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Roman Vojtech
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ALTI 2 also known as LOLO2 (A2/L2). A2/L2 is successor of LOLO/LOLO RACE - 26/10/03 (Not produced anymore)
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Overview
The ALTi2 is a Digital Recording Altimeter that enables you to store and retrieve an altitude profile of your model or activity for later download and analysis. ALTi2 measures changes in pressure, at a pre-determined sampling rate that is selected by the user, and stores the results in its on-board memory.
The data is then downloaded to your PC using our ALTi2 Analysis Software which then converts the pressure readings to altitude. There are 4 sampling rates possible as shipped (0.1, 0.2, 0.5, 1.0 seconds) and, with a minor modification a 2nd set of different rates (0.2, 1.0, 2.0 and 6.0 seconds) is available.
The sampling rate is selected via a small DIP switch located just inside the open end of the ALTi2 case. The maximum memory capacity of ALTi2 is 2hours 16 minutes when a 1-second sampling rate has been selected. When a 6-second sampling rate is used, the capacity is more than 13 hours, and when using the ALTi2 BF version more than 2 days (52 hours) of storage are available!
Device memory area is separated into individual data recording sessions-flights which are created automatically each time device is switched ON. Each flight is independent in length, storage period and altitude data. As an example: You can have one session of your trip to the flying field, then several sessions of flights, and another session of your return trip home. Once at home (or if you have a notebook PC) you can download ALTI2 sessions to your PC for processing and analysis.
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Technical Specification
Standard & BF
- Dimension L38xH13xW18 mm (L1.49xH0.5xW0.7 inch.)
- Weight 9g incl. 150mm JR/Graupner cable
- Sampling rates. Using DIP switch you can choose requested sampling rate.
Standard: 0.1sec (14min), 0.2sec (28min), 0.5sec (1h:8min) and 1.0sec (2h:16min). There is also available second set of sampling rates 0.2, 1.0, 2.0 (4h:32min) and 6.0sec (19h:36min) but needs some tiny hardware hack. See HW hack
BF has four times bigger memory: 0.1sec (45min), 0.2sec (1h:52 min), 0.5sec (4h:32min), 1.0sec (9h:4min). There is also available second set of sampling rates 0.2, 1.0, 2.0 (18h:8min) and 6.0sec (54h:30min) but needs some tiny hardware hack. See HW hack
- Total memory capacity 8 180 records in Standard version and 32 720 records in BF version
- Power 4.4-9.6 Volts DC
- Current consuption 15mA
- Resolution 0.5m (don't mix with accuracy)
- Maximum altitude (recommended) 3000 m (9.843 ft). This limit is relative i.e. if you switch ON in 2000m you can go up to 5000m. Above relative 3000m limit A2 also works and measures, but accuracy of used pressure/altitude equation is already questionable. See also Q&A.
- Number of Flights (ON/OFF cycles), not limited
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Button cable
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RS 232 (Serial) cable with Clear Memory button
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USB/RS232 Adapter
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System Requirements
Alti2 as is supplied connects ONLY to RS232 interface i.e. serial port (aka COM1, COM2,...). If you want to connect it via USB port to your computer you will need optional USB/RS232 Adapter. This is also available see Price.
Supplied software was tested on Windows 98SE/2K/ME/XP. This software does NOT work under any other system.
If you want to run A2 on different operating systems you need download data and recalculate them. Please keep in mind there are two problems reading data from A2:
- Hardware problem-if your computer has RS232 port you can communicate with A2 straight away using any program handling your RS232 port (usually terminal emulation). If you have only USB connector here USB/RS232 adapter helps you. For adapter there are drivers for Windows 98SE/2K/ME/XP, Linux, MacOS 9 family and MacOS X.
Ok, let's say we solved hardware connection between A2 and your computer, for example at Apple Macintosh using mentioned USB/RS232 adapter and corresponding driver (piece of software supplied with adapter) in this case Mac OS X.
- Software problem-as it's written above, supplied software works only on Windows 98SE/2K/ME/XP. If you want to watch your altitude logs on different than Windows 98SE/2K/ME/XP system you need software which recalculates data downloaded from A2 to altitude and displays it for you. My software makes it all in one step-download and recalculate.
- Data from A2 do NOT show altitude directly, you have to recalculate it (this makes my software for you). Data structure you can see at A2 Data Structure Definition.
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Installation
Alti2 is very small device and alllows you to use it nearly in all aplications. It uses very precise atmospheric air pressure sensor, you should let surrounding atmosphere to reach your A2. I use it in F3B/F3F models where canopy, wing and fuselage fits very tight, but are not evidently hermetic while A2 works.
Respecting A2 is actually air pressure looger (formula calculating altitude is in your PC) you should consider placing it in environment where "sucking" or "pressure" efects are minimal. Otherwise results can be dependent forexample on speed of your aircraft. Always think twice and take in account this facts especially when evaluating some strange looking altitude log results.
