add circuit diagram for ADC_CT

Author: barbudor

docs/ADC.md

@@ -54,7 +54,7 @@ Example: ADC as `Light (3)`
 
 Command|Parameters
 :---|:---
-AdcParam<x\><a class="cmnd" id="adcparam"></a>|[ADC](ADC) analog input tuning parameters. On ESP32 x is channel `1..8`, and the input max is 4095 instead of 1023 as used below.<br>`<sensor>, <param1>, <param2>, <param3>,  <param4>`<BR>`<sensor>` values:<br>&emsp; `2` = Temperature [Steinhart-Hart thermistor equation](https://en.wikipedia.org/wiki/Steinhart%E2%80%93Hart_equation) parameters:</li><ul>`<param1>` = NTC Voltage bridge resistor in Ohms *(default = `32000`)*<br>`<param2>` = NTC Resistance in Ohms *(default = `10000`)*<BR>`<param3>` = NTC Beta Coefficient *(default = `3350`)*</li></ul><br>&emsp; `3` = Light [Lux equation](https://www.allaboutcircuits.com/projects/design-a-luxmeter-using-a-light-dependent-resistor/) parameters:</li><ul>`<param1>` = LDR Voltage bridge resistor in Ohms *(default = `10000`)*<BR>`<param2>` = LDR Lux Scalar *(default = `12518931`)*<BR>`<param3>` = LDR Lux Exponent *(default = `-1.4050`)*</li></ul><br>&emsp; `6` = ADC linear range remapping parameters:</li><ul>`<param1>` = input range low value `adcLow` *(default = `0`)*<BR>`<param2>` = input range high value `adcHigh` *(default = `1023`)*<BR>`<param3>` = output range low value `rangeLow` *(default = `0`)*<BR>`<param4>` = output range high value `rangeHigh` *(default = `100`)*<BR>The range remapping perform the following calculation on the ADC value *[0..1023]*:<BR>`Range = ((adcHigh - ADC) / (adcHigh - adcLow)) * (rangeLow - rangeHigh) + rangeHigh`<br>*The calculation is performed in double resolution floating point, but the output is a signed integer. All 4 input parameters are unsigned 16 bit integers.*<BR>Example to convert the ADC value on a D1-mini into millivolts (using the default resistor bridge of 220k/100k):<BR>`AdcParam 6, 0, 1023, 0, 3200`</li></ul><br>&emsp; `7` = CT POWER parameter adjustments:</li><ul>`<param1>` = ANALOG_CT_FLAGS (default 0 for a non-invasive current sensor). When value is `>0` it sets the `adcLow` value as base for the measurement via OpAmp differential amplifier.<BR>`<param2>` = ANALOG_CT_MULTIPLIER ( 2146 = Default settings for a (AC) 20A/1V Current Transformer.) multiplier\*100000 to convert raw ADC peak to peak range 0..1023 to RMS current in Amps. Value of 100000 corresponds to 1<BR>`<param3>` = ANALOG_CT_VOLTAGE (default 2300) to convert current in Amps to apparent power in Watts using voltage in Volts/1000. Use value 0.220 for AC220V or 0.012 for 12VDC.<BR>`<param4>` minimum current threshold (AC only, optional, default 0). Current measured below this value will be forced to 0.0. Used to void measurment noise when load is null.<BR>Exemple for DC: `AdcParam 7,406,3282,0.012`<BR>Exemple for AC: `AdcParam 7,0,2146,0.230,0.060`</li></ul><BR>&emsp; `9` = ANALOG_PH parameter adjustments:</li><ul>`<param1>` = ANALOG_PH_CALSOLUTION_LOW_PH (default 4.0).<BR>`<param2>` = ANALOG_PH_CALSOLUTION_LOW_ANALOG_VALUE ( default 282 )<BR>`<param3>` = ANALOG_PH_CALSOLUTION_HIGH_PH (default 9.18).<BR>`<param4>` = ANALOG_PH_CALSOLUTION_HIGH_ANALOG_VALUE (default 435).<BR><BR>To calibrate the probe, two reference solutions with known pH are required. Calibration procedure: <ol><li>Put probe in solution with lower pH value. pH value of the solution is ANALOG_PH_CALSOLUTION_LOW_PH.</li><li>Wait until analog value / RAW value stabilizes (~3 minutes)</li><li>The analog reading is ANALOG_PH_CALSOLUTION_LOW_ANALOG_VALUE</li><li>Clean probe and put in solution with higher pH value. pH value of the solution is ANALOG_PH_CALSOLUTION_HIGH_PH.</li><li>Wait until analog value / RAW value stabilizes (~3 minutes)</li><li>The analog reading is ANALOG_PH_CALSOLUTION_HIGH_ANALOG_VALUE</li></ol>Analog readings can be read by either changing the analog port configuration to "Analog Input" while calibrating, or by enabling debug logs in the console and having a look at the `RAW Value`reading instead.</li></ul><BR>&emsp; `10` = MQ-X sensors parameter adjustments:</li><ul>`<param1>` = ANALOG_MQ_TYPE (default 2) It used to specify sensor type. At the moment exists: 2, 3, 4, 5, 6, 7, 8, 9, 131, 135 (means MQ-02, MQ-03, MQ-04 ecc.).<BR>`<param2>` = ANALOG_MQ_A (default 574.25 a params for MQ-02) It is exponential regression a params<BR>`<param3>` = ANALOG_MQ_B (default -2.222 b params for MQ-02) It is exponential regression b params, generally negative<BR>`<param4>` = ANALOG_MQ_RatioMQCleanAir (default 15.0 RatioMQCleanAir params for MQ-02) NOT USED YET. It is threshold for good air in ppm for future alams arming<BR>Usage example for MQ-02, MQ-04, MQ-07 and MQ-131<BR> `AdcParam 10, 2.00, 574.25, -2.22, 9.83`<BR> `AdcParam 10, 4.00, 1012.70, -2.79, 4.40 `<BR> `AdcParam 10, 7.00, 99.04, -1.52, 27.50 `<BR> `AdcParam 10, 131.00, 23.94, -1.11, 15.00 `</li></ul><BR>
