Dear David, Thanks a lot for your reply.
According to your suggestion I tried to implement the formula like below: _centiGrade = (float)-39.00 + (float)0.0098 * val; The compiler whines about loosing precession...can you please tell me if the way I used casting in the formula is trustworthy? Regards, Sean. ----- Original Message ----- From: David Guillen Sent: 06/13/13 12:20 PM To: Sean Dekker Subject: Re: [Tinyos-help] Real ADC values from SHT11 sensor on TelosB Hi Sean, If you check the sensor datasheet you can read in the first paragraph that STH11 has 14 bits resolution. That means it value can go to 2¹⁴ = 16384. You can convert the raw reading, independently of the power supply, using these formulas: TEMP Ta [ºC] = -39 + 0,0098 * READING_VALUE HUM a = READING_VALUE b = -0,0000028 * a * a + 0,0405 * a – 4 Hum [%] = (Ta [ºC] – 25) * (0,01 + 0,00008 * a) + b I attach the datasheet for further information. Regards, David G. On 11 June 2013 18:50, Sean Dekker < [email protected] > wrote:Hi all, Can someone please tell me what is the range of RAW data from the temparature sensor on TelosB? I was thinking it should be 0-4096 but I am getting values like 6553 or so...Am I doing something wrong? Also, for the conversion formula...is the conversion formula different when the TelosB is powered via USB compared when its powered by AA batteries? Regards, Sean. _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help -- David Guillén Jiménez
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