Boat project 2 - Barograph

cpedw

Senior Member
This project is a 5 day barometric pressure recorder. It uses a graphic LCD to display previous measurements. It also uses a version of the 18X internal timer described by Hippy to identify hour-long intervals. And there's a nifty device store each measurement in half a byte, to save on memory usage.
The LCD and pressure transducer make this quite an expensive project but it's useful for the weather-obsessed.

Derek.
ps Apologies for loading the program as a pdf; it's too big to load as .bas, sorry.
 

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cpedw

Senior Member
Barograph program

I just realised it's not at all easy to extract the program from the pdf so here it is in its original form but in two parts so it can fit the website.
Derek.
 

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cpedw

Senior Member
Picaxe has moved on in 7 years. I have modified the Barograph to run on an 18M2, which has simplified the program considerably and allowed an improvement in functionality. whereas before the display was limited to the range 968mbar to 1031 mbar, it can now go down to 850mbar and up to 1168mbar.

The display is still restricted to a range of 64mbar but if the latest reading will fall off the display, the whole preceding display is moved up or down by 10mbar to ensure the latest reading is on the display. Earlier readings might possibly be lost but that seems unlikely, since the old arrangement has only let me down a few times, during prolonged very settled weather when the pressure has gone above 1030mbar for several days.

The original circuit is unchanged so there's no need to get out the soldering iron.

I tried the syntax checker on a 14M2 version and it passed so I think it would work fine there but I haven't tried it in hardware.

Derek
 

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