For his USC Rocket Propulsion Lab, Chris Fenton designed this project using a Picaxe 18X microcontroller which accepts a GPS NMEA data stream, pulls out the altitude and logs it to a 24LC512 external EEPROM. Upon recovery the data is then read from the EEPROM. Source code for the Picaxe and hand drawn schematic for this hasty project are provided.
An analysis of the circuit and chip datasheet reveals that the 3 pin female header on the schematic is for serial IO, and that the GPS can interface via DB9 connector with a rocket mounted transmitter to send real-time GPS data in addition to EEPROM logging. NOTE: It appears that fifth line of code which reads, “if input0=0 then readback” should read “if input1=1 then readback”. This is the input which triggers the data readout from the EEPROM.
Via PyroElectro.