ESP8266 Tcp-to-uart with reprogramming ability - esp8266

Question

I'm using this example from nodemcu repo:
uart.setup(0,9600,8,0,1,0)
sv=net.createServer(net.TCP, 60)
global_c = nil
sv:listen(9999, function(c)
if global_c~=nil then
global_c:close()
end
global_c=c
c:on("receive",function(sck,pl) uart.write(0,pl) end)
end)
uart.on("data",4, function(data)
if global_c~=nil then
global_c:send(data)
end
end, 0)
But, since I'm using uart module, I'm no longer able to communicate with my chip via LuaLoader and can not upload updated init.lua files. Instead, I have to put chip into flash-upload mode, then flash initial nodemcu firmware and then my updated init.lua. Too much steps.
How can I retain ability to communicate via LuaLoader? I've tried something like this:
uart.on('data', '\n', handleUartResponse, 0)
...
...
function handleUartResponse(response)
if response == 'flash\n' then
g_flash = true
toggleOutput(true)
uart.write(0, 'flash mode')
elseif response == 'endflash\n' then
g_flash = false
uart.write(0, 'normal mode')
toggleOutput(false)
elseif g_flash then
node.input(response)
else
if g_conn ~= nil then
g_conn:send(response, function(sock)
closeConnection(sock)
g_conn = nil
end)
end
end
end
function toggleOutput(turnOn)
if turnOn then
node.output(nil, 1)
else
node.output(silent, 0)
end
end
It prints flash mode and normal mode in another serial terminal, but it doesn't work in LuaLoader. I think the problem is in uart setup, maybe it should not be \n, but other condition, I don't know what.

Answer 1

Got it! Not sure if it is the best option, since I'm new to lua, but it works.
function handleNormalMode(response)
if response == 'flash\r' then -- magic code to enter interpreter mode
toggleFlash(true)
else -- tcp-to-uart
if g_conn ~= nil then
g_conn:send(response, function(sock)
closeConnection(sock)
g_conn = nil
end)
end
end
end
function ignore(x)
end
function uartSetup(echo)
uart.setup(0, 115200, 8, 0, 1, echo)
end
function toggleFlash(turnOn)
if turnOn then
uart.on('data') -- unregister old callback
uartSetup(1) -- re-configure uart
uart.on('data', 0, ignore, 1) -- this allows lua interpreter to work
node.output(nil) -- turn on lua output to uart
uart.write(0, 'flash mode') -- notify user
else
node.output(ignore, 0) -- turn off lua output to uart
uart.on('data') -- unregister old callback
uartSetup(0) -- re-configure uart
uart.on('data', '\r', handleNormalMode, 0) -- turn on tcp-to-uart
uart.write(0, 'normal mode') -- notify user
end
end
I'm calling toggleFlash(false) at the beginning of script. Then, typing flash\r enters lua interpreter mode and to switch back I'm just typing toggleFlash(false) and it works! That simplifies updating init.lua every time.