Serial printing Is a blocking function and is a big chunk of time that must.be shared with the GPS sentence parsing. My answer was to print the support text and only update the changed data. I had a baro sensor an RH/temp sensor and tested two GPS Devices both with the same issues until I split the main data form or screen into drawing the static data (the labels) and when required data changed I updated that data as required. Since the RH data requires ~2.5 seconds between measurements I updated the barometer at twice the rate of the RH/Temp data and the display at the same time.
Time on the second, and the RH data once every 3 seconds. The BMP 085 was updated every 5 seconds.
This worked well with all but the Adafruit 1.8 display which requires 'clearing' or printing a blank field or box prior to printing new data I cleared the field first then wrote the data to the cleared area. The '7735 adafruit library only updates the new pixels it doesn't clear them first.
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