MicroTrak AIO Testing

After configuring the MicroTrak, we took the device outside of Strong Hall to see if we could get a signal at the ground station, which was positioned just inside of the building by an open window. The MicroTrak auto transmitted every two minutes and gave us a position of right outside Strong Hall, as expected. The position was also recorded on the APRS website with Google Maps as shown below. We used the call sign KD8WQP.

Secondary Tracking System

We will be using a Micro-trak AIO as our secondary tracking system. It is powered by 8 AA batteries and comes with an SMA antenna.

We had to install the drivers from the Byonics website and configure the Micro-trak to the port "COM8". We are currently using Dr. Pawlowski's callsign in the primary configuration tab, which will be changed to David's callsign once it shows up on the FAA website. It is configured to auto transmit every 2 minutes and manually transmit every 30 seconds. We also changed the status text to something unique, specifically "Enterprise Logistics MT-AIO". Once everything was set, we wrote the configuration to the device. The Micro-trak is now ready to be tested.

Data Logger Test

We will use an OpenLog DEV-09530 MicroSD data logger to record the data collected by the sensors on the payload.  Upon powering up, this device will log data it receives, in this case through the Arduino's serial pin out (TX1) through the data logger's RXI pin and record the data to a micro SD card.

We found that no modifications to code used to communicate with sensors was needed--the Openlog automatically names a file and writes to it.  The below setup was used to test the Openlog.

Magnetometer Test

We will use a Triple Axis Magnetometer Breakout - HMC5883L to detect magnetic field at the payload's location during its flight.  The magnetometer provides a digital signal representative of magnetic in three axes, and must be provided with 2.16V to 3.6V.

We used the setup below to test the magnetometer.  We uploaded code to put the data from the magnetometer out through the serial monitor, and found that the sensor is responsive to the presence of refrigerator magnets. 

Accelerometer Test

We will use a Triple Axis Accelerometer Breakout - ADXL335 to detect the acceleration of the payload during its flight.  The ADXL335 provides three analog voltages corresponding to acceleration in each axis, and must be powered by a voltage between 1.8V and 3.6V. 

We used the setup below to test the accelerometer.  We created code that would read voltages in from pins A1, A2, and A3, and ran the code on the setup.  By aligning each axis in turn with g, we could find the base voltage out as well as the voltage given at 1g. 

We found that the voltage regulation on the Arduino is unreliable, giving different voltages at its 5V and 3.3V out pins depending on whether USB powers it or a 9V battery.  These voltages affect the voltages in from the accelerometer, and the conversion to real units , so in order to get accurate acceleration data, it will be necessary to configure the code with the final payload setup.

Pressure Sensor Test

We will use an MPX5100A-ND analog pressure sensor to detect atmospheric pressure at the payload's location during its flight.  This pressure sensor sends a voltage corresponding to pressure to the Arduino, and should be supplied with 5V.

We used the setup below to test out pressure sensor.  We created code that would read in a voltage from pin A0 repeatedly.  The datasheet provided for teh MPX5100 series gave a function to interpret the voltage as a real pressure, which when applied, gave us a reading of 99 KPa, close to the 1 atm expected.

Temperature Sensor Test

We will use two Digital Temperature Sensor Breakout - TMP102s, found here, to detect the temperature of the payload during its flight.  The TMP102 sends a digital signal representing temperature to the Arduino, and must be supplied by regulated voltage between 1.4V and 3.6V. 

We used the setup pictured below to initially test our TMP102.  After determining the correct serial port to use under Tools > Serial Port, we uploaded code to the Arduino.  We opened the Serial Moniter to view the temperature data from the TMP102, and verified its responsiveness to a change in temperature by touching the Temperature Sensor.

Arduino Test

We will use an Arduino Nano to interpret the sensors' and GPS's data, send the data to the data logger, and control the camera servo, communication system, and flight termination unit.

The Arduino Nano, described here and pictured below, provides 3.3V and 5V regulated power, and can be powered by 6-20V externally.

In order to use the arduino nano, we downloaded the arduino software from here.  We installed both the software and appropriate drivers to our respective operating systems, then opened the software.

Before connecting the arduino, we selected the "Arduino Nano w/Mega 328" under Tools > Board.

We began testing the arduino by using the example sketch "blink" to cause an LED to turn on and off.  Our next setup modified the code to make 10 LEDs to blink in sequence.