Lua - nil value error

Question

I get the following error message from nodeMCU on esp8266 : attempt to call field "adc.force_init_mode" (a nil value). Can somebody point out the mistake please?

if adc.force_init_mode(adc.INIT_ADC) 
  then
    node.restart()
  return
end
val = adc.read(0)
print("Input number:", val )
val2 = 5000000 - (val*5000000/1023)
print("R (ohm):", val2 )

Do you need any more info? If not, consider [accepting (and/or upvoting) the answer](http://meta.stackexchange.com/questions/5234/how-does-accepting-an-answer-work) so that SO can mark this as answered. — Marcel Stör, Sep 15 '16 at 13:55

Marcel Stör · Accepted Answer · 2016-09-10T18:40:44.560

2

Your firmware does either not have the ADC module compiled in or it's got an ADC module without the force_init_mode function.

Therefore, build a recent firmware and flash it to upgrade your current firmware.

edited Sep 10 '16 at 18:40

answered Sep 10 '16 at 17:13

Marcel Stör

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wouldn't you get an error for indexing adc then? adc obviously is a table in his version. Maybe some old version of the adc module that does not implement force_init_mode? Fix is the same of course. – Piglet Sep 10 '16 at 17:54
Yes, but I doubt the error message in the description above is 100% accurate. `http.foo()` yields "attempt to call field 'foo'..." while `bar.foo()` yields "attempt to index global 'bar'". Note that in the OP's question it says "...field 'adc.force_init_mode'" (extra 'adc.'). I'll update the answer anyway. – Marcel Stör Sep 10 '16 at 18:37
oh totally missed that :) – Piglet Sep 10 '16 at 18:57
Thank you! I have problem in uploading built firmware...I'm working on that! – hoody Sep 17 '16 at 08:07

Lua - nil value error

1 Answers1