Sentinel Automatic Trigger System (SATS-MINI) Quick Start Guide and Resources

Use this resource to get started with the SATS-MINI

SATS-MINI Quick Start Guide PDF

SATS-MINI Product Guide PDF

SATS-MINI Users and Programming Guide PDF

Software Downloads - Current latest version is 1.0.27

Download Version 1.0.27 (Beta 1) - Current Version

Past Versions


IMPORTANT - READ FIRST FOR SATS_MINI NEW CUSTOMERS - We always ship the SATS-MINI pre-loaded with the latest software available and with the default configuration.  If you ordered the SATS-MINI as part of a bundled product, like the Inspire 2 or Mavic 2 parachute the SATS-MINI comes pre-set with the Z axis orientation set. Also the channels come pre-configured for proper operation.  Before flight do charge the SATS-MINI via the USB port. We DO recommend through ground  testing befor flight to validate operation. See the instructions below for basic operation. If you have any questins about the device please contact us!

Get Started Here

Here we give you the most important information you need to get up and going fast. Much of this information here is also covered in the SATS-MINI Product Guide and the SATS-MINI Users and Programming Guide so be sure to refer to these for more detailed information.

The Sentinel Automatic Trigger System (SATS-MIN) has many complex programmable features that can be setup using the ShootyChute Windows UI program. Once the configuration is uploaded the only thing you need to do to fly and protect your drone is to turn on the SATS-MINI. Also before you fly be sure the SATS-MINI is in the operational Safety / Armed state so the parachute can trigger. After flying disarm the SATS-MINI and power down. Later you can download your flight log to your PC using the Shooty Chute app. If you parachute is needed the flight log becomes an essential part of diagnosing what the failure is.

Preloaded Default Configuration

The SATS-MINI comes preloaded with a default configuration that will work for most drone applications. In this configuration the channels are programmed as:

Channel 1 - Trigger, Trigger output, PWM, servo sweep 45 degrees to 135 degrees, no delay, 5V Power Out - Use this channel for the Harrier or other launcher that needs a servo PWM signal

Channel 2 - Trigger Delayed, Trigger Output, PWM, servo sweep 45 degrees to 135 degrees, 500ms delay, 5V Power Out - Use this channel for your PWM output if you want to delay the parachute trigger. In that case you would use Channel 1 for Flight Termination, then Channel 2 to eject the parachute 500ms later.

Channel 3 - Skycat V3 Trigger, Trigger Output, PWM, servo sweep 45 degrees to 135 degrees, no delay, 5V Power In - This channel is preconfigured for the Skycat V3 trigger. Channel 3 can accept power in from the V3 Trigger. And at the same time this channel will provide the PWM output to launch the parachute.

Channel 4 - Nano RX, Trigger Input, PWM, Trigger PWM 2000us, 10% Tolerance, 5V Power In - The optional TBS Nano receiver, if installed, will use this channel in order to provide an PWM trigger signal so you can remote eject the parachute from the Skycat rescue radio. If the Nano is not installed then you can use Channel 4 for any other virtual IO feature.

Failure Detection Settings used to trigger the parachute are defaulted to:

  • Tumbling (Non-Primary Axis) - 360 degrees roll in under 2 seconds
  • Yaw (Primary Axis) - 540 degrees rotation in under 2 seconds
  • Free Fall - Accelerometer fused X/Y/Z magnitude threshold <= 0.3G for >= 0.5 seconds

These settings will work for most all drones like the Mavic 2, Phantom 4, and other DJI drones. The settings will not result in false triggers for normal flying conditions.

To change the settings use the ShootyChute Windows UI to edit the configuration. See the SATS-MINI Users and Programing Guide for details how to use the program.

SATS-MINI Basic Operation

Below is a renerding of the SATS-MINI case and the various features.

To turn on the SATS-MINI press and hold the System Mode button for 2 seconds. Once the indicator lights come on release. The SATS-MINI will come up in the same System State it was in when powered down. The mode light may temporarily show solid Purple if there is a startup process that needs to happen before going to the operational state. In rare cases it can remain solid Purple for several minutes so just wait.

To Turn Off the SATS-MINI quickly press and release the System Mode button. The SATS-MINI will beep twice, high then low. After that press and hold for two seconds. The SATS-MINI will do a Triad of beeps and turn off.

To change SATS-MINI operational states press and hold the System Mode button for 1 second and it will transition between operational states. The beeper will also sound.

Install ShootyChute Windows UI

1 - Download the SATS-MINI Windows UI software from our website (link on this page).

2 - Double click on the ShootyChutes.msi file and follow the steps. Windows will complain that the publisher is unknown. Click the links to force Windows to install the software. Tou will need to agree to the End User License Agreement.

Using ShootyChute

1 - First plug in the SATS-MINI USB port to your computer first so the COM port is created. This will also turn on the SATS-MINI.

2 - Start ShootyChute.

3 - The serial port of the SATS-MINI should be listed. Click Connect. The box next to Connect should turn Green.

4 - Physically moving the SATS-MINI should cause the 3D box rendering to track the movements.


