal Computer |
| Connector Type | USB Type B |
| Number of Ports | 1 |
| Input Voltage | 3.3 Volts |
| Power Plug Type | No Plug |
| Smart Home Compatibility | Not Smart Home Compatible |
| Finish | Metallic Matte |
| Warranty Type | Limited |
| Package Quantity | 1 |
| Unit Count | 1.0 Count |
| Number of Items | 1 |
| Mfr Part Number | USB TO UART/I2C/SPI/JTAG |
| Finish Type | Metallic Matte |
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