DS18X20 with AVR

Demo application to read DS1820, DS18S20 and DS18B20 temperature-sensors with an Atmel AVR controller. 1Wire-Bus with several devices on the wire supported, parasite power-supply supported without external FET ("strong-pullup" sourced from AVR-Portpin). The source-code is for avr-gcc/avr-libc. The 1-Wire- and DS18x20- routines may be used as "library" for own developments. 1-Wire-Bus I/O-Pin can be changed during runtime.

Credits: Peter Dannegger (some DS18x20- and most of the 1wire-code), Peter Fleury (uart-library), Colin O'Flynn (CRC-code)

P. Fleury's uart-library and P. Danneggers 1-Wire code have been slightly extended. There is not too much left from P. Dannegger's DS18x20-code but it has been the base for the presented "project". Used C. O'Flynns CRC8-Code only.

Changelog

  • 20. Sept. 2004 - Version 0.5
  • 30. Sept. 2004 - Version 0.6.1
  • 03. Oct. 2004 - Version 0.6.3, Run-time-config of 1-wire-bus, improved timeing
  • 24. Nov. 2004 - Version 0.6.4, Extended measurements for DS18(S)20 contributed by Carsten Foss (CFO)
  • 02. Feb. 2005 - Version 0.6.5, added function to read single sensor on OW-Bus (no rom-search needed), added demo using this function
  • 10. Mar. 2005 - Version 0.7, added functions to access the internal DS18x20 EEPROM
  • 01. Oct. 2009 - Version 0.8, Minor update (addtional delay ow_bit_io, using avrlibc delay, AVRStudio workspace)
  • 25. June 2010 - Version 0.9, Major modifications, see comments in source. Thanks to Karol Zdunski and Sascha Schade from suggestions and patches.
  • 17. July 2010 - Version 0.9.1, Improved recovery-time handling when parasite power is used. Thanks to Jürgen Liegner for the report and suggestions.
  • 9. Feb. 2011 - Version 0.9.2, added fix in format-function. Thanks to Marian Kulesza.

Hardware

  • Atmel AVR-Controller (ATmega16 and ATmega32 @ 1MHz, 2MHz, 4MHz, 8MHz internal R/C and 1,8432 MHz, 3.6864MHz ext. XTAL used for testing)
  • DS18X20 temperature-sensors (3 DS18B20 used during development)
  • 4,7 kOhm pull-up resistor for 1-Wire data-line
  • UART-connection to PC

Demo-Output

Version 0.6.x with two DS18B20

DS18X20 1-Wire-Reader Demo
--------------------------
Scanning Bus for DS18X20
2 DS18X20 Sensors available:
# in Bus :1 : FC:28 (18B)SN: 67 C6 6B 00 00 00 CRC:E2  CRC O.K. 
# in Bus :2 : FC:28 (18B)SN: 44 D7 6B 00 00 00 CRC:BC  CRC O.K. 
Sensor# 1 is a DS18B20 which is parasite powered
Sensor# 2 is a DS18B20 which is externally powered

Convert_T and Read for every Sensor (reverse order)
Sensor# 2 = +20.9375°C [+20.9°C]
Sensor# 1 = +20.8750°C [+20.9°C]

Convert_T for all Sensors and Read for single Sensor
Sensor# 1 = +20.8750°C [+20.9°C]
Sensor# 2 = +20.9375°C [+20.9°C]

Verbose output
FC:28 (18B)SN: 67 C6 6B 00 00 00 CRC:E2  CRC O.K. 
SP:4E 01 4B 46 7F FF 02 10 CRC:D9  CRC O.K. 
 T_raw=014E B20/12 +20.8750°C
FC:28 (18B)SN: 44 D7 6B 00 00 00 CRC:BC  CRC O.K. 
SP:4F 01 4B 46 7F FF 01 10 CRC:CF  CRC O.K. 
 T_raw=014F B20/12 +20.9375°C

Version 0.7 with one DS18B20

DS18X20 1-Wire-Reader Demo by Martin Thomas
-------------------------------------------
Scanning Bus for DS18X20
1 DS18X20 Sensor(s) available:
# in Bus :1 : FC:28 (18B)SN: 44 D7 6B 00 00 00 CRC:BC  CRC O.K. 
Sensor# 1 is a DS18B20 which is externally powered

DS18x20 EEPROM support test for first sensor
TH/TL from EEPROM sensor 1 : 140 / 141
TH+1 and TL+1 written to scratchpad
scratchpad copied to DS18x20 EEPROM
DS18x20 EEPROM copied back to scratchpad
TH and TL verified
TH/TL from EEPROM sensor 1 now : 141 / 142

There is only one sensor -> Demo of "read_meas_single":
+21.8125°C [+21.8°C]

Convert_T and Read Sensor by Sensor (reverse order)
Sensor# 1 = +21.8125°C [+21.8°C]

Convert_T for all Sensors and Read Sensor by Sensor
Sensor# 1 = +21.8125°C [+21.8°C]

Verbose output
FC:28 (18B)SN: 44 D7 6B 00 00 00 CRC:BC  CRC O.K. 
SP:5D 01 8D 8E 7F FF 03 10 CRC:BD  CRC O.K. 
 T_raw=015D B20/12 +21.8125°C

Version 0.9

DS18X20 1-Wire-Reader Demo by Martin Thomas
-------------------------------------------
Scanning Bus for DS18X20
1 DS18X20 Sensor(s) available:
# in Bus :1 : FC:28 (18B)SN: F9 E1 6B 00 00 00 CRC:E9  CRC O.K. 
Sensor# 1 is a DS18B20 which is parasite powered

