can many devices, share ONE arduino serial outpout??

Projects General Guidance
1

hello forum. my question is prety much, what the tittle says... what i eaxctly want to do, is something like that :

have an arduino(1) read some sensors, and calculate some numbers. then convert them to a serial string, and outpout it, via the digital pins, 0 and 1..
on the other side, i want to have

  1. another arduino(2), to read that serial directly from the arduino(1)'s output pins.
    2)a Bluetooth module, that connects to the arduino(1)'s output pins and the connects to a pc.
    3)a TTL to usb converter, wich then connects to enother pc...

is this ale to be done at all? or am i just flying in clouds? :stuck_out_tongue:

2

Physically you can do this. However, you will get all the gumf that bolo tooth needs sent to the other devices. While many devices can pick up a serial output from the arduino, Only one device can be wired to talk back to the arduino.

3

And if you have several devices connected to the same output pin it might be a good idea to have a buffer chip in between - such as a 74HC4050 according to my 1996 book.

...R

4

sorry my bad. i forgot to mention, i do not want any of the devices to talk back to the arduino(1) . they all just need to hear!!

robin2. can you explain me what you sed about the buffer chip?? (And is it neccecery, in the light, that i dont need dublex comunication? )

5

The purpose of the buffer chip is just to increase the output power so that all the listeners get a good signal.

I don't know if it's essential in your situation. I haven't noticed any details of how many TTL loads an Arduino pin can supply.

...R

6

Arduino can suppluy 20mA, which is a lot of CMOS inputs. I have driven 20 shift registers over 2 boards with no problem.

7

One could also daisychain the Arduinos, ie the TX of Arduino#1 goes to RX of Arduino#2, the TX of #2 goes to RX of #3 ... Of course the code needs to replicate the character.

And if you close the loop with the last Arduino connected to the first, then you have reinvented the Token Ring :slight_smile: ((Sounds like a nice project, for those that like to write protocol software.- but I digress))

8

cool. thanks allot everyone for the replies!!!