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HomeMy DevicesSettings (DEMO-MERCURYPLUS)
Mercury Plus settings
Configure your devices settings here, please ensure it is turned on and connected to the internet
Need help getting your Mercury connected to WiFi? Our quick setup guide takes less than a minute to complete.
WiFi setup guide
It appears you have not yet calibrated your accelerometer and gyroscope. For the best and most accurate data you should do this periodically.
Calibration guide
Flight settings
Forecast pressure
Set this to your local forecast pressure at sea level. This will offer you slightly improved accuracty for your flight, although it's not 100% essential every little helps!

Xcweather.co.uk is a decent place to grab pressures from for your location and time.
mbar
Launch detect
This is the altitude change required to trigger launch detection and start recording. We suggest leaving it on 10 or 25 meters, although you can use a lower setting for low altitude rocket flights or testing the device by throwing it in the air. The lowest settings risk being triggered accidentally by gusts of wind on extremly windy days, although it's still fairly unlikely.
Sensor speed
The base sensor cycle rate. 100Hz gives double the data resolution during flight but uses slightly more battery. 50Hz is the power-saving option. The sample ratio below divides this rate for recording.
Sample ratio
Record every sample or every X samples to extend log time. Hybrid modes start at 1:1 then switch to a reduced ratio ten seconds after apogee to save storage while keeping full resolution during the active flight.
Max Samples
This setting will stop the recording when this number of samples has been reached. You may find this useful if you disable the auto stop function and want to limit the time of a recording.
Recording stop
The recording stop is how your altimeter decides when to stop recording. The 300 and 600 stable samples option are used to detect when the rocket has stopped moving for this many samples, it will then stop recording and save the buffers to the flash memory. If you prefer you can select Manual which requires you to push the button to stop the recording, or it will run until the 10200 sample limit.
Oversampling
The onboard BMP390 pressure sensor includes two internal filters, this is one of them and tells the sensor to take multiple sensor readings before ouputting the data. This increases precision and reduces noise, the 4X option adds two bits of accuracy to your readings and can still output data at 50Hz rate.
IIR filter
The IIR Filter is the second internal filter for the BMP390 pressure sensor. This is a Infinite Impulse Response filter and creates a recursive equation which uses both previous input and output samples. It results in removing noise and dampening sudden spikes in the pressure.
Pressure filter
This is a software filter on the altimeters microcontroller that offers a Kalman filter for processing the pressure data. This filter is a mathematical algorithm that estimates the correct value of the sensor over time based on previous measurements. It's excellent for dealing with noisy data and giving an expected true output.
Lockout time
Milliseconds to lock out apogee and landing detection and flatline altitude after a lockout trigger. Set to 0 to disable. Default: 500ms.
ms (0=off, default 500)
Lockout change
Altitude drop in metres per sample at 100 Hz that triggers a lockout. Automatically doubled at 50 Hz. Catches ejection charge events and supersonic transitions. Default: 1.00 m.
m (default 1.00)
Sync sensors
The filters on sensors can cause a small amount of delay that may not match other sensors. This setting will detect how far out of sync each sensor is with each other when launch is detected and re-synchronise them by adding calculated offsets based on the initial data.
IMU Filter
The fusion filter is how the altimeter works out it's orientation angles from the Accelerometer and Gyroscope readings. As the Mercury does not have a magnetometer we have to use 6DOF and some errors will build up over time while in flight. These filters along with the Gyroscope calibration help minimise these errors and give great results. 9 Axis options are disabled for the Mercury, our Neptune altimeter will support these.
Orientation
It is imporatnt that you mount your altimeter in one of these orientations if you want to record reliable and accurate angles from your altimeter. The default option is upright with the USB port pointing downwards. Please check the manual for more information.
Launch ALP
Accidental launch protection (ALP) helps to prevent accidental triggering of the launch. With this disabled the altimeter relies on just the pressure sensor and the altitude it indicates. The problem with this is strong gusts of wind, or pulling the nose cone off for example can cause a pressure drop that triggers the altimeter. The ALP requires 3 of the previous 8 samples to have acceleration magnitude greater than this setting to enable the launch detection to trigger. This prevents accidental triggering if the rocket is not also accelerating at the time it sees the altitude exceed the set level.
Launch lock
Startup lock prevents the altimeter from detecting a launch until this number of seconds has passed since you turn the device on. It's not needed typically and for most uses it's best to leave this set to 0.
seconds
Static temperature
The static calculation temperature has a default value of 15 degrees celcius. You can have the altitude calculated on a different ambient temperature if you choose by setting it here.
C
Temp sensor
If you have installed one of our external MT1 temperature sensors you can automatically use it's temperature at launch for calculating the altitude by enabling this setting. You can use this to log the temperature or also use the temperature at launch for altitude calculations.
General settings
Device TAG
Your device tag will be applied to flights when they upload, so you can change it as needed. You can then search for this tag on the Altimeter cloud.
Group
If you are flying for a specific reason or in a challenge you can select this setting. Any flights you fly will be added to these groups of flights when your altimeter uploads them to the cloud. The Device tag is a good option for general use too and can be searched for, this option will put flights into specific categories on the altimeter cloud for category browsing.
Device Language
This is the language set on your devices admin panel.
LED Brightness
The LED's can go quite bright on the Mercury. To save on power (and heat when they are always on in WiFi mode) you can use this setting to dim them.
Battery bar
The battery bar on revision2+ boards is always lit in WiFi mode but you can choose a few options when in flight mode.
1: Just the current battery level LED will blink.
2: Full battery LED blinking periodically.
3: Only show battery level when button is pressed briefly.
UART
With the UART output disabled(default) you can use the GP6 and GP7 pads as Servo outputs or standard outputs. If you enable the UART output then sensor data will be streamed using a UART on the GP6 and GP7 pads. You can then not use these pads for other uses.
GP6 = TX
GP7 = RX
Maintain power
After a flight is saved this sets what the altimeter does: Sleep after save = power down. Stay on = blink the apogee out on the status LED until you power-cycle. Show 5 min = blink the apogee for 5 minutes then sleep. Independent of eNOW below - if either is on the device stays awake, and it only sleeps when both are off. (Firmware 2.40+ required)
eNOW mini-chart
Broadcasts a downsampled altitude-vs-time flight profile over eNOW after landing, so a lost rocket's flight can still be plotted on the screen even if it is never recovered. Every mode sends 240 samples; higher rates cover a shorter window (2Hz=120s, 4Hz=60s, 8Hz=30s). Uses more power than tracking pings alone. (Firmware 2.40+ required)
eNOW: Enable
eNOW enables your Mercury to transmit pings for short range tracking including information such as your apogee and battery level after a flight is saved. It's range should be 80 to 300 meters depending on conditions and landing. (Firmware 2.2+ required)
eNOW: Interval
This is the interval that the Mercury will transmit it's pings at. The Mercury will sleep to preserve power inbetween pings. The minimum is 4 seconds so that several devices can share the air without their pings (plus random jitter) colliding. At 4 seconds it should last roughly 3 hours after your flight assuming it was fully charged pre-flight. (Firmware 2.2+ required)
eNOW: Startup
Broadcasts the most recent flight's summary and chart over eNOW a few times at power-on, so a paired screen can pull the last flight without a new launch. The radio powers down afterwards for normal flight/USB mode, so it adds a few seconds to boot when enabled. (Firmware 2.40+ required)
Smart power mode
Smart power mode
Power saving mode while waiting on the pad.

