NTC temperature sensor going to A:D input. Topology is: (Vref or 3.3V) -> Series_resistor -> A:D_input -> NTC -> GND. Easy modification of NTC parameters w/o recompile of library
ntc.cpp@0:c0bdc272d5da, 2017-04-07 (annotated)
- Committer:
- loopsva
- Date:
- Fri Apr 07 00:30:39 2017 +0000
- Revision:
- 0:c0bdc272d5da
- Child:
- 2:c843c06cc651
Initial release of NTC temperature sensor going to A:D input
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
loopsva | 0:c0bdc272d5da | 1 | /* |
loopsva | 0:c0bdc272d5da | 2 | * mbed library program |
loopsva | 0:c0bdc272d5da | 3 | */ |
loopsva | 0:c0bdc272d5da | 4 | |
loopsva | 0:c0bdc272d5da | 5 | #include "mbed.h" |
loopsva | 0:c0bdc272d5da | 6 | #include "ntc.h" |
loopsva | 0:c0bdc272d5da | 7 | |
loopsva | 0:c0bdc272d5da | 8 | NTC::NTC(PinName p_ana, const NTC_TypeDef *ntc_parameter) : |
loopsva | 0:c0bdc272d5da | 9 | _ana(p_ana) |
loopsva | 0:c0bdc272d5da | 10 | { |
loopsva | 0:c0bdc272d5da | 11 | ntc_set_data = *ntc_parameter; |
loopsva | 0:c0bdc272d5da | 12 | rawdata = NULL; |
loopsva | 0:c0bdc272d5da | 13 | } |
loopsva | 0:c0bdc272d5da | 14 | |
loopsva | 0:c0bdc272d5da | 15 | NTC::NTC(PinName p_ana) : |
loopsva | 0:c0bdc272d5da | 16 | _ana(p_ana) |
loopsva | 0:c0bdc272d5da | 17 | { |
loopsva | 0:c0bdc272d5da | 18 | ntc_set_data = ntc_std_paramtr; |
loopsva | 0:c0bdc272d5da | 19 | rawdata = NULL; |
loopsva | 0:c0bdc272d5da | 20 | } |
loopsva | 0:c0bdc272d5da | 21 | |
loopsva | 0:c0bdc272d5da | 22 | uint16_t NTC::read_ad_reg() { |
loopsva | 0:c0bdc272d5da | 23 | rawdata = _ana.read_u16(); |
loopsva | 0:c0bdc272d5da | 24 | return rawdata; |
loopsva | 0:c0bdc272d5da | 25 | //return 19918; //85.00c * ntc=10k, b=3434, rser=3320 |
loopsva | 0:c0bdc272d5da | 26 | } |
loopsva | 0:c0bdc272d5da | 27 | |
loopsva | 0:c0bdc272d5da | 28 | int NTC::get_ntc_res() { |
loopsva | 0:c0bdc272d5da | 29 | return ntc_set_data.ntc_res; |
loopsva | 0:c0bdc272d5da | 30 | } |
loopsva | 0:c0bdc272d5da | 31 | |
loopsva | 0:c0bdc272d5da | 32 | int NTC::get_ntc_beta_2550() { |
loopsva | 0:c0bdc272d5da | 33 | return ntc_set_data.ntc_beta_2550; |
loopsva | 0:c0bdc272d5da | 34 | } |
loopsva | 0:c0bdc272d5da | 35 | |
loopsva | 0:c0bdc272d5da | 36 | int NTC::get_ntc_beta_2580() { |
loopsva | 0:c0bdc272d5da | 37 | return ntc_set_data.ntc_beta_2580; |
loopsva | 0:c0bdc272d5da | 38 | } |
loopsva | 0:c0bdc272d5da | 39 | |
loopsva | 0:c0bdc272d5da | 40 | int NTC::get_ntc_beta_2585() { |
loopsva | 0:c0bdc272d5da | 41 | return ntc_set_data.ntc_beta_2585; |
loopsva | 0:c0bdc272d5da | 42 | } |