DS18x20 EEPROM support test for fist sensor
TH/TL from EEPROM sensor 1 : 155 / 150
TH+1 and TL+1 written to scratchpad
scratchpad copied to DS18x20 EEPROM
DS18x20 EEPROM copied back to scratchpad
TH and TL verified
TH/TL from EEPROM sensor 1 now : 156 / 151

There is only one sensor -> Demo of "DS18X20_read_decicelsius_single":
232 deci°C, +23.2 °C

Convert_T and Read Sensor by Sensor (reverse order)
Sensor# 1 = 232 deci°C, +23.2 °C

Convert_T for all Sensors and Read Sensor by Sensor
Sensor# 1 = 232 deci°C, +23.2 °C
Sensor# 1 = 231875 °Ce-4, +23.1875 °C

Verbose output
FC:28 (18B)SN: F9 E1 6B 00 00 00 CRC:E9  CRC O.K. 
SP:74 01 9C 97 7F FF 0C 10 CRC:87  CRC O.K. 
 T_raw=0174 B20/12 +23.2500°C conv: 233 deci°C  fmt: +23.3 °C 





DS18X20 1-Wire-Reader Demo by Martin Thomas
-------------------------------------------
Scanning Bus for DS18X20
2 DS18X20 Sensor(s) available:
# in Bus :1 : FC:28 (18B)SN: F9 E1 6B 00 00 00 CRC:E9  CRC O.K. 
# in Bus :2 : FC:10 (18S)SN: 7E 26 88 00 08 00 CRC:A7  CRC O.K. 
Sensor# 1 is a DS18B20 which is parasite powered
Sensor# 2 is a DS18S20/DS1820 which is parasite powered

DS18x20 EEPROM support test for first sensor
TH/TL in scratchpad of sensor 1 now : 41 / 41
TH+1 and TL+1 written to scratchpad
TH/TL in scratchpad of sensor 1 now : 42 / 42
scratchpad copied to DS18x20 EEPROM
TH and TL in scratchpad set to 0
TH/TL in scratchpad of sensor 1 now : 0 / 0
DS18x20 EEPROM copied back to scratchpad
TH and TL verified
TH/TL in scratchpad of sensor 1 now : 42 / 42

Convert_T and Read Sensor by Sensor (reverse order)
Sensor# 2 = 244 deci°C, +24.4 °C
Sensor# 1 = 243 deci°C, +24.3 °C

Convert_T for all Sensors and Read Sensor by Sensor
Sensor# 1 = 243 deci°C, +24.3 °C
Sensor# 2 = 244 deci°C, +24.4 °C
Sensor# 1 = 243125 °Ce-4, +24.3125 °C
Sensor# 2 = 244375 °Ce-4, +24.4375 °C

Verbose output
FC:28 (18B)SN: F9 E1 6B 00 00 00 CRC:E9  CRC O.K. 
SP:85 01 2A 2A 7F FF 0B 10 CRC:9B  CRC O.K. 
 T_raw=0185 B20/12 +24.3125°C conv: 243 deci°C  fmt: +24.3 °C 
FC:10 (18S)SN: 7E 26 88 00 08 00 CRC:A7  CRC O.K. 
SP:31 00 67 62 FF FF 05 10 CRC:30  CRC O.K. 
 T_raw=0031 S20/09 +24.4375°C conv: 244 deci°C  fmt: +24.4 °C 



Test with AVR internal pull-up resistor instead of external:

DS18X20 1-Wire-Reader Demo by Martin Thomas
-------------------------------------------
Scanning Bus for DS18X20
2 DS18X20 Sensor(s) available:
# in Bus :1 : FC:28 (18B)SN: F9 E1 6B 00 00 00 CRC:E9  CRC O.K. 
# in Bus :2 : FC:10 (18S)SN: 7E 26 88 00 08 00 CRC:A7  CRC O.K. 
Sensor# 1 is a DS18B20 which is parasite powered
Sensor# 2 is a DS18S20/DS1820 which is parasite powered

DS18x20 EEPROM support test for first sensor
TH/TL in scratchpad of sensor 1 now : 50 / 50
TH+1 and TL+1 written to scratchpad
TH/TL in scratchpad of sensor 1 now : 51 / 51
scratchpad copied to DS18x20 EEPROM
TH and TL in scratchpad set to 0
TH/TL in scratchpad of sensor 1 now : 0 / 0
DS18x20 EEPROM copied back to scratchpad
TH and TL verified
TH/TL in scratchpad of sensor 1 now : 51 / 51

Convert_T and Read Sensor by Sensor (reverse order)
Sensor# 2 = 247 deci°C, +24.7 °C
Sensor# 1 = 242 deci°C, +24.2 °C

Convert_T for all Sensors and Read Sensor by Sensor
Sensor# 1 = 242 deci°C, +24.2 °C
Sensor# 2 = 248 deci°C, +24.8 °C
Sensor# 1 = 241875 °Ce-4, +24.1875 °C
Sensor# 2 = 247500 °Ce-4, +24.7500 °C

Verbose output
FC:28 (18B)SN: F9 E1 6B 00 00 00 CRC:E9  CRC O.K. 
SP:83 01 33 33 7F FF 0D 10 CRC:E0  CRC O.K. 
 T_raw=0183 B20/12 +24.1875°C conv: 242 deci°C  fmt: +24.2 °C 
FC:10 (18S)SN: 7E 26 88 00 08 00 CRC:A7  CRC O.K. 
SP:32 00 6A 65 FF FF 10 10 CRC:FD  CRC O.K. 
 T_raw=0032 S20/09 +24.7500°C conv: 248 deci°C  fmt: +24.8 °C

Software/Source-Code

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Martin Thomas



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