I am working on a project with my son, monitoring the temperature and humidity in his chameleon’s cage. I had dreams of father-of-the-year with this one . My son is helping with the code and with the 3D case. But alas no, no red carpet for me this year…
I cannot get this little sensor to accurately read temperature, though it is very accurate!
I need some help with this BME280 breakout board from DIY Mall. I’m certain that the problem is electronic. That is, the sensor reads the temperature very well on a cold startup, but then the temperature starts to creep up. I am only reading it once a minute, so I don’t think I’m sampling too often. I’ve tested with and without pull-up resistors (that’s for you @bko). The sensor communicates either way quite nicely but there seems to be some heat on the tiny board.
My thought is that the sensor (obverse side, there are multiple photos in the link) may be too close to the power regulator (reverse side along wth the I<sup2C chip and a few resistors) and that the heat from the regulator may be flooding the little board. In a 72°F room, the measured temperature rises from 72°F to about 77°F. I am powering the board with 3.3V from a Photon.
The problem worsens when I added an OLED display. I am running the two devices from hardware I2C digital pins zero and one. Updating the display every 2500ms, the measured temperature will then further rise to about 85°F. I’m thinking that the additional communication to the OLED display may be exasperating the problem.
I tried to dynamically power the sensor board (i.e powering with a transistor with a digital pin on the gate) but could not get that to work (read consistently).
So I am looking for some advice in order to ameliorate the heat-rise issue.
Any recommendation on what to do in code?
Is there anything I can do to the board (perhaps some magic Heat-Be-Gone spray ;)) to minimize the effects of power and/or communications causing this heat rise?
Thanks for any suggestions, heck thanks for reading this far down!
** fyi DIY Mall did agree to replace the sensors (one year warrantee) but I’m afraid the replacements will have the same issue. I guess there may also be the problem of the voltage regulator excessively making heat.