Testprogram

-- Replace these with the actual monitor and modem addresses
local monitorAddress = "right"
local modemAddress = "left"

local monitor = peripheral.wrap(monitorAddress)
local computerID = os.getComputerID()

function drawProgressBar(x, y, percentage)
    monitor.setCursorPos(x, y)
    monitor.setBackgroundColor(colors.white)
    monitor.clearRow(y)
    monitor.setBackgroundColor(colors.blue)
    local width = math.floor(percentage / 100 * (monitor.getSize()))
    monitor.setCursorPos(x, y)
    monitor.write(string.rep(" ", width))
    monitor.setBackgroundColor(colors.white)
end

function readRFAndDisplay()
    while true do
        local energyInfo = peripheral.call(modemAddress, "getEnergyInfo")
        if energyInfo then
            local rfPercentage = math.floor((energyInfo.energyStored / energyInfo.maxEnergyStored) * 100)
            monitor.clear()
            drawProgressBar(1, 1, rfPercentage)
            monitor.setCursorPos(1, 2)
            monitor.setTextColor(colors.black)
            monitor.write("RF: " .. rfPercentage .. "%")
        end
        sleep(5)
    end
end

-- Main program
monitor.setBackgroundColor(colors.white)
monitor.clear()
monitor.setTextScale(1)
readRFAndDisplay()