How to read RC input in Lua?

kobaf · January 20, 2021, 8:49am

Hi everybody,

There is no binding to read RC pwm input in Lua in current stable version. And also there’s no explanation how to convert c++ declarations into binding description strings. So could anybody help with subject?

Thank you in advance.

Eosbandi · January 20, 2021, 10:24am

You have to use 4.1-dev.

github.com

ArduPilot/ardupilot/blob/master/libraries/AP_Scripting/examples/RCIN_test.lua

-- example of getting RC input

local scripting_rc_1 = rc:find_channel_for_option(300)
local scripting_rc_2 = rc:find_channel_for_option(301)

function update()
  pwm1 = rc:get_pwm(1)
  pwm2 = rc:get_pwm(2)
  pwm3 = rc:get_pwm(3)
  pwm4 = rc:get_pwm(4)
  gcs:send_text(0, "RCIN 1:" .. tostring(pwm1) .. " 2:" .. tostring(pwm2).. " 3:" .. tostring(pwm3).. " 4:" .. tostring(pwm4))

  -- read normalized input from designated scripting RCx_OPTION
  if scripting_rc_1 then
    gcs:send_text(0, "Scripting in 1:" .. tostring(scripting_rc_1:norm_input()))
  end

  -- read switch input from second designated scripting RCx_OPTION
  if scripting_rc_2 then
    local sw_pos = scripting_rc_2:get_aux_switch_pos()

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kobaf · January 20, 2021, 10:50am

Unfortunately I cannot use 4.1-dev as it causes error 0x8000 on boot which I can’t fight till now. (PreArm: Internal errors 0x8000 l:404 main_loop_stk after upgrading to latest 4.1.0-dev). But I’ve made simple kludge: copied get_pwm member of RC_Channels class from master branch to Rover 4.0 as well as relevant strings in bindings.desc. Recompiled and works ok.