This script creates a rudimentary sine wave on DAC0.

LJ - 07.30 - sine_wave_DAC0.lua

--[[
LJ - 07.30 - sine_wave_DAC0.lua

This script creates a rudimentary sine wave on DAC0.

Components
----------

- LabJack T4
- Oscilloscope
  - GND probe to GND
  - Signal probe to DAC0
- Wires
- Breadboard

Course
------
Data acquisition and automation with LabJack
https://app.techexplorations.com/courses/labjack/

--]]

print("Output sine wave. Analog output is DAC0.")

local OutputVoltage = 0

local mbWrite=MB.W

--If max amplitude is needed, use 2.5V centerline and 2.25V amplitude. VS ranges from 4.75-5.00V depending on setup.
local amplitude = 2           --amplitude in volts (maximum of 5V for VS)
local offset = 2.5            --offset, or centerline voltage in volts
local frequency = 100         --frequency in Hz
local rad_step = .01          --radians per step. A smaller number increases waveform resolution

local timer_ms = 1000 / (2 * (frequency / rad_step) )
local rads = 0

LJ.IntervalConfig(0, timer_ms)                   --set interval to 10 for 10ms
local checkInterval=LJ.CheckInterval

while true do
  if checkInterval(0) then                 --interval completed
    if rads >= 2 then
      rad_step = rad_step * -1
    end
    OutputVoltage = ( (math.sin(rads) ) * amplitude) + offset
    rads = rads + rad_step
    mbWrite(1000, 3, OutputVoltage)            --Set DAC0. Address is 1000, type is 3
    --print(OutputVoltage)
  end
end