It's digital device, microprocessor is inside (and X-tal), you should avoid to place it just no-gap sideaway of other RC components (receiver, servos, gyros etc.). In F3X machines there is never plenty of room anyhow I never experienced any problem.
Some other hints for A2 instalation:
- Install ALTi2 as far as possible from high current wires
- Power spikes may affect altitude readings and proper operation of the ALTi2 is guaranteed only when supplied with power free from any interference
- If the power source of your model is not appropriate for the altimeter please use a separate power source. A good choice is a 4.8V 110mAh capacity pack, which should be sufficient for 5 hours of continuous operation.
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F3B BigSting A2 installation
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F3B Caracho A2 installation
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If you want to have full controll of your A2 you have to connect it to free receiver (Rx) output/channel which you will control using transmitter (Tx). It allows you to
- switch it ON (from standby mode)
- place Markers M1,M2,...Mx) in altitude log
- switch it OFF to spare A2 memory
If you will connect A2 to standalone DC source (4.4-9.6V) i.e. no signal from Rx*, it will start logging automatically after 120sec. It can be used for outdoor activities etc.
*If you will connect A2 to any Rx output (although NOT controlled) it will NOT start log automatically, there is always on Rx output some signal. A2 will be in stand by mode waiting for signal change from Tx. If you don't want to use standalone DC source (you want to power A2 from Rx) don't connect signal pin (orange color on provided JR /Graupner connector) of A2 and signal output of your Rx.
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Clearing Memory
Before first use clear A2 memory. Same procedure you have to do always when you want to clear (empty) your A2 memory. You will clear all recorded loggs.
- Disconnect A2 from power (switch OFF your Rx)
- Connect interface cable to A2
- Keep pressed Clear button on interface cable
- Connect A2 to power (switch ON your Rx)
- After 1-2sec LED wil start to blink, A2 memory is cleared, release Clear button
- Disconnect A2 from power (switch OFF your Rx) and interface cable, A2 is ready for new logs
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Logging (Three Operation Modes)
ALTi2 is operable in 3 modes:
- Transmitter Controlled – ALTi2 is connected to your Rx with a Signal lead and, using your transmitter, you can initiate data logging upon request, at any time, from your transmitter (using any channel or switch/button). You can also enter signal input Markers that will “mark” that point in the data as a significant event. A Marker is initiated by the same stick or switch/button movement you use to start logging. The Markers appear in the ALTi Analysis Software as points M1, M2….Mx.
For controlling A2 there are two levels of Tx signal neccessary. It corresponds to servo deflection -100% and +100% (MIN-MAX). Don't let controlled channel to be somewhere in between of these two levels, undefined results can occur.
After switching Rx ON, LED on A2 is indicating channel status; LED is slowly FLASHING-channel is in MIN (-100%) position, LED is ON-channel is in MAX position. You can reverse it using your transmitter (Tx) if it has such functionality.
For altitude logging start you need to switch over channel status (MIN-MAX-MIN or MAX-MIN) using any controller on your transmitter (stick, switch, potenciometer, button). Allow at least 1sec interval between position MIN-MAX-MIN (keeping stick, switch on transmitter in position MAX 1sec).
When A2 is logging altitude you will see very short flash (0.25sec) of LED in interval of choosen sampling rate. Every next channel full deflection (MAX, +100%) logs Markers (M1, M2,...Mx) in your altitude log. It allows you to see them in provided software after download for later analysis purpose.
You can stop logging also using Tx. If you keep controlled channel status in MAX(+100%) for more than 6sec A2 will stop logging. This feauture is just for preserving your memory in A2. LED is ON (no blinking) in this hybernated status (its NOT stand by status). You can NOT switch ON (to logging mode) A2 from this status using Tx again. You have to switch power for A2 OFF and ON.
- Transmitter Independent - ALTi2 is connected to your Rx with the Signal lead (Orange lead on JR/Graupner connector) deactivated and, after a 120 second initialization phase, starts automatic data logging at the sampling rate specified and there are no data “Markers”.
- Non-R/C – ALTi2 is NOT connected to an Rx but is instead connected only to an appropriate power-source and will respond the same as if installed Transmitter Independent. The difference being that there is no Signal lead to be deactivated.
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Software and Downloading Data
Download software and follow installation instructions ALTI.EXE 4,2MB ver. 1.0.24 (29/03/2004)
There are altitude loggs in A2 memory which you would like to analyse. After you installed software in your PC you can download data.
- Switch OFF power for A2
- Run programm Alti.exe
- Select Data, Read Data (CTRL+R), window "Waiting for Data" pops up.
- Connect Interface cable and switch ON power for A2, download starts automatically (LED of A2 is ON during sending data to PC, OFF when all data are sent)
- If there are more than one Flights (Cycle A2 power ON/OFF is treated as ONE flight) you will be asked if you want to save it as one Session (more Flights in one Session) or every single Flight as one Session (one Flight in one Session). Select OK, your data are displayed.
- Download is finished, disconnect A2 from interface cable and power
- Analyse your Data
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