NOTE: If the SATS-MINI does not have a valid configuration then the Status LED will pulse PURPLE. In this case you need to send a default configuration to the SATS-MINI and restart. To do this use Tools - Send Default Configuration. After restart the status LED will flash Green and the UI Drone will track the movement of the SATS-MINI. In some rare cases with a software upgrade you may need to use the tool “Reset to Factory Defaults”. The software release will indicate when that is needed.

Updating the Firmware

The SATS-MINI is always shipped with the latest firmware softweae. When new versions are available the firmware installs for the SATS-MINI are formatted as a self installing UF2 file format. In order to install:

  1. Power up the SATS-MINI and connect the USB cable. You should hear the beep that the USB port is recognized. 
  2. Before you start make sure the SATS-MINI is in the Idle state, the green light should be flashing which is Idle.
  3. To load the firmware use a paper clip of other small tool and press the reset button twice within 1 second or less. There is an access hole in the SATS-MINI case to reach the Reset button. This will put the SATS-MINI into the Bootloader mode and a Drive letter will show up in your Windows File Explorer that says FEATHERBOOT. The status LED will also pulse red. 
  4. Open up the folder. Drag the firmware-<date>.UF2 file into the folder and you should see the red light flicker and the SATS-MINI restart. 
  5. The green idle light will start to flash and the SATS-MINI with be in Idle.

NOTE: Some firmware upgrades require you send a new default configuration to the SATS-MINI due to new features being supported. You should also erase the Log file before going to armed in case there are changes in the Log format..

To Configure the SATS-MINI

1 - After connecting click Tools - Device Setup. The current setup for the SATS-MINI will be pulled down. 

2 - If you have installed new Firmware be sure to send a new Default Configuration to the SATS-MINI in case the configuration format has changed.

  1. If you have a setup you would like to save you can first save that your local hard drive. 
  2. Then update the configuration of the SATS-MINI by sending a new default configuration - Tools - Send Default Configuration. 
  3. After you send the config power cycle (or reset) the SATS-MINI. 
  4. Reconnect and then load your saved configuration from disk and upload to the SATS-MINI. Also recalibrate the SATS-MINI orientation (see below).
  5. Power Cycle (Reset) one more time and saved config and calibration will take effect. 
  6. It’s also best to clear out the Logs in case any format changes have been made. To do this use Tools - Erase Log

IMPORTANT - Do not use “Send Default Config” unless you have done a firmware update that requires this. If you do need to reset the config you can save your setup first to your hard drive. After the upgrade you can connect, load your config and push that back to the SATS-MINI.

3 - You can now do any other configuration items needed at this time. After making a change be sure to upload to the SATS-MINI and restart the unit.


NOTE: Be sure to ground test any updated you make. It’s less expensive to discover setup issues on the ground rather than in flight!

SATS-MINI Calibration

In order to optimize the SATS-MINI detection algorithm you need to tell the system which way is up. The calibration procedure allows you to mount the SATS-MINI on your drone in any imaginable orientation and it will work the same. Follow these steps:

  1. Mount the SATS-MINI on your drone. Any orientation is Ok.
  2. Turn on the SATS-MINI and first initialize the IMU magnetometer by rotating the SATS-MINI (or rotate your drone) a few rotations around all three axis. The internal Co-processor will then learn the position of magnetic north. If you have a large drone it may be easier to detach the SATS-MINI and rotate it on it’s own, then reattach.
  3. This next step is optional and is not required for proper SATS-MINI operation. In order to have the SATS-MINI exactly track your drone movement so the ShootyChute animated UI drone matches the physical drone movement you will want to orient your drone to face magnetic North. If you have a cell phone compass, or a tool like GPS Essentials it can tell you which way to point your drone. 
  4. Next put your drone in a level position (optionally facing magnetic north) so we can capture the physical SATS-MINI orientation. In the UI go to Tools - Device Setup. Click Acquire in order to capture the raw IMU orientation. You will see angle values populate the X / Y / Z fields. Clicking acquire again should result in consistent values.
  5. Upload that to the SATS-MINI and restart the SATS-MINI.
  6. Reconnect the UI and the SATS-MINI and the UI drone should appear level and the drone arrow will face away from you. If you did step #3 your movement of the drone tilting will be exactly matched by the UI Drone. Also it’s key that the IMU is internally calibrated (step 2). If it does not face away from you the the IMU manetomers may not have been completely settled when you acquired the position. Repeat the calibration process if needed. In any case the Z axis will be very close to optimal for the detection algorithm to work properly after calibration.

SATS-MINI Log Log File

When the SATS-MINI is armed trigger events and flight data are logged to the onboard Flash memory. The Flash memory will hold approximately 5 hours of detailed log data. After this only critical events are logged. To dump the log:

1 - Click Tools - Dump Log.

2 - Enter the file name to save to. The dump is in CSV format.

3 - Click Save. The message box will tell you once the dump is completed.

After dumping logs are not deleted. Instead new logs are appended and a new log number assigned. You can erase the log using Tools - Erase Log.

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