Hi,
The second post gives at least a bit of technical informations.
Hopefully it´s not asking too much for a simple sketch with complete informations (drawing and text).
So it´s not very clear "what" and "why".
Correct me if I´m wrong. But you want a data communication via a 3.3V DC power line.
If so:
* Why no third/fourth wire for data?
* why not RF or optical (IR)?
* why UART? why not modem style ... or other solutions? (like DTMF...)
If you want to stick on a 2 wire solution: (3.3V power supply plus data)
* what about baud rate? continous, or data packets?
* what information do you send/receive?
* one way, or both directions?
* only one master/transmitter?
* only one slave/receiver?
* if one way: is the data direction the same as the power direction?
* small PCB: at Tx at Rx or both?
For sure any additional information about your application is helpful to find the best solution.
For example:
You will need different solutions depending on load (power). A power line data tarnsfer is more simple for
* an always ON incandescent light
* than a PWM´d DC motor
(from the view of noise, currents, voltage levels, margins...)
Klaus
I'll try and answer as best as I can...
Uart because thats what I have available. The master micro has this spare. But also the current design and program uses it. Changing to another data system would be an extra pain to deal with.
no extra wires because currently its all going through a custom hinge assembly. Which is proving to be a nightmare to make. While doable a huge amount of work is going into it and its becoming a problem.
So going through a solid hinge for power and data would be better in this project.
RF might be ok if its simple and low powered enough. But im not an RF engineer.
No IR, while doable as the two chassis do meet. It would break the aesthetic design.
Not heard of DTMF tbh.
I can only use two wires... Power and GND. Hence going through two hinges.
Baud rate, as high as reasonably possible tbh. 112k would be fine. 1M would be nicer...
Data is sent in burst packets roughly every 5ms. Mostly just relaying between two micros a main one and secondary one. Main one sends out mostly LED data to the secondary. And the secondary sends button state data back. Give or take some error correcting resends.
Id like this to be two way data.
And yes a small PCB. I'm happy working with 0603s or 0402s and extremely dense pcb designs.
Currently the foot print for the PCB could fit about 10mm by (at a max) 30mm.