DHT Sensor data filtering method for photon - some logic mistake?

Firmware
21

@Suriken, About that distance … I am experimenting with the DHT22 and with the BME280.
I bought both sensors for different purposes, and then had to reverse the roles over the distance issue.

I have tried the DHT22 on the breadboard at 10cm and at approximately 11m. It works just fine at 10cm if it is wired up properly. At 11m, it causes my photon to crash and flash a red SOS (same SOS as if I had wired it up incorrectly; I did that too in the beginning). In theory the DHT22 will work within a meter or 2.

@BulldogLowell & @peekay123 I also have tried the BME280 at close range, which I find is a very nice sensor. The BME280 can operate by SPI or I2C (at least the Adafruit breakout version which I have for prototyping), I still have to try it at 11m, but theory says that should fail. I have read posts that indicate I2C is good for up to about 7m, depending on capacitance in the system. My backup plan is to try adding the P82B715 chip which is an I2C capacitance buffer at each end of the I2C bus; theory says that should get a 50m range. Failing that, the expensive option is to use a Dallas 1-wire Battery Fuel Gauge chip for its built-in temperature sensor and hack the voltage monitor to measure an analog humidity sensor.

Hope that gives you some ideas that there are lots of experiments to find what works best!

22

Could you guys just use a second Photon + temp sensor and send the temp sensor data via a webhook and receive that webhook on the 2nd Photon?

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23

Thank you @cyclin_al. I gues I won’t have problems with none of them neither since I will be under 2 meters all the time. I have tested dht22 with a 1m wire and it works fine. If I have time today I will order a couple of bmp280 but I haven’t found a proper enclousure for this sensor, just the dev board from adafruit/chinese clones.

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@RWB, that is an option that will definitely work. For my particular situation, adding a bunch of Photons will be $30 CDN each plus running heavier cabling for power. Using a couple of P82B715s on custom circuit boards would only add $6 CDN to the cost of each sensor. I am avoiding the 1-wire solution if possible; that might actually be close to the same cost as adding Photons; in which case the Photon would also be easier to implement. I am assuming my WiFi range would be okay for those sensor locations.

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