Hi everybody! please help!
i try to use INA and esp8266 to measure voltage and current values, control max current or max voltage. When I turn on or off the CVmode switch, change the slide value, nothing changes, it always shows cvmode=1, Slide value=0. Why???
• ESP8266 with INA219
• Blynk APP on Smartphone OS (iOS 3.5.4 and Android 1.9.1(122))
• Blynk Library version 1.2.0
• My sketch code is like that.
[Code deleted at the request of @thanhviet228]
there is my dashboard and datasteam
Can you post screenshots of how you’ve set-up your switch and slider widgets?
You provided a screenshot of your mobile dashboard, but when I asked for details of how you’ve configured these widgets you’ve provided a screenshot of the web dashboard widgets.
I’m sorry. they are exactly the same
Okay, there’s a few things wrong…
1 - Variable Scope
cvmode defined as a global variable of type Integer at the top of your code…
int cvmode = 0;
but you are then declaring a local integer variable with the same name inside your
This means that the local version of
cvmode isn’t visible outside of
To fix that, change your
BLYNK_WRITE(V7) to this…
cvmode = param.asInt(); // <<< `int` removed from beginning
Serial.print("V7 cvmode value is: ");
You also need to do the same thing with
setpercent which you are re-declaring as local within
2 - Difference between “=” and "=="
void ina219values() you have this…
The problem is that
if (cvmode = 0) should be
if (cvmode == 0)
if (cvmode = 1) should be
if (cvmode == 1)
When you use
cvmode = 0 it means “set
cvmode to 0”, so
cvmode is being set to 0, then in the next piece of code it’s being set to 1 - which is why
cvmode is always 1 in your serial monitor.
Double equals signs ("==") means “compare the two values” so
if(cvmode==0) means "compare the current value of
0, if they are the same then the
if statement evaluates as
Thank you very much. I did exactly as you said and it worked perfectly.
Thank you all for creating this great forum.
can you delete my code ? i don’t want my source code to be copied.
I’ve deleted your code on this occasion, but I seriously doubt that anyone would want to copy it as it’s so badly written.
Bear in mind for the future that this is a public forum, so code or other information posted is being placed in the public domain.