ComputerCraft EU Redstone Receiver

-- https://pastebin.com/BiL3Fi8P
    --modem=peripheral.wrap("back")
    local channel = 0
    local message = ""
    local returnChannel = 0
    rednet.open("back")
    term.clear()
    term.setCursorPos(1,1)
    print("ERROR: Sending computer isn't running startup program")
while true do
    channel, message, returnChannel = rednet.receive()
    term.clear()
    term.setCursorPos(1,1)
    print("Received Channel: "..channel)
    print("Received Message: "..message)
    --print("Received Return: "..returnChannel)
    if message == "start" then
        print("Sending redstone to: start")
        redstone.setOutput("bottom",true)
        redstone.setOutput("right",true)
        sleep(1)
    elseif message == "STOP" then
        print("Sending redstone to: STOP")
        redstone.setOutput("bottom",false)
        redstone.setOutput("right",false)
        sleep(1)
    end
end