Writing requires a licensed copy of FSUIPC (to prevent abuse). Here’s how to set the autopilot altitude:
import fsuipc
import struct
fs = fsuipc.connect()
This script logs position, altitude, and speed every second, then plots the flight path.
import fsuipc
import time
import csv
import struct
from datetime import datetime
fs = fsuipc.connect()
log_filename = f"flight_log_datetime.now().strftime('%Y%m%d_%H%M%S').csv"
with open(log_filename, 'w', newline='') as csvfile:
writer = csv.writer(csvfile)
writer.writerow(["timestamp", "lat", "lon", "alt_ft", "ias_kts", "vs_fpm"]) fsuipc python
try:
while True:
# Read multiple offsets at once (efficient)
lat_raw = struct.unpack('i', fsuipc.read(0x0574, 4))[0]
lon_raw = struct.unpack('i', fsuipc.read(0x0578, 4))[0]
alt_ft_raw = struct.unpack('i', fsuipc.read(0x0570, 4))[0] # altitude in feet
ias_raw = struct.unpack('H', fsuipc.read(0x0B70, 2))[0] # *128
vs_raw = struct.unpack('h', fsuipc.read(0x07C8, 2))[0] # vertical speed * 60.48
lat = lat_raw / 1e7
lon = lon_raw / 1e7
alt_ft = alt_ft_raw
ias_kts = ias_raw / 128.0
vs_fpm = vs_raw * 60.48 # convert to feet per minute
writer.writerow([time.time(), lat, lon, alt_ft, ias_kts, vs_fpm])
csvfile.flush()
time.sleep(1)
except KeyboardInterrupt:
print("Logging stopped.")
fs.close()
While pyfsuipc is excellent, here are other Python-FSUIPC approaches:
For most users, pyfsuipc offers the best balance of simplicity and power. Writing requires a licensed copy of FSUIPC (to
For decades, serious flight simulation enthusiasts and add-on developers have relied on FSUIPC (Flight Simulator Universal Inter-Process Communication) as the ultimate bridge between external applications and Microsoft Flight Simulator (FSX), Lockheed Martin Prepar3D (P3D), and now Microsoft Flight Simulator 2020/2024.
While FSUIPC is traditionally accessed via Lua scripting or C/C++, the combination of FSUIPC with Python opens up a world of possibilities — from building custom cockpit instruments to automating flight tests, logging telemetry, or creating AI-driven copilots.
In this comprehensive guide, you will learn:
# Write a value to the aircraft's altitude
ipc.write('Altitude', 10000, fsuipc.FLOAT)
Reading offsets one by one is slow. Use fsuipc.read_multiple(): While pyfsuipc is excellent, here are other Python-FSUIPC
import fsuipc
import struct
fs = fsuipc.connect()
offsets =
0x0574: 4, # lat
0x0578: 4, # lon
0x0570: 4, # alt
0x0B70: 2, # ias
data = fsuipc.read_multiple(offsets)
lat = struct.unpack('i', data[0x0574])[0] / 1e7
1. Direct Memory Access (The "God Mode")
The primary strength of using Python with FSUIPC is the depth of control. You aren't just pressing buttons; you are manipulating memory offsets. If the simulator tracks a value (from the battery voltage to the exact position of a flaps lever), you can read it. This allows you to create custom logic that the default simulator doesn't support. For example, you can write a script that says: "If the battery voltage drops below 24V and the engines are off, automatically trigger a master caution light."
2. Hardware Integration Potential
This is where FSUIPC Python shines for cockpit builders. While hobbyists often use Arduino or Raspberry Pi for physical switches and LEDs, they need software to bridge the hardware to the sim. Python scripts utilizing FSUIPC are the perfect "glue." You can write a script that reads a toggle switch connected to a Raspberry Pi GPIO pin and sends that command directly to the simulator via FSUIPC instantly.
3. Speed and Efficiency
Python is an interpreted language, but the libraries used (like pyuipc) are wrappers around C/C++ DLLs. This means the communication is surprisingly fast. For reading simple data like airspeed or heading, the latency is negligible, making it suitable for real-time instrument feedback.
4. The Ecosystem
Because Python is the standard language for data science and automation, the ecosystem is massive. Once you have your data from FSUIPC into Python, you can log flights to Excel, upload data to a web server, display it on a touchscreen using Kivy or Tkinter, or process it with AI models. No other scripting method offers this breadth of possibility.