ESP8266: testing deep sleep & interrupts !?


This weekend I’ve been testing one of my ESP-12 module for more than just a few minutes; more like a few hours. Just to see how ‘robust’ the ESP8266 actually is. The story about ‘zombie mode‘, where the module didn’t restart after the deep sleep period had ended, made me curious whether the ESP8266 was stable enough (to use at all).

So I created these 2 scripts to make it do something useful for a change:

init.lua:

FileToExecute="gettemp.lua"
l = file.list();
for k,v in pairs(l) do
  if k == FileToExecute then
    print("*** You've got 5 sec to stop timer 0 ***")
    tmr.alarm(0, 5000, 0, function()
      print("Executing ".. FileToExecute)
      dofile(FileToExecute)
    end)
  end
end

gettemp.lua:

require('ds18b20')

serv_ip = '192.168.10.168'
serv_port = 8001
gpio4 = 2
interval = 20000000
ds18b20.setup(gpio4)

function getTemp()
  temp = ds18b20.read()
  conn = net.createConnection(net.TCP, 0)
  conn:on("connection", function(socket)
    socket:send(""..node.chipid().." "..tries.." "..temp.."\r")
  end)
  conn:on("sent",function(conn)
    conn:close()
  end)
  conn:on("disconnection", function(conn)
    node.dsleep(interval-tmr.now(), 0)
  end)

  conn:connect(serv_port, serv_ip)

end                   

function connect()
  tries = tries + 1
  wifi_ip = wifi.sta.getip()
  if wifi_ip == nil then
    if tries < 5 then
      tmr.alarm(0, 1000, 0, connect)
    else
      node.dsleep(interval-tmr.now())
    end
  else
    getTemp()
  end
end

tries = 0
connect()

Nothing spectacular – it reads a DS18B20 sensor, sends the temperature and some other data to a NodeJS TCP server, goes to deep sleep and wakes up 20 seconds after the previous wake-up, so that the module does this 180 times per hour. It has been running since Friday night.

ESP8266 measuring DS18B20 and going to deep sleep

But then I found another interesting post about deep sleep and interrupts. And if my interpretation is right, this could be what I’ve been looking for – I just had to try it out:

You can easily esp8266 wake from a deep sleep. Just bring on to the RST short negative pulse. I use it.

 

Well…it works! (on a ESP-12 that is, haven’t tested any other model).

ESP8266 wake-up wire

 

Whenever the black wire at the bottom of picture makes contact with the RST pin and effectively pulling it to GND, the ESP8266 wakes up – this needs further research! 🙂

For now, I resumed the reliability test for another night.