I'm making a smart home system using nodeMCU, and I need to store and retrieve data from the module. I used the following function.
function save_settings(name,value)
file.remove(name)
file.open(name,"w+")
file.writeline(value)
file.close()
end
It works but it's slow and the NodeMCU crashes if I trigger the above function rapidly... Sometimes requiring a FS format to be able to use it again.
So my question is: is there any other way to make variables persistent between restarts?
I'm using the latest firmware, 0.9.6-dev_20150704, the float version (https://github.com/nodemcu/nodemcu-firmware/releases)
This code took 62-63 ms to complete at first, and seems to add a few fractions of a millisecond with each successive run of the code, after a few hundred executions, it was up to almost 100 ms. It never crashed on me.
function save_setting(name, value)
file.open(name, 'w') -- you don't need to do file.remove if you use the 'w' method of writing
file.writeline(value)
file.close()
end
function read_setting(name)
if (file.open(name)~=nil) then
result = string.sub(file.readline(), 1, -2) -- to remove newline character
file.close()
return true, result
else
return false, nil
end
end
startTime = tmr.now()
test1 = 1200
test2 = 15.7
test3 = 75
test4 = 15000001
save_setting('test1', test1)
save_setting('test2', test2)
save_setting('test3', test3)
save_setting('test4', test4)
1exists, test1 = read_setting('test1')
2exists, test2 = read_setting('test2')
3exists, test3 = read_setting('test3')
4exists, test4 = read_setting('test4')
completeTime = (tmr.now()-startTime)/(1000)
print('time to complete (ms):')
print(tostring(completeTime))