raspberrypi_ads1115_thermocouple

Shellscript for the type-K thermocouple with ADS1115 on RaspberryPi.

setting

item	description
I2C_BUS=1	I2C bus number
ADS_ADDR="0x48"	ADS1115 I2C address
ADS_CONF_H_THERMO="0x8f"	settings of ADS1115 AD convert for typeK thermocouple
ADS_CONF_L_THERMO="0x03"	settings of ADS1115 AD convert for typeK thermocouple
ADS_CONF_H_LM61="0xe5"	settings of ADS1115 AD convert for LM61CIZ
ADS_CONF_L_LM61="0x03"	settings of ADS1115 AD convert for LM61CIZ
LSB_THERMO=7.8125	LSB voltage for typeK thermocouple
LSB_LM61=62.5	LSB voltage for LM61CIZ

usage

just execute. no need args.

[pi@raspberrypi]% ./ads1115.sh
Thermocouple_raw_HEX : 0008
LM61CIZ_raw_HEX      : 2FC4
Thermocouple_raw     : 8
LM61CIZ_raw          : 12228
Thermocouple_uV      : 62.5000 uV
LM61_uV              : 764250.0 uV
Thermocouple_degC    : 1.535626535626 degC
LM61_degC            : 16.425000000000 degC
RESULT : 17.960626535626 degC

software requirements

• zsh
• i2cset
• i2cget
• sed
• bc
• sleep, tr

hardware list

• RaspberryPi, OrangePi, C.H.I.P. and i2cget/i2cset working environment.
• ADS1115
• typeK tyermocouple
• LM61CIZ

hardware connection

                  ADS1115                      RaspberryPi
              +------------+                    +-------+
              |        ALART--Open              |       |
              |            |                    |       |
Thermo(Cr)----ANI0       SCL--------------------SCL     |
              |            |                    |       |
Thermo(Al)--*-ANI1       SDA--------------------SDA     |
            | |            |                    |       |
   LM61CIZ--+-ANI2       VDD-----*--------------3.3V    |
    | |     | |            |     |              |       |
    | | NC--+-ANI3      ADDR-*---+-----------*--GND     |
    | |     | |            | |   |           |  |       |
    | |     | |          GND-+   |           |  |       |
    | |     | |            |     |           |  |       |
    | |     | +------------+     |           |  +-------+
    | |     |                    |           |
    | +-----+--------------------+-----------*
    |       |                    |           |
    +-------+--------------------*           |
            |                    |           |
            *---[R 2k Ohm]-------*           |
            |                                |
            *---[R 2k Ohm]-------------------*
            |                                |
            +---[C 0.1 uF]-------------------*

+ corner/cross-over
* connect