Self made data-logger V2.5 (second edition) (gehe zur deutschen Version)


An instuction for the construction of the older data-logger is to be found here:
(also information for additional sensors available, unfortunately only in german)

(last modification: 04.06.2005)
The new data-logger software is not yet completely finished.
But the hardware design is frozen and will probably not be changed anymore.
The printed circuit board is a bit smaller than the old one (36x22mm).
But unfortunately the new one can measure analog input signals only with 10 bit resolution.

The sensor for barometric altitude and its amplifier are contained on the printed circuit board now.
Since the dissolution of altitude (10 bit) is too rough for the climb rate, an additional circuit is on the board.
An amplifier for current measurements as well as an amplifier for measuring bridges are likewise contained on the  board.
Thus only an additional shunt or a measuring bridge (e.g. a differential pressure sensor with pitot tube) needs to be attached.
The measured data can be stored in a EEPROM and / or transferred by telemetry or by cable to a PalmPilot or PC.
The baud rate for the telemetry mode is selectable. 1200 and 9600 baud are available.
The data rate for the transfere of the the stored data to the Palm / PC was increased to 38400 baud.
Version V2.5 are different to version V2.4 in case of the circuit for current measurement. Therefore BEC-systems can used now.
Version V2.9 supports also GPS-receiver with ANTARIS chipset and simultaneously using of internal temperature sensor of MS5534A and external DS1820 sensor. This version can use 24C256, 24C512 or 24C1024 EEPROMs and has an internal 'bootloader' implemented.
With V2.9g you can configure the datalogger for the 'Multilogging mode' (more than one loggs possible after switch off).
V2.9h supports DS18S20 temperature sensors, 2-wire connection for the temp sensor (connect pin1 and 3 of the sensor) and better start condition for GPS using.

Telemetry Display

schematic V2.5c:
layout V2.5c:
part place V2.5c:
partlist V2.5:

following the old data:
schematic V2.4:
layout V2.4:
partlist V2.4:

Additional sensors:


Layout for LTC2400:
Layout for ADXL202:
Layout for TIM:

Following a modified circuit for the current measurement:
current sensor

Digital pressure sensor:
Instead of the analog pressure sensor MPX4100 you can now connect a combined pressure and temperature sensor MS5534A.
The connectors which are normaly used by the additional LTC2400 and the connector for the analog variometer signal are used then.
The benefit of this sensor is the larger range (300...1100mbar) and the calibration.
Attention: To use this sensor the reference voltage must adjust to 3.3 ... 3.6V (R1, R2).
Besides the sensor must be registered to the logger (use the "Loggerleserprogram" for this reason).


Manchester-2 to RS232 Decoder
This decoder is necessary if the bi-phase-code (Manchester-2-code) is used by the telemetry. This feature is configurable by the "Logerleserprogram".
The decoder is installed after the telemetry receiver and transform the Man-2-code to the normally used RS232-code for the PC or Palm.
The adjustable resistor adjust the threshold for the used data.The led show if the treshold is exeeded.
If RSSI is not available on the receiver then pin6 of the PIC12F629 must be connected to pin1.

Man2 to RS232 decoder Layout for Telemetry-Decoder

Following the software for the PIC12F629(675) for 4800baud:

The software is in the development phase and can measure only the following signals at the moment. The current software can be downloaded here:
  1. Software version V2.9 for the PIC-controller (inclusive bootloader): (for 32k /64k and 128kByte EEPROM)
    Remark: Install this version always first. Following versions will be loadable then via the internal bootloader of this version. 
  2. Betaversion V2.9h for the PIC-controller: (for 32k /64k and 128kByte EEPROM)
  3. Software for the PalmPilot: ( for V2.9g and higher versions, limited to 32k data)
  4. Brief description for the old Palm program (english): log_e.pdf
  5. Telemertry software for the PC: (Coefficients can be changed by 'SkyPlot')
  6. An Exel example sheet:
  7. The Windows software for the transmission of the dates to a computer as well as the program for showing of the GPS-data please download by :
  8.   (LoggerLeser: )
     (SkyPlot: )

Perhaps you can buy a finished datalogger in a lightly changed layout by Walter Windhagauer.

Questions, suggestions on the layout on: Jonas Romblad
Questions, suggestions on the design & software on: Dietrich Meissner

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