+AdcParam<x\><a class="cmnd" id="adcparam"></a>|[ADC](ADC) analog input tuning parameters. On ESP32 x is channel `1..8`, and the input max is 4095 instead of 1023 as used below.<br>`<sensor>, <param1>, <param2>, <param3>,  <param4>`<BR>`<sensor>` values:<br>&emsp; `2` = Temperature [Steinhart-Hart thermistor equation](https://en.wikipedia.org/wiki/Steinhart%E2%80%93Hart_equation) parameters:</li><ul>`<param1>` = NTC Voltage bridge resistor in Ohms *(default = `32000`)*<br>`<param2>` = NTC Resistance in Ohms *(default = `10000`)*<BR>`<param3>` = NTC Beta Coefficient *(default = `3350`)*</li></ul><br>&emsp; `3` = Light [Lux equation](https://www.allaboutcircuits.com/projects/design-a-luxmeter-using-a-light-dependent-resistor/) parameters:</li><ul>`<param1>` = LDR Voltage bridge resistor in Ohms *(default = `10000`)*<BR>`<param2>` = LDR Lux Scalar *(default = `12518931`)*<BR>`<param3>` = LDR Lux Exponent *(default = `-1.4050`)*</li></ul><br>&emsp; `6` = ADC linear range remapping parameters:</li><ul>`<param1>` = input range low value `adcLow` *(default = `0`)*<BR>`<param2>` = input range high value `adcHigh` *(default = `1023`)*<BR>`<param3>` = output range low value `rangeLow` *(default = `0`)*<BR>`<param4>` = output range high value `rangeHigh` *(default = `100`)*<BR>The range remapping perform the following calculation on the ADC value *[0..1023]*:<BR>`Range = ((adcHigh - ADC) / (adcHigh - adcLow)) * (rangeLow - rangeHigh) + rangeHigh`<br>*The calculation is performed in double resolution floating point, but the output is a signed integer. All 4 input parameters are unsigned 16 bit integers.*<BR>Example to convert the ADC value on a D1-mini into millivolts (using the default resistor bridge of 220k/100k):<BR>`AdcParam 6, 0, 1023, 0, 3200`</li></ul><br>&emsp; `7` = CT POWER parameter adjustments:</li><ul>`<param1>` = ANALOG_CT_FLAGS (default 0 for a non-invasive current sensor). When value is `>0` it sets the `adcLow` value as base for the measurement via OpAmp differential amplifier.<BR>`<param2>` = ANALOG_CT_MULTIPLIER ( 2146 = Default settings for a (AC) 20A/1V Current Transformer.) multiplier\*100000 to convert raw ADC peak to peak range 0..1023 to RMS current in Amps. Value of 100000 corresponds to 1<BR>`<param3>` = ANALOG_CT_VOLTAGE (default 2300) to convert current in Amps to apparent power in Watts using voltage in Volts/1000. Use value 0.220 for AC220V or 0.012 for 12VDC.<BR>`<param4>` minimum current threshold (AC only, optional, default 0). Current measured below this value will be forced to 0.0. Used to void measurment noise when load is null.<BR>Exemple for DC: `AdcParam 7,406,3282,0.012`<BR>Exemple for AC: `AdcParam 7,0,2146,0.230,0.060`<BR>See circuit diagram [below](#adc_ct-circuit)</li></ul><BR>&emsp; `9` = ANALOG_PH parameter adjustments:</li><ul>`<param1>` = ANALOG_PH_CALSOLUTION_LOW_PH (default 4.0).<BR>`<param2>` = ANALOG_PH_CALSOLUTION_LOW_ANALOG_VALUE ( default 282 )<BR>`<param3>` = ANALOG_PH_CALSOLUTION_HIGH_PH (default 9.18).<BR>`<param4>` = ANALOG_PH_CALSOLUTION_HIGH_ANALOG_VALUE (default 435).<BR><BR>To calibrate the probe, two reference solutions with known pH are required. Calibration procedure: <ol><li>Put probe in solution with lower pH value. pH value of the solution is ANALOG_PH_CALSOLUTION_LOW_PH.</li><li>Wait until analog value / RAW value stabilizes (~3 minutes)</li><li>The analog reading is ANALOG_PH_CALSOLUTION_LOW_ANALOG_VALUE</li><li>Clean probe and put in solution with higher pH value. pH value of the solution is ANALOG_PH_CALSOLUTION_HIGH_PH.</li><li>Wait until analog value / RAW value stabilizes (~3 minutes)</li><li>The analog reading is ANALOG_PH_CALSOLUTION_HIGH_ANALOG_VALUE</li></ol>Analog readings can be read by either changing the analog port configuration to "Analog Input" while calibrating, or by enabling debug logs in the console and having a look at the `RAW Value`reading instead.</li></ul><BR>&emsp; `10` = MQ-X sensors parameter adjustments:</li><ul>`<param1>` = ANALOG_MQ_TYPE (default 2) It used to specify sensor type. At the moment exists: 2, 3, 4, 5, 6, 7, 8, 9, 131, 135 (means MQ-02, MQ-03, MQ-04 ecc.).<BR>`<param2>` = ANALOG_MQ_A (default 574.25 a params for MQ-02) It is exponential regression a params<BR>`<param3>` = ANALOG_MQ_B (default -2.222 b params for MQ-02) It is exponential regression b params, generally negative<BR>`<param4>` = ANALOG_MQ_RatioMQCleanAir (default 15.0 RatioMQCleanAir params for MQ-02) NOT USED YET. It is threshold for good air in ppm for future alams arming<BR>Usage example for MQ-02, MQ-04, MQ-07 and MQ-131<BR> `AdcParam 10, 2.00, 574.25, -2.22, 9.83`<BR> `AdcParam 10, 4.00, 1012.70, -2.79, 4.40 `<BR> `AdcParam 10, 7.00, 99.04, -1.52, 27.50 `<BR> `AdcParam 10, 131.00, 23.94, -1.11, 15.00 `</li></ul><BR>
 
