Today I installed NodeMCU on one ESP8266 module.
I made a simple telnet server (logging in to the AP is already done and connected)
srv=net.createServer(net.TCP,7200)
srv:listen(23,function(conn)
conn:on("receive", function(conn,telnetdata)
print(telnetdata)
conn:send("Got it\r\n")
end)
conn:on("sent",function(conn)
print("[Sent]");
--conn:close();
--collectgarbage();
end)
end)
I can telnet into the ESP8266 using Putty and I can send static data back to Putty (conn:send("Got it\r\n")).
What I want to do is to send data to Putty from the esp serial port (UART). I've googled for an example without success. BTW I'm using ESPlorer to program the ESP and to send data back to putty.
Instead of using conn:send("Got it\r\n") I want to dynamically type the response. I've tried uart:on callback but I haven't fully understood how it works.
NodeMCU has an "official" Telnet example in the repository. However, that one is also WiFi/socket-based.
If you're connected to the device through ESPlorer (i.e. serial/UART) you can't open another serial connection. See https://stackoverflow.com/a/36779799/131929 for details.
Marcel thank you for your answer.
The link posted is not exactly what I need but it offered good info.
I finally came up with this code that works as a simple bridge between putty and a micro controller (arduino mega 2560 in this case)
socket = net.createServer(net.TCP,7200)
socket:listen(23,function(c)
c:on("receive",function(c,l)
uart.write(0, l)
end)
c:on("disconnection",function(c)
-- not yet implemented
end)
uart.on("data", 0,
function(data)
c:send(data)
end, 0)
end)
Related
I have 2 types of ARDUINO-cards. ATMEGA 2560 and ATMEGA 328P.
In my Delphi7 (XP64 sp2) I have modified the JvHidDeviceController Unit to show the PID/VID's of the abovementioned Cards. That works perfectly. And with the use of the TComPort unit I can communicate with the selected card. No problems here.
And here is the problem:
I connect my AVR MARK II (usb-tiny). System "says" OK.
(When I run the ARUINO program I have no problems communicating with the connected card.)
I run the Delphi program (JVHidDeviceController Unit), the 2560 and 328p PID/VID appear in a LIST-box but NOT the AVR-MARK II.
I Wonder why ? Please help.
After a search on the WWW I discovered, that the UNO (328P) could be turned into a ISP programmer. And by doing so I solve 2 (sub-)problems. I got the code ("bootloader") and the UNO Stills responds to the JVHidDeviceController requests. (Final solution in reach.. ) Kris
im trying to connect my esp32 microcontroller via wifi. But it doesnt work. I followed the tutorial on https://docs.micropython.org/en/latest/esp32/quickref.html#networking step by step and watched a lot of youtubevideos.
my code looks like this:
import network
wlan = network.WLAN(network.STA_IF) # create station interface
wlan.active(True)
print(wlan.scan())
wlan.connect('my_wlan_ssid', 'my_wlan_password')
print(wlan.isconnected())
print("Wlan is connected: ", wlan.isconnected())
print("My Wlan config: ", wlan.ifconfig())
here i add a picture from my command linde from the Thonny editor
Command line from Thonny editor
The funny thing is, the webinterface from my router shows me the connection to the esp32 controller with his ip-address.
I also tried it with a mobile-hotspot from my mobilephone. My mobilephone shows me the connection with the esp32, but the esp32 doesn't recognize the wlan connection
So why is it so?
Do i something wrong?
Seems like you are not letting the network actually make the connection.
wlan.connect('my_wlan_ssid', 'my_wlan_password')
takes time and as shown in the linked reference, wlan.isconnected() should be called in a while loop to ensure that it exits only if it is connected. (you could of-course do better management)
So how about you do this:
import network
sta_if = network.WLAN(network.STA_IF)
if not sta_if.isconnected():
print('connecting to network...')
sta_if.active(True)
sta_if.connect('<essid>', '<password>')
while not sta_if.isconnected():
pass
print('network config:', sta_if.ifconfig())
As per your own link
I am trying to acquire rs232 data from a device connected to the ESP8266 (data will then be sent our via http/wifi).
I am using max3232 IC to provide the necessary 3.3v TTL to the ESP8266.
I have have connected the max3232 (pin 12) to GPIO pin 13 (rx) on the ESP8266 (I am only receiving data not sending data, so only the rx pin is connected).
The code i am using:
--
--file: test2.lua
--
tst2 = require "tst2"
tst2.start()
--tst2.lua (testing script)
local module = {}
function module.start()
print("in tst2.start")
uart.alt(1) --use alt GPIO pin 13 (Rx)
uart.setup(0, 9600,8, uart.PARITY_NONE, uart.STOPBITS_1,0)
uart.on("data",10,
function(data)
file.open("data.tmp", "w+")
file.writeline("starting")
for i=1,10 do
file.writeline(string.byte(string.sub(data,i,i)) )
end
file.writeline("from uart: ", data)
file.writeline("finished")
file.close()
end, 0)
uart.alt(0) --switch back to standard Rx/Tx pins
end
return module
The rs232 device connected to the ESP8266 is putting out a single alphabetic character every 3 seconds, however the data written to file (data.tmp) is as follows
starting
10
13
10
13
10
13
10
13
10
13
from uart:
finished
file.close()
Problems:
1- The rs232 device is not issuing any newln or cr characters, but these are appearing in the data file.
2- the string "file.close()" is being written to the data file, and looks like it is the actual lua command that follows the final file.writeline command.
3- the alphabetic data is not appearing in the data file.
4- switching back to the standard uart pins via uart.alt(0) does not work (the ESP8266 must be rebooted - this is not a major issue as the standard uart pins are only used during debugging).
