My next step I wanted to try out some ambient measurements to add to the history of roasts once I get things logging. I’ve seen plenty of roast master setups having humidity and temperature readings around the area they work in and figured…. might be a good idea of something to try logging at the beginning of the roasts. One of the options was the SHT15 sensor. After about a day of poking around and reading data sheets I got it wired in and read a bunch of PIC16 and PIC18 and one PIC24 set of source code written for the SHT15. Upon looking through their code I can’t even begin to understand why most of that code even works because many times it does NOT conform to the requirements as stated in the data sheet. I’m pretty certain that most of that code got it to work “by accident” rather than by design.
As of now I’ve managed to get the SHT15 to report temperature readings reliably back to back in a loop for several dozen hits but could not get humidity to respond during that run. It responded appropriately when warmth was applied in the area of the sensor and then….. I rebooted the circuit after inserting a set of formulas to convert the reading to a real temperature number. I figured it was working and I didnt want to have to manually do the math. Upon starting it I found it immediately went back to 65535. I did an undo, recompile, and program and nada. Still 65535.
Wheeeeee
I’m pretty sure this is some sort of timing issue but it could be an issue with the pull up resistors too I suppose. I need to read more about the voltage I’m using vs the resistors on the bus and the length of wiring involved as well. I may be getting some sort of interference with all the gear on the desk right now and there were a few forum conversations talking about the length of wiring being somewhat sensitive for some people.