Need Hardware list and tipps for 5-Dot-Matrix printing with Wifi-Modules

Thread Starter


Joined Dec 8, 2016
Hello guys
I just received a project from my local Soccer-Club to be able to print letters on the play field (grass-surface).
Mainly for cheering purposes, maybe also for advertisement later on.
The idea is pretty straight forward:

There are 5 RC-Cars with down facing spray cans, used as printers [-P-] as shown below.

Those 5 RC-Cars have all the same specs, this means you can expect one defined speed V.



(I hope it is obvious that this is going to write "COOL" ^^)

All those "O" 's represent a spray-puff and thus generating letters with this so called 5-Dot-Matrix method.
The challenge is to make it wireless (WiFi).
I was thinking of getting:
5* ESP8266 v-07 ( I choose v-07 to be able to add an antenna if increased range is needed in the future)

1* Arduino Uno, this one will be carry the code for the pre-selected words. (This can also be carried by RC-Car-3 as so called Leader/Commander)

5* Servos to interact with the spray cans to create those puffs

5* 3.3V Power supplies (Maybe Coin-Cell battery) for the ESP8266's

1* Battery for the Arduino Uno
But I am not sure if i can even work with this setup.

I mean I need to be able to connect everything like this (unless someone tells me otherwise):

Spray-can - Servo - ESP8266 = RC-Car-1

Spray-can - Servo - ESP8266 = RC-Car-2

Spray-can - Servo - ESP8266 - Arduino Uno = RC-Car-3

Spray-can - Servo - ESP8266 = RC-Car-4

Spray-can - Servo - ESP8266 = RC-Car-5

As mentioned the Arduino Uno contains the commands for all the other RC-Cars. This means that ESP8266 connected to that Arduino needs to be able to independently control (over WiFi) 5 Servos.
Servo from RC-Car-1 & RC-Car-2 & RC-Car-4 & RC-Car-5 & its own servo. Is it even possible to connect one ESP8266 with 4 other ESP8266 over WiFi at the same time? Does it even have to be at the same time? I could perhaps add delays (sleep-times) with experimenting...
Is there already a code for 5 Dot-Matix Printing?

Thank you very much for your attention

Best regards.


P.S. : It has to be over WiFi with 5 independent RC-Cars. I know it could make my project way easier if i just added a long stick of PVC-Pipe and made wired connections to each Servo and mount that on rails or something, but this needs to be versatile. :)

Thread Starter


Joined Dec 8, 2016
Hi there thanks for the quick reply. I actually did test 5 big and heavy RC-Cars which are very good at keeping the pace and there was no difference on any vehicle after 100 m test run. So I checked that problem. The main reason for insisting on RC-Cars is that it has to be able to make bigger letters if needed = Bigger distance between each vehicle... I can't do that with a wired connection e.g. PVC-Pipe rail mount construction. And it would also be much more fun to see those cars making the letters :)