ppk2-mcp

MCP server for Nordic Semiconductor's Power Profiler Kit II (PPK2). Provides 12 tools for discovering, connecting, configuring, and measuring current draw directly from Claude Code or Claude Desktop.

Features

• Discover PPK2 devices on USB
• Connect with automatic calibration loading
• Configure source/ampere mode and supply voltage
• Measure current at ~100 kHz native sample rate
• Log raw measurements to timestamped CSV files
• Inspect saved logs without leaving the conversation

Requirements

• Python 3.10+
• Nordic Semiconductor PPK2 hardware
• USB connection to PPK2

Quick Start

git clone https://github.com/Ultrahuman-tech/ppk2-mcp.git
cd ppk2-mcp
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Then configure your MCP client (see below).

Configuration

Claude Code

Add to ~/.claude.json under mcpServers:

{
  "mcpServers": {
    "ppk2": {
      "command": "/path/to/ppk2-mcp/.venv/bin/python3",
      "args": ["/path/to/ppk2-mcp/ppk2_server.py"],
      "type": "stdio"
    }
  }
}

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "ppk2": {
      "command": "/path/to/ppk2-mcp/.venv/bin/python3",
      "args": ["/path/to/ppk2-mcp/ppk2_server.py"]
    }
  }
}

Replace /path/to/ppk2-mcp with the actual clone location.

Tools Reference

Tool	Description
list_devices	Scan USB for connected PPK2 devices
connect	Connect to a PPK2 and load calibration (returns session ID)
disconnect	Disconnect, stop measurement, power off DUT
set_mode	Set operating mode: source (PPK2 powers DUT) or ampere (external power)
set_voltage	Set supply voltage in mV (source mode only, 800-5000 mV)
power_control	Toggle DUT power on/off
get_session_info	Show current session state
start_measuring	Begin continuous current measurement
stop_measuring	Stop continuous measurement
measure	Atomic: start, collect for N seconds, stop, save CSV, return stats
list_logs	List saved measurement CSV files
get_log	Read a saved log file (metadata + first N rows)

Typical Workflow

list_devices          → find PPK2 on USB
connect               → get session_id
set_mode "source"     → PPK2 supplies power
set_voltage 3300      → 3.3V to DUT
power_control "on"    → power up the device
measure 5.0           → capture 5 seconds of current data
disconnect            → clean up

Logs

Raw measurement data is saved to the logs/ directory as timestamped CSV files. Each file contains:

• Comment header with metadata (date, duration, mode, voltage, sample count, sample rate)
• CSV data columns: sample_idx, current_ua (optionally digital for digital channels)

Example:

# PPK2 Raw Measurement Log
# Date: 2025-02-18 19:57:00
# Duration: 2.01s
# Mode: source
# Voltage: 3300 mV
# Samples: 200,544
# Sample Rate: 99,773 sps
sample_idx,current_ua
0,1523.45
1,1518.22
...

Known Issues

• Stale serial buffer on reconnect: After a previous session crashes or is interrupted, the PPK2's serial buffer may contain leftover binary measurement data. The server handles this automatically by flushing the buffer before reading calibration data.
• Metadata decode errors: The upstream ppk2-api library can crash on binary noise in the serial buffer. This server includes a built-in patch (latin-1 fallback) so no manual library edits are needed.

License

MIT - see LICENSE.