Using Float on input

New user here checking things out. Everything is working good except trying to use a calibration factor on the analog input. I can’t find an example or figure out how to use “float” on an input. If there is a better way to incorporate a calibration factor please enlighten me.
Compile error is: exit status 1
‘voltage’ is not captured’
Thank You,

#include <ThingerESP8266.h>
#include <OneWire.h>
#include <DallasTemperature.h>

// Usual login stuff here::::

#define ONE_WIRE_BUS 2 
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

void setup() {


  thing.add_wifi(SSID, SSID_PASSWORD);

    pinMode(LED_BUILTIN, OUTPUT); 

    // digital pin control example (i.e. turning on/off a light, a relay, configuring a parameter, etc)
  thing["led"] << digitalPin(LED_BUILTIN);
  thing["led"] << invertedDigitalPin(LED_BUILTIN);

  thing["Temperature"] >> [](pson & out) {
  sensors.requestTemperaturesByIndex(0); // Send the command to get temperatures
  out = (int) sensors.getTempFByIndex(0);
  thing["RSSI"] >> outputValue (WiFi.RSSI());

  thing["AC"] >> outputValue(digitalRead(16));

  thing["door"] >> outputValue(digitalRead(5));

  int analogValue = analogRead(A0); // read the input on analog pin 0,   Battery volts
      float voltage;
      voltage = analogValue * .1;  // cal factor
      thing["batt"] >> outputValue(voltage);  //  send to dash or bucket
//  thing["batt"] >> outputValue(analogRead(A0));  // works but needs cal factor


void loop() {

Digging through past posts I found someone doing a cal for temp & humidity.
A slight mod to it works for me!

// data transmission
 thing["batt"] >> [](pson & out) {

   //calibration factors
   float cal_v = .01;   

   //data sending
   out = analogRead(A0) * cal_v; 

Time to move on to learning Endpoints :slight_smile:
Thank You Thinger IO !