EasyMini Altimeter Setup and Deployment Guide

Quick Answer

For reliable dual deployment in high power rockets, set up the EasyMini altimeter by wiring the e-matches correctly, programming it with AltosUI, and verifying with a bench test before every flight.

Step-by-Step Setup and Deployment

1. Wire the e-matches: Connect one e-match to the apogee output and one to the main output. Ensure the main charge fires at the programmed descent altitude, typically 300-500 feet. Use twisted pairs or proper wiring to avoid shorts. Common mistake: mixing up the two outputs, which causes the main to deploy at apogee. Check continuity with a multimeter before closing the av-bay. Label your wires clearly to avoid confusion at the pad.
2. Power the altimeter: Connect a fresh 9V battery to the data strip or a charged AltusMetrum LiPo to the dedicated port. The EasyMini has two battery ports: the special connector for LiPo and the data strip for 9V. Do not connect both at the same time. Common mistake: using a weak battery, which can cause brownouts during ejection. Verify the battery voltage reads above 8V for a 9V battery. Always test with the exact battery you will fly with.
3. Program with AltosUI: Plug in the USB cable and launch AltosUI. Read the device, set the main deployment altitude (e.g., 400 feet), and configure the apogee delay if needed. Use the flight simulator to verify your settings. Common mistake: forgetting to set the main altitude, leaving it at zero, which disables main deployment. Save the configuration and confirm the device reboots with the new settings. Double-check the main altitude is non-zero before closing the av-bay.
4. Perform a bench test: With e-matches installed, simulate a flight by pressing the test button or using the AltosUI ground test. Watch for the apogee output to fire, then the main output after the programmed delay. Common mistake: testing with live e-matches without proper safety, which can cause accidental ignition. Use a test resistor or dummy loads if available. Never bench test with live e-matches in a confined space.
5. Install in the rocket: Mount the EasyMini in the av-bay with foam or padding to protect it from shock. Ensure the barometric sensor ports are exposed to the outside air through a vent hole. Common mistake: sealing the av-bay completely, which prevents pressure changes and causes false apogee readings. Drill a small vent hole (1/8 to 3/16 inch) in the av-bay tube. The vent hole must be clear of tape and debris.
6. Launch day check: Before loading the rocket on the pad, power on the EasyMini and listen for the beep pattern that indicates readiness. Confirm the battery voltage and that the e-matches show continuity. Common mistake: forgetting to arm the altimeter by powering it on after connecting the igniter, which can cause a no-deployment event. Always power on and verify the beeps before leaving the pad area. Make a pre-flight checklist and follow it every time.

Product Facts

• Altus Metrum EasyMini Altimeter: The EasyMini uses a barometric sensor to determine apogee and descent altitude, and has a built-in Micro USB port for direct computer connection. You can program and read flight data without extra hardware, and the barometric sensing gives you precise deployment events for dual deployment.