arduino/esp8266
1
0
Fork 0
mirror of https://github.com/esp8266/Arduino.git synced 2025-04-19 23:22:16 +03:00
Code

doc: analogRead must not be called to frequently with WiFi is on (#7981)

Browse Source
This commit is contained in:
david gauchard 2021-04-14 19:40:11 +02:00 committed by GitHub
parent 1cc6960a55
commit 209e467120
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
doc/reference.rst
View File

@ -74,12 +74,17 @@ pin, except GPIO16. Standard Arduino interrupt types are supported:
Analog input
------------
**NOTE:**
Calling ``analogRead()`` too frequently causes WiFi to stop working. When
WiFi is under operation, ``analogRead()`` result may be cached for at least
5ms between effective calls.
ESP8266 has a single ADC channel available to users. It may be used
either to read voltage at ADC pin, or to read module supply voltage
(VCC).
To read external voltage applied to ADC pin, use ``analogRead(A0)``.
Input voltage range of bare ESP8266 is 0 — 1.0V, however some many
Input voltage range of bare ESP8266 is 0 — 1.0V, however some
boards may implement voltage dividers. To be on the safe side, <1.0V
can be tested. If e.g. 0.5V delivers values around ~512, then maximum
voltage is very likely to be 1.0V and 3.3V may harm the ESP8266.