ads1x1x: added support for ADC chip

docs/Config_Reference.md

@@ -4824,6 +4824,50 @@ vssa_pin:
 #   noise. The default is 2 seconds.
 ```
 
+### [ads1x1x]
+
+ADS1013, ADS1014, ADS1015, ADS1113, ADS1114 and ADS1115 are I2C based Analog to
+Digital Converters that can be used for temperature sensors. They provide 4
+analog input pins either as single line or as differential input.
+
+Note: Use caution if using this sensor to control heaters. The heater min_temp
+and max_temp are only verified in the host and only if the host is running and
+operating normally. (ADC inputs directly connected to the micro-controller
+verify min_temp and max_temp within the micro-controller and do not require a
+working connection to the host.)
+
+```
+[ads1x1x my_ads1x1x]
+chip: ADS1115
+#pga: 4.096V
+#   Default value is 4.096V. The maximum voltage range used for the input. This
+#   scales all values read from the ADC. Options are: 6.144V, 4.096V, 2.048V,
+#   1.024V, 0.512V, 0.256V
+#adc_voltage: 3.3
+#   The suppy voltage for the device. This allows additional software scaling
+#   for all values read from the ADC.
+i2c_mcu: host
+i2c_bus: i2c.1
+#address_pin: GND
+#   Default value is GND.  There can be up to four addressed devices depending
+#   upon wiring of the device. Check the datasheet for details. The i2c_address
+#   can be specified directly instead of using the address_pin.
+```
+
+The chip provides pins that can be used on other sensors.
+
+```
+sensor_type: ...
+#   Can be any thermistor or adc_temperature.
+sensor_pin: my_ads1x1x:AIN0
+#   A combination of the name of the ads1x1x chip and the pin. Possible
+#   pin values are AIN0, AIN1, AIN2 and AIN3 for single ended lines and
+#   DIFF01, DIFF03, DIFF13 and DIFF23 for differential between their
+#   correspoding lines. For example
+#   DIFF03 measures the differential between line 0 and 3. Only specific
+#   combinations for the differentials are allowed.
+```
+
 ### [replicape]
 
 Replicape support - see the [beaglebone guide](Beaglebone.md) and the