What's the smallest, easiest to use, cheap.. Way to wirelessly communicate between two Arduinos?
Not a lot of data. I just need to get a intermittent stream of data over to a tiny display.
Thanks!
-jim lee
What distance? 3ft? 10ft? 100ft? A mile?
Will they be in different rooms?
Will they have direct line of sight?
Will you be holding one while the other transmits or receives?
How will they be powered?
The easiest would probably be IR, the most reliable would probably be Bluetooth or WiFi though not cheap. (depends on the model really)
Another is RF but typical Arduino compatible modules are usually one way.
Longer distances require more power and bigger antenna. Unless you use WiFi, then it can be from anywhere there is adequate connectivity.
I forgot a laser pointer and a photodiode, that is a possibility too.
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what is the distance between modules, the environment (walls, trees, etc) and how much data/second
if you have local WiFi coverage or the devices are within 10metres or so of each other the ESP32 is cheap (£about £7 on Ebay in UK) and has onboard WiFi, Bluetooth Classic and BLE
it is supported by the Arduino IDE - see installing-the-esp32-board-in-arduino-ide
For some (special) use cases, transferring the data manually on an SD card could be an option and seems to be one of the few suggestions so far missing in the other responses to your question.
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D1 Mini?
Is that cheap enough?
or a ESP32-S3-Zero mini cost about £7 in UK
With only that information provided, IR-LED and receiver.
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Espnow combines all three requirements.
OK, more info.
A) The plan is on using it on a boat.
B) One unit is powered off the 12V NMEA2000 network inside the boat (fiberglass balsa cored).
C) Other unit is hopefully to be in the form of a wristwatch with a tiny display on it.
D) The current boat is 35 feet in length. So, say 40 foot range as a starting point?
E) In order of importance #1 Small #2 Easy interface. Both FAR outweighs #3 cost.
F) Data rate is maybe a hundred bytes per second range? Probably less.
The bits I already have..
The CAN/NMEA network interface hardware. Yes, that's a teensy hooked to it. This it the bit that's going to live in the boat. Tested and working.
The network code : https://github.com/leftCoast/LC_llama2000
This is the cool little display I want to use on the wristwatch. From what I read, the library I already have should work with this. But I've not tried wiring it up yet. Just got it.
And the boat. This bit is well tested. It works.
So I read the info off the network. Then display it on my wrist. That is what I would like to accomplish.
IR would be out because too much stuff can get in the way.
Wifi is out because there will be none.
The data rate will be very low. I update the info every few seconds or so.
What do you think?
-jim lee
What are the specs on that display and how is it wired?
I would say RF or Bluetooth would be your best options.
Hello jimLee
Take a look here to get some ideas:
IF at all possible I'd like to steer clear of the ESP boards. I would rather add some sort of wireless to something like a teensy or possibly a trinket.
The display is SPI.
Here are the specs : https://wiki.dfrobot.com/SKU_DFR0995_1.47inches_IPS_LCD_Display_Module
-jim lee
How about one of these, Seeed Studio XIAO ESP32-C3 WiFi Bluetooth Development Board Module
It’s very small, it has Bluetooth built in and it should be more than enough for that display
Can a pair of those Seeed things communicate with each other?
How about this one? Very small. But I have no idea what it takes to make it alive and happy. https://www.seeedstudio.com/MDBT42Q-nRF52832-based-BLE-module.html?qid=eyJjX3NlYXJjaF9xdWVyeSI6IioiLCJjX3NlYXJjaF9yZXN1bHRfcG9zIjozLCJjX3RvdGFsX3Jlc3VsdHMiOjMsImNfc2VhcmNoX3Jlc3VsdF90eXBlIjoiUHJvZHVjdCIsImNfc2VhcmNoX2ZpbHRlcnMiOiJzdG9yZUNvZGU6W3JldGFpbGVyXSAmJiBjYXRlZ29yeV9pZHM6WzIwMjVdICYmIHF1YW50aXR5X2FuZF9zdG9ja19zdGF0dXM6WzFdIn0%3D
It seems like they have a processor built into these things but I've no idea how they set them up. I'm pretty far outta' my yard on this stuff.
-jim lee
Yes they can and they can even use ESPNow. As for that other board, I am not familiar with it but it should be fine too. I am not sure how you would use it and the pins are rather close together so soldering will be tough.
Both options are worth looking into.
Ok, but that's going against your first priority, to be small.
It hard to beat something like Xiao Esp32-c3 for the size and easy development. I's a fraction of Teensy and have wireless built in.
Also you have options for wifi, esp-now and bluetooth. And you don't need "external" wifi connection to use wifi.
The simplest and cheapest way to wirelessly communicate between two Arduinos is using nRF24L01 modules. They are small, low-power, and great for short-range communication. If you need something even simpler, 433MHz RF modules work well for basic data transmission. If range isn’t an issue and you want easy setup, Bluetooth modules like HC-05 are another option.
if you just want to send some simple numeric or alphanumeric data you can use this one...
and it works like this...
easier impossible, I am using it to send outside weather data to my indoor weatherstation
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Ok lots to chew on. If I can get past my resistance of all things ESP, they certainly seem to have the market share on tiny communicators. And KM is right. Adding stuff is going against my #1 priority that it has to be small.
The nRF24L01 ones all seem to have a pretty large antenna involved. Can they be used with something smaller?
The HC-12 certainly has the ease of use thing going for it. Now that I'm looking at them; That same company has HC-5 & 6.. What sets these apart from one another?
BTW Thanks for all the input. This is helping a lot!
-jimlee
Not really a company.. Chinese general modules. HC12 is serial-RF 433MHz bridge. HC-05 is bluetooth bridge.