I am writing the rs232 data to a file instead of simply printing it out on the screen (I am using ESPlorer v0.2.0) because the uart.alt(1) command redirects the serial port to the alternative ESP8266 gpio pins.
I think I am doing something fundamentally wrong with the uart set up, but i can't tell what it is.
SOLVED:
It appears that you can't connect the ESP8266 to both the serial port for debugging (e.g. the serial port on a pc running ESPlorer) and also have the alternate serial pins (ESP8266 GPIO 13 and 15) connected (to an external serial device) at the same time.
The nodemcu uart.alt() function does not appear to "turn off" the standard serial i/o pins.
Disconnecting the pc from the standard serial i/o pins solved the problem (debugging becomes an issue, but there are work-arounds to resolve this).
(updated) one workaround is to use a simple telnet server to interact with the lua interpreter. you can either connect the ESP8266 to your wifi router or, even better, set it up as an access point (AP) so that all you have to do is to connect your computer to it and then simply telnet in (to the gateway's IP). so, in addition to the telnet code, you'll need set up the AP in your init.lua. full code for the telnet server and the AP setup is below. A nice benefit is that I can program and monitor the ESP8266 from my phone using an off-the-shelf telnet app!
jj = [[
sock = 22 -- just a placeholder, so it stays global. may not be needed.
-- use sock:send("hello") to insert your own custom output to the client.
telnet_srv = net.createServer(net.TCP, 180)
telnet_srv:listen(2323, function(socket)
local fifo = {}
local fifo_drained = true
local function sender(c)
if #fifo > 0 then
c:send(table.remove(fifo, 1))
else
fifo_drained = true
end
end
local function s_output(str)
table.insert(fifo, str)
if socket ~= nil and fifo_drained then
fifo_drained = false
sender(socket)
end
end
sock = socket -- make the socket globally available.
node.output(s_output, 0) -- re-direct output to function s_ouput.
socket:on("receive", function(c, l)
node.input(l) -- works like pcall(loadstring(l)) but support multiple separate line
end)
socket:on("disconnection", function(c)
node.output(nil) -- un-regist the redirect output function, output goes to serial
end)
socket:on("sent", sender)
print("Welcome to NodeMCU world.")
end)
]]
file.open("telnet.lua", "w")
file.write(jj)
file.close()
jj = [[
wifi.setmode(wifi.STATIONAP);
wifi.ap.config({ssid="ESPtest",pwd=""});
print("Server IP Address:",wifi.ap.getip())
dofile("telnet.lua")
]]
file.open("init.lua","w")
file.write(jj)
file.close()
node.restart()
output:
Server IP Address: 192.168.4.1 255.255.255.0 192.168.4.1
>
I'm trying to securely connect ESP8266 to MQTT Azure Protocol Gateway broker on cloud or local computer (tried both) like this (not important - connection works correctly):
m = mqtt.Client("{deviceId}", "3600", "{iotHub}/{deviceId}", "{SASToken}")
...
m:on("message", function(conn, top, data)
print(data) -- EMPTY string here!
end)
...
m:connect({IP}, 8883, 1, function(conn)
m:subscribe("devices/{deviceId}/messages/devicebound/#", 1, function(conn)
...
end)
end)
ESP connects to server and handshake is completed successfully. When I publish some data, I can read it on server properly, it is OK. I subscribe to topic without problems. When I send data in cloud-to-device message from server to ESP to subscribed topic, 'on message' event is called but data attribute passed to the function is EMPTY string.
I'm using latest NodeMCU master build based on 1.4.0 SDK (tried both integer and float version). I can't turn on debugging, because i don't have NodeMCU developer yet.
I tried following:
dev version - not help
free memory up to 32kB - not help
captured packets with WireShark: packets contain encrypted data with some lenght, so it is not empty and packet size is less than 2kB buffer size
Can someone please advise me where could be a problem or how to debug it for more info? I would approciate any ideas. Thank you.
EDIT:
I've tried debug mode, and there is nothing interesting on output:
enter mqtt_socket_received.
MQTT_DATA: type: 3, qos: 0, msg_id: 0, pending_id: 0
enter deliver_publish.
string
userdata: 3fff3e88
devices/ESP/messages/devicebound
<- here should be printed data
On
leave deliver_publish.
receive, queue size: 0
leave mqtt_socket_received.
enter mqtt_socket_timer.
timer, queue size: 0
keep_alive_tick: 71
leave mqtt_socket_timer.
enter mqtt_socket_received.
MQTT_DATA: type: 7, qos: 1, msg_id: 8813, pending_id: 0
receive, queue size: 0
leave mqtt_socket_received.
This may be stupid but sometimes lua expects specific names in some functions.
Change this
function(conn, top, data)
for this
function(conn, topic, data)
I have worked previously with mqtt in lua with password protection, and i had to drop it beacuse i wasnt recieving the message content either, however i think mine was due to the amount of messages i was recieving/delivering. I also changed broker from mosquitto to mosca.
I hope you find a fix soon and please share it we might be able to use it to :)
I have a software that prints out to a thermal printer connected to the comm port, the code below works well.
Open "COM3:" For Output Access Write As #1
Print #1, Space(8) & "FRAKAS LTD"
Print #1, Space(7) & "P.O. Box 7678 SHIMONI"
...
...
Close #1
Now I want to print on the same comm port but from a different computer on the network, is it possible?
You can redirect the serial port across the network by running software at each end. There is some info on Wikipedia here about some solutions - I haven't tried any.
We have used ethernet to serial converters from Moxa - these redirect a local COM port to a remote one without any PC at the remote end. One example is here
if the printer is availabe then you can use the following to prepare text to be printed :
printer.print "text"
to start the actual printing you use the following :
printer.enddoc