eMode 1 — Runs sensors at 50Hz and snaps to full speed on motion detect.

eMode 2 — CPU wakes at 25Hz and batch-reads IMU data from the sensor FIFO. Sensors stay at 52Hz in low-power mode. Halves CPU duty cycle for lower pad power. Battery bar is disabled and the status LED blinks every 8 seconds. Snaps to full speed on motion detect.
Gyro calibration
Calibrating your devices sensors should be done once you receive your device, it helps ensure the angles calculated during flight are as accurate as possible. Read the instruction page before calibrating.
Calibrate on save
Acc calibration
Calibrating your devices sensors should be done once you receive your device, it helps ensure the angles calculated during flight are as accurate as possible. Read the instruction page before calibrating.
Calibrate on save
Please read the manual page on how to complete calibration before doing it.
Manual: Calibrating sensors.

When you click save the selected calibration methods will start. The Gyro process will run first followed by the accelerometer process.
Current calibration values
Gyroscope
X
0.00 °/s
Y
0.00 °/s
Z
0.00 °/s
Accelerometer
X
0.00 mG
Y
0.00 mG
Z
0.00 mG
Apogee prediction
The Mercury can predict apogee while it coasts after burnout and report this on your charts, using the rocket parameters below. Firmware 2.1+ required.
Rocket mass
This is the mass of your rocket after burnout. So your complete as you fly rocket with a burnt out motor case loaded. For the most accurate prediction you need to get this as accurate as possible.
Kg
Drag coefficient
This is the drag coefficient for your rocket. It's likely to typically be somewhere between 0.5 and 0.75 with the latter being a good place to start. You may need to adjust this if you have significant inaccuracies in the prediction apogee compared to the real apogee on test flights.
Rocket area
This is the cross sectional area of your rocket as viewed from the top in meters squared (m^2). Again please try to be as accurate as possible for best results.
m^2
Calc air density
This setting calculates the density of the air at the rockets current altitude for the most accurate calculations. If you disable this it will use a static average of around 400 meters altitude. The static altitude should be mostly fine if you're flying below 1000meters.

IMPORTANT: You need to enter the accurate forecast pressure for the day and location you are flying for it to calculate your altitude above sealevel to use this function accurately.
Air gas constant
This is the gas constant for air. The default (dry air) is 287.05 J/(Kg.K), you would only want to consider changing this if you're flying in very damp air for example.
J/(Kg.K)
The mass, drag and area above feed the predicted-apogee calculation. Air brake configuration now has its own page: open the Air brake page →