 ### Rule triggers
 Use these triggers in rules:    
@@ -66,6 +66,26 @@ Use these triggers in rules:
 
 Rule example: [using a potentiometer on analog pin](Rules#use-a-potentiometer).
 
+## ADC_CT circuit
+
+You should use a current transformer with voltage output such as a 20A/1V or 50/1V. Do not use a CT with current output.
+
+The below circuit shows how to connect the CT. The exact values for the capacitors or the resitors is not very critical 
+(values that are double or half will work the same but the 2 resitors should be the same value).
+
+In order to avoid noise, You should build the most compact as possible, use short wires.
+
+![ADC_CT circuit](_media/ADC_CT_circuit.png)
+
+!!! note
+     The section on the right represent the voltage divider that is present on the NodeMCU or mini-D1 to 
+     provide a [0.0 - 3.3V] input range (native range of ESP8266 ADC pin is 0.0-1.0V). If you are using 
+     a bare ESP8266 module without that divider, you need to add it.
+
+!!! note
+     ESP32 natively have a [0.0 - 3.3V] input range and doesn't need such divider on the right.
+
+
 ## ADC_VCC
 Instead of an input, ADC pin can be used to measure supply voltage of the ESP module (*this reading in not 100% accurate*). To enable ADC_VCC feature you need to [compile your own build](Compile-your-build):