<Solved> Getting -0.000000 readings

[acekrystal]

Hello all,

I'm having a problem that some of my data send in the payload turns out as -0.000000 on the piGateway side.

My setup:
I'm using a Arduino -> RFM69 --> RFM69 -> piGateway structure.
I'm using a SHT31-D to read Humidity and Temperature.

Arduino code for SHT31-D:
// SHT31-D Temp/Hum. Sensor ==========================
#include <Arduino.h>
#include <Wire.h>
#include "Adafruit_SHT31.h"
Adafruit_SHT31 sht31 = Adafruit_SHT31();
    double h = 0;
    double t = 0;
// === end SHT31-D Temp/Hum. Sensor ======================

...

  sht31.begin(0x44);
     h = sht31.readHumidity(); // read Humidity
     t = sht31.readTemperature(); // read Temperature
//      t = round(t*10)/10.0; // Optional round at 1 decimal

   DEBUG1("Humidity=");
   DEBUG1(h);
   DEBUG1("   Temp=");
   DEBUGLN1(t);
//    DEBUGLN1("°C");
   temperature_time = millis();

   //send data
   theData.deviceID = 6;
   theData.var1_usl = millis();
   theData.var2_float = t;
   theData.var3_float = h;
   frameSent++;
   if (radio.sendWithRetry(GATEWAYID, (const void*)(&theData), sizeof(theData))) {
     ackReceived++;
     DEBUGLN1(" ACK received");
   } else {
     ackMissed++;
   }
   delay(1000);

output on Arduino Serial:
Humidity=57.61   Temp=24.95
ACK received
Humidity=57.57   Temp=24.92
ACK received
Humidity=57.56   Temp=24.95
ACK received

output on piGateway:
Pinging node 13 - ACK - nothing![13] to [1] Received Node ID = 13 Device ID = 6 Time = 6619768  RSSI = -63 var2 = 24.922562 var3 = 57.489891
[13] to [1] Received Node ID = 13 Device ID = 6 Time = 6621302  RSSI = -66 var2 = 24.922562 var3 = 57.456322
[13] to [1] Received Node ID = 13 Device ID = 6 Time = 6622832  RSSI = -66 var2 = 24.938583 var3 = -0.000000
Pinging node 13 - ACK - nothing![13] to [1] Received Node ID = 13 Device ID = 6 Time = 6624368  RSSI = -67 var2 = 24.922562 var3 = 57.502098
[13] to [1] Received Node ID = 13 Device ID = 6 Time = 6625902  RSSI = -67 var2 = 24.938583 var3 = -0.000000

Somehow it reads a lot of data as -0.000000. This only happens with var3, it aso happens when i swap temperature and humidity, again with var3.
It does not happen when I enable the round numbers:
//      t = round(t*10)/10.0; // Optional round at 1 decimal
I get the idea that the payload might be getting to big to propperly read some var3 value's.


My 2 questions:
1. Does someone know why this happens and how to solve it?
2. Why is my output on the Arduino serial numbers with 2 decimal(24.95), while after 433Mhz transfer it gets 6 decimals (24.948583), that also seem to have a valid value? Shouldn't DEBUGLN1(t); also show 6 decimals on Arduino Serial if SHT31D returned this? It feels like someone adds more decimals.

[acekrystal]

Problem solved!

Turns out it was the SPI_CLK pin not getting pulled down enough.
I added a 2.2K resistor between the SPI_CLK (pin 23 on OdroidC1+) and ground. (software pulldown did not seem to work)

Will run a test this night for stability

Details:
I discovered this because I had a other problem to fix: I coudn't let it run without my oscilloscoop attached...
I know this was related to the NSS pin, but I did not know yet the SPI_CLK pin was also giving troubles. I found this out after pulling the NSS down from within a gateway script, and having loads more -0.00000 value's when I started to disconnect the oscilloscoop from the ground pin. And the whole SPI connection broke after also disconnecting the oscilloscoop from the SPI CLK pin. Setting a pulldown for this pin in the gateway script seemed to not help, what pushed me in a wronge direction for a moment. later I tryed the hard way with a 2.2K resistor pullig to ground, and now it works without -0.0000 value's.

[acekrystal]

I still havent solved question 2 though...
Why direct printing value's on the arduino gives a number with 2 decimals. But after wireless transfer it has 6 decimals on the odroid side, and not even "0" decimals, but an actual value.

Someone any idea's?