Why my screen don't have image

After everything is connected and both network card lights are on,my screen still looks like the following. It seems that the receiving end has not received the information from the sending end. How can I solve this problem?

Ground:raspberrypi 4b
Air :raspberrypi zero

Do you have two TPLink TL-WN722N V1?

How do you have everything powered?

yes , my air and my ground both have TPLink TL-WN722N V1.
I power ground by this :point_right:

and power my air by the charger of my phone👉

I think that white charger is probably too weak. You should read the section in the gitbook regarding power supply. I think this is where your problem is

oh ! maybe ,I will buy other charger to have a try . thank you.

Hey! Sir,I I’ve replaced my white charger with a 5v3a charger. But I still see nothing in my screen .what should I do next :crazy_face:

Hi,Try to power on the air pi first,wait a few minutes, then power on the ground pi.

You are still powering those wifi cards really badly.


Especially the airpi… You should have it directly wired. Also are you absolutely sure those are “v1” cards?

also separation between cards of at least a meter is better… I know you probably put them close for a picture. But really fix your wiring.

Everyone thinks “oh this is just a wifi card that can be plugged in, why do I need to wire it”… the pi supplies voltages and amperages that are often too low for the cards to work at the high power settings openhd sets your cards. If it works without wiring it- you are just getting lucky

Finally just because the light is on does not mean its working right or powered right.

emmm…I will try to fix my wiring although it looks hard . I’m sure those are TPLink TL-WN722N V1

Cut that cable you have plugged in between the airpi and your wifi card. Then wire it like that

Also just so you know- those tplink v1 cards dont get very much range… They just are not very powerful as a tranmitter

You also will want to consider how you plan to control your rc aircraft as the video link with tplink cards is on 2.4g.

Hi, thank u ! buddy.I’ve solved my problem . But there is a new problem appear . After a few minutes of running the camera and being able to see the image, My screen turns green from normal. What causes this problem? How can I solve this problem