loopsva | 0:c0bdc272d5da | 43 | |
loopsva | 0:c0bdc272d5da | 44 | int NTC::get_ntc_beta_25100() { |
loopsva | 0:c0bdc272d5da | 45 | return ntc_set_data.ntc_beta_25100; |
loopsva | 0:c0bdc272d5da | 46 | } |
loopsva | 0:c0bdc272d5da | 47 | |
loopsva | 0:c0bdc272d5da | 48 | int NTC::get_series_res() { |
loopsva | 0:c0bdc272d5da | 49 | return ntc_set_data.sres_res; |
loopsva | 0:c0bdc272d5da | 50 | } |
loopsva | 0:c0bdc272d5da | 51 | |
loopsva | 0:c0bdc272d5da | 52 | float NTC::get_ntc_res_viaAD(uint16_t din) { |
loopsva | 0:c0bdc272d5da | 53 | uint16_t ad = rawdata; |
loopsva | 0:c0bdc272d5da | 54 | if(din == 0) { |
loopsva | 0:c0bdc272d5da | 55 | ad = NTC::read_ad_reg(); |
loopsva | 0:c0bdc272d5da | 56 | } |
loopsva | 0:c0bdc272d5da | 57 | float adv = ntc_set_data.vref / ntc_set_data.ad_resolution * (float)ad; |
loopsva | 0:c0bdc272d5da | 58 | return (ntc_set_data.vref / ((ntc_set_data.vref - adv) / ntc_set_data.sres_res) - ntc_set_data.sres_res); |
loopsva | 0:c0bdc272d5da | 59 | } |
loopsva | 0:c0bdc272d5da | 60 | |
loopsva | 0:c0bdc272d5da | 61 | float NTC::get_ntc_temp(int curve, uint16_t din) { |
loopsva | 0:c0bdc272d5da | 62 | int beta = 0; |
loopsva | 0:c0bdc272d5da | 63 | switch (curve) { |
loopsva | 0:c0bdc272d5da | 64 | case B25_50: |
loopsva | 0:c0bdc272d5da | 65 | beta = ntc_set_data.ntc_beta_2550; |
loopsva | 0:c0bdc272d5da | 66 | break; |
loopsva | 0:c0bdc272d5da | 67 | case B25_80: |
loopsva | 0:c0bdc272d5da | 68 | beta = ntc_set_data.ntc_beta_2580; |
loopsva | 0:c0bdc272d5da | 69 | break; |
loopsva | 0:c0bdc272d5da | 70 | case B25_85: |
loopsva | 0:c0bdc272d5da | 71 | beta = ntc_set_data.ntc_beta_2585; |
loopsva | 0:c0bdc272d5da | 72 | break; |
loopsva | 0:c0bdc272d5da | 73 | case B25_100: |
loopsva | 0:c0bdc272d5da | 74 | beta = ntc_set_data.ntc_beta_25100; |
loopsva | 0:c0bdc272d5da | 75 | break; |
loopsva | 0:c0bdc272d5da | 76 | default: |
loopsva | 0:c0bdc272d5da | 77 | beta = ntc_set_data.ntc_beta_2550; |
loopsva | 0:c0bdc272d5da | 78 | break; |
loopsva | 0:c0bdc272d5da | 79 | } |
loopsva | 0:c0bdc272d5da | 80 | float ntc_res = 0.0f; |
loopsva | 0:c0bdc272d5da | 81 | if(din == 0) { |
loopsva | 0:c0bdc272d5da | 82 | ntc_res = NTC::get_ntc_res_viaAD(); |
loopsva | 0:c0bdc272d5da | 83 | } else { |
loopsva | 0:c0bdc272d5da | 84 | ntc_res = NTC::get_ntc_res_viaAD(din); |
loopsva | 0:c0bdc272d5da | 85 | } |
loopsva | 0:c0bdc272d5da | 86 | return (beta / (log(ntc_res / (ntc_set_data.ntc_res * exp(-beta / 298.0f)))) - 273.0f); |
loopsva | 0:c0bdc272d5da | 87 | } |
loopsva | 0:c0bdc272d5da | 88 |