RF Communication over ESP, BLE or other

[Ioannis]

I need to make radio remote control with this needed specs:

1. The remote controller should be light, small and low battery consumption
2. The range is not much important. Anything between 50-150 meters is OK
3. Receiver can be ON all the time
4. Transmitter should be sleeping if no key is depressed
5. Wake up and transmission should be completed under 100ms max.

Can the Bluetooth Low energy modules talk to each other?

or

Can the WiFi modules like ESP12 etc talk to each other like an RF tranceiver?

And if these are in sleep mode, how fast can wake up and complete a transmission?

Thanks,
Ioannis

[richard]

ble is lucky to get 10m
espnow is said to have that sort of range, not sure of wake up time. very low power sleep is fairly easy to do.
esp as wifi has a 20m range without some sort of assistance and takes 3 or 4 seconds to wake
rfm69 and the like can do it easily

[sayzer]

Ioannis,

What will you transmit? 1-byte at once? 1 bit?
Multiple bytes?

[Ioannis]

The project is about controlling small car for children. They are owned by renting shops.

These are electric remote controlled cars with one or two 12v/7a batteries, 2-5 motors like the ones in small rechargeable vacuum cleaners.

The one motor is for the steering, the rest for the wheels. Some are 4x4 so max 5 motors.

The problem is that these are bad chinese designs and the renting shop has major problem that the remote control of one car, interferes with the other, so it is dangerous when cars are near.

Usually the remote control is carried by the parent of the children in the car for the renting period, so he can prevent any accidents. The children also has control of the car but with lower priority.

My task is to design a new remote with the main specs on my #1 post.

The data sent can be kept at minimum, say 2-5 bytes at a time.

I have experience with ASK systems since I use them in my designs, but the delay is they introduce is too much.

Ioannis

[sayzer]

http://www.hoperf.com/modules/2.4g/RFM75.html


(http://www.hoperf.com/modules/2.4g/RFM75.html)

[Ioannis]

Well, this is promising!

Thanks Sayzer,
Ioannis

[richard]

what range ? they look very much like nrf24l01 . i don't get much over 6m under best conditions with them without
directional antenna

[Ioannis]

6m? that is not distance... that is besides!

Are you sure that your modules are OK? Seems too short. Even BT does it better.

From the Annex forum, Francesco (the developer of the Annex WiFi I assume) said that it is possible with the ESP modules. Use of the SLEEP command of the interpreter will put the module to sleep for almost zero current draw. Also Wake up and transmission is fast enough, possible through input trigger (button press etc). Have to try and see how it goes.

Ioannis

[sayzer]

6m? that is not distance... that is besides!

Are you sure that your modules are OK? Seems too short. Even BT does it better.

From the Annex forum, Francesco (the developer of the Annex WiFi I assume) said that it is possible with the ESP modules. Use of the SLEEP command of the interpreter will put the module to sleep for almost zero current draw. Also Wake up and transmission is fast enough, possible through input trigger (button press etc). Have to try and see how it goes.

Ioannis

For ESP, wake up could be fast but then it needs to connect via a protocol;
Using TCP type protocol, connection may take some time especially after when connection is lost and a reconnect is needed; If there is not a disconnection command, and it is a lost of connection, then is a mess.
If one ESP is operating in AP mode, and other is connecting to this AP as client, and later on, the client wakes up then, AP already had the mac of client in buffer; client will now try to reconnect. The messy pary starts there. It can not connect because AP thinks that the same MAC is already connected and does not give you access. Hello hell.

Let me re-state a statement here:


Experience is gained only in action!

Ioannis

[Ioannis]

ESPs are not communicating on TCP protocol.

Using ESP-NOW the communication, as Francesco says, is rapid.

Have not tried it yet. I have no experience on the ESP modules and need some reading before I understand how to do any flashing, connecting etc.

I have two ESP8266 modules from Ai and hopefully will soon put it on the breadboard.

https://cicciocb.com/annexhelp/V1.417//?topic=onudp#ESP-NOW

Ioannis

[sayzer]

ESPs are not communicating on TCP protocol....

Ioannis

ESP-NOW does not use TCP protocol. This is true, but ESP does.
NodeMCU also has TCP protocol.
Why there is no TCP in ESP-NOW, one may ask; I have no idea. Need to check further.


(https://tttapa.github.io/ESP8266/Chap05%20-%20Network%20Protocols.html)

[richard]

this will help

https://forum.arduino.cc/index.php?topic=551310.30


https://www.youtube.com/watch?v=6NsBN42B80Q

[sayzer]

Thank you Richard; It was a good video indeed.

Here is another one for ESP to ESP.
Surprising result; over 1KM comm distance.


https://youtu.be/ekSsi83-x8M