Webhook error code 400

my arduino is sending a string via virtual pin v0 to an LCD widget . I.put up a webhook widget and created a new channel online. no big clue how a string data could be visualized in webhook .

I’m but troubled with url part . I selected v0 pin in webhook and pasted a url like this


i don’t know about the part after the api id in that url .

error 400 , when I run it ! first time noobie.

plz help

Have you tried reading the documentation?


sir , I checked… I’m stuck with this part-

Use standard Blynk placeholders for Pin Value in the body or URL, for example:


I’ve code :

Blynk.virtualWrite(v0, val);

I’m really confused with the (pin) part and url

Can you explain more about exactly what you’re trying to achieve?

Where is the data coming from, what is the role of the LCD, and what is the reason for using Thingspeak?

Are the LCD and Webkook widget sharing the same V0 pin?


I’m just trying to send some data - strings like hello or digits like 0s and 1s …

all these data passes through Virtual pin V0 , then displays in LCD widget (works fine)

I just used a web hook widget and edited the virtual pin to V0 in the webhook widget also .
I don’t really find an idea how should I put the url inside the widget . plz help

I’ve a thinkspeak account , don’t know wether it will work for strings kinda datas

I still don’t understand what you are trying to achieve.

Are these strings hard-coded into your Arduino code?
What is Thingspeak being used for?


thinkspeak is just a cloud platform .
I’m confused how to put up the url or define pin in the webhook widget !

I’m virtual writing through v0

I can’t help you if you don’t answer my questions.


Post your complete sketch, and perhaps some screenshots from your widget with settings. It’s always much easier to get help when all relevant information is provided.

HTTP Error code 400 is a Bad Request, e.g. a malformatted URL.

Maybe this can help you? Webhook and multiple values in Thingspeak (again) SOLVED

Good luck!