PowerMon2 v0.7

os.loadAPI("ocs/apis/sensor")
local power = sensor.wrap("left")
local net = peripheral.wrap("back")
local mon = "monitor_0"
if ( power == nil ) then
    print("No sensor!")
    os.exit()
end
if ( net == nil ) then
    print("No network!")
    os.exit()
end

-- coordinates of blocks to monitor
local locations = {"-1,-1,0","0,-1,0","1,-1,0","-2,-2,-1"}

function displayPercent(percent)
    net.callRemote(mon,"clear")
    net.callRemote(mon,"setCursorPos",2,3)
    --local display = string.format("%.2f",percent)
    local display = string.sub(tostring(percent),1,4) .. "%"
    net.callRemote(mon,"write",display)
end


function getEnergySpace()
    local location
    local total = 0
    local totalStorage = 0
    for i,location in ipairs(locations) do
        local blockInfo = power.getTargetDetails(location)
        if ( blockInfo == nil ) then
            print("Can't get block info " .. location)
            exit()
        end
        total = total + blockInfo["Stored"]
        totalStorage = totalStorage + blockInfo["Capacity"]
    end

    percentTotal = 100 * total / totalStorage

    displayPercent(percentTotal)

    return percentTotal
end


while true do
    if ( getEnergySpace() < 95 ) then
        rs.setBundledOutput("right",colors.white)
        os.sleep(2)
    else
        rs.setBundledOutput("right",0)
        os.sleep(10)
    end
end