Analog input RSSI

ArduCopter
1

Hello I want to use the RSSI pins (for example AUX3) to read the voltage from a transducer. Because it is transducer it needs 5V in order to produce the voltage measurement (0-5V) and a GROUND. I use at the moment CUAV v5+ I make the parameters settings as described in site but I do not get 5 volts (there are ±S). I am following the instructions about setting parameters. Do I miss something?

2

I decided to use ADC port instead at the moment with 6,6V pin and I will check in future about RSSI.

Now I want to use LUA read the value of ADC port 6,6V and then act accordingly (show message to operator). The problem is that I am confuded as others say you can not do it through LUA and others say you can. Anyway I tried code

local analog_in = analog:channel()
if not analog_in:set_pin(14) then -- typically 13 is the battery input
  gcs:send_text(0, "Invalid analog pin")
end

function update()
  gcs:send_text(0, string.format("voltage: %0.2f", analog_in:voltage_latest()))

  -- analog_in:voltage_average() the average voltage since the last call
  -- analog_in:voltage_latest() the latest voltage reading
  -- analog_in:voltage_average_ratiometric() the average ratiometric voltage (relative to the board 5v)

  -- pwm_in:get_pwm_us() the latest pwm value in us
  -- pwm_in:get_pwm_avg_us() the average pwm value in us since the last call

  -- gpio:read(pin)
  -- gpio:write(pin, state)
  -- gpio:toggle(pin)


  return update, 1000
end

return update()

from script libraries/AP_Scripting/examples/analog_input_and_GPIO.lua

and it shows message can not allocate memory.

Could you help me please?