UART-Hammer 🔨

A cross-platform Rust CLI to stress-test and benchmark UART/serial links.
This is still a work in progress, use at your own risk.

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Features

• Verify all known baud rates

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Install

# Clone and build with Cargo
git clone https://github.com/hammerlink/uart-hammer.git
cd uart-hammer
just build # this builds both risc-v & x86

🚀 Usage

You’ll need two devices (or two UART ports on the same machine). Run one side in auto mode, the other in test mode.

Example: Auto/Responder Mode

uart-hammer auto --dev /dev/ttyS1

Example: Baud Sweep Test

uart-hammer test \
  --dev /dev/ttyS1 \
  --bauds "115200,230400,460800,921600,1000000,1500000,3000000"

This will iterate through the listed baud rates, sending/receiving test frames and printing stats.

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⚙️ Options

Flag	Default	Description
--dev <PATH>	(required)	UART device path (/dev/ttyS1, /dev/ttyUSB0, etc.).
--tests <LIST>	max-rate,fifo-residue	Comma-separated test selection.
--bauds <LIST>	115200,57600,38400,19200,9600	Baud rates to test (comma-separated).
--parity <MODE>	none	Parity: none, even, odd.
--bits <N>	8	Data bits (e.g. 7, 8).
--dir <MODE>	tx,rx	Direction: tx, rx, or both.
--flow <MODE>	none	Flow control: none, rtscts.
--payload <BYTES>	32	Payload size per frame (bytes).
--frames <N>	200	Number of frames per test.
--duration-ms <MS>	(optional)	Run test for given duration (overrides --frames).

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📊 Example Output

# > uart-hammer test --dev /dev/ttyUSB1 --bauds "115_200, 230_400, 460_800, 921_600, 1_000_000, 1_500_000, 3_000_000"
[port] reconfigured to 115200 8-N-1-
[test] id=1c9ee05a-29e3-4576-bd4a-bc451731efdd awaiting slave
[test] got ACK from slave id=9e58663a-427d-422b-b30a-355566dcc529
[port] reconfigured to 115200 8-N-1-
[test] running test 'max-rate' dir=Tx at PortConfig { baud: 115200, parity: None, bits: 8, flow: None, stop_bits: 1 } 115200bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=91116 reason=none
[test] running test 'max-rate' dir=Rx at PortConfig { baud: 115200, parity: None, bits: 8, flow: None, stop_bits: 1 } 115200bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=91215 reason=none
[test] running test 'fifo-residue' dir=Tx at PortConfig { baud: 115200, parity: None, bits: 8, flow: None, stop_bits: 1 } 115200bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=91100 reason=none
[test] running test 'fifo-residue' dir=Rx at PortConfig { baud: 115200, parity: None, bits: 8, flow: None, stop_bits: 1 } 115200bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=91218 reason=none
[port] reconfigured to 230400 8-N-1-
[test] running test 'max-rate' dir=Tx at PortConfig { baud: 230400, parity: None, bits: 8, flow: None, stop_bits: 1 } 230400bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=180811 reason=none
[test] running test 'max-rate' dir=Rx at PortConfig { baud: 230400, parity: None, bits: 8, flow: None, stop_bits: 1 } 230400bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=180821 reason=none
[test] running test 'fifo-residue' dir=Tx at PortConfig { baud: 230400, parity: None, bits: 8, flow: None, stop_bits: 1 } 230400bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=180939 reason=none
[test] running test 'fifo-residue' dir=Rx at PortConfig { baud: 230400, parity: None, bits: 8, flow: None, stop_bits: 1 } 230400bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=180821 reason=none
[port] reconfigured to 460800 8-N-1-
[test] running test 'max-rate' dir=Tx at PortConfig { baud: 460800, parity: None, bits: 8, flow: None, stop_bits: 1 } 460800bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=354449 reason=none
[test] running test 'max-rate' dir=Rx at PortConfig { baud: 460800, parity: None, bits: 8, flow: None, stop_bits: 1 } 460800bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=355274 reason=none
[test] running test 'fifo-residue' dir=Tx at PortConfig { baud: 460800, parity: None, bits: 8, flow: None, stop_bits: 1 } 460800bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=356094 reason=none
[test] running test 'fifo-residue' dir=Rx at PortConfig { baud: 460800, parity: None, bits: 8, flow: None, stop_bits: 1 } 460800bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=355289 reason=none
[port] reconfigured to 921600 8-N-1-
[test] running test 'max-rate' dir=Tx at PortConfig { baud: 921600, parity: None, bits: 8, flow: None, stop_bits: 1 } 921600bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=689258 reason=none
[test] running test 'max-rate' dir=Rx at PortConfig { baud: 921600, parity: None, bits: 8, flow: None, stop_bits: 1 } 921600bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=686720 reason=none
[test] running test 'fifo-residue' dir=Tx at PortConfig { baud: 921600, parity: None, bits: 8, flow: None, stop_bits: 1 } 921600bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=691585 reason=none
[test] running test 'fifo-residue' dir=Rx at PortConfig { baud: 921600, parity: None, bits: 8, flow: None, stop_bits: 1 } 921600bps
[auto] PASS frames=200 bytes=19490 bad_crc=0 gaps=0 overruns=0 errors=0x0 rate_bps=686730 reason=none
[port] reconfigured to 1000000 8-N-1-
[test] running test 'max-rate' dir=Tx at PortConfig { baud: 1000000, parity: None, bits: 8, flow: None, stop_bits: 1 } 1000000bps
[test] max-rate test failed: running max-rate test
[test] running test 'max-rate' dir=Rx at PortConfig { baud: 1000000, parity: None, bits: 8, flow: None, stop_bits: 1 } 1000000bps
[test] max-rate test failed: running max-rate test