Best way to transfer fast data over 1 meter cable

[ISeed]

Hello, all!

A quick question: if I want to transfer data between 2 STM32 devices, which are located 1 meter apart, at a rate of at least 20Mb/s, in bursts of 300KB at a time. what is the best way to do so?

The communication is unidirectional.

I suppose my options are either :

• SPI (which I'm not sure about, because I understand it's only good for up to ~30 cm)
• 8 parallel data lines with a clock, which allow me to effectively cut the bit rate by 8, but I don't know if it will actually be reliable and if suitable cables with enough wires are available for purchase.
• Some other possibility I'm not thinking about?

Thanks!

[AvaTar]

> I suppose my options are either :

• SPI (which I'm not sure about, because I understand it's only good for up to ~30 cm)

With proper drivers (I mean hardware) and homogenous, impedance-matching cables, this works.

I had been on a project that successfully used SPI over ethernet patch cable as means of communications.

A higher level protocol to detect and correct transmission corruptions is advised, though.

[After Forever]

This might help - Extending the SPI bus for long-distance communication

[ISeed]

Thanks! reading now

[ISeed]

Thanks! These drivers, are they independent HW components I can look for, at, let's say, DigiKey? How are they called?

Do some STMs happen to have those on board?

[Tesla DeLorean]

Ethernet

One could likely fake a version without magnetics for point to point.​

[AvaTar]

> These drivers, are they independent HW components I can look for, at, let's say, DigiKey?

Yes, so much I remember. But not a specific name, it was more then 6 years ago.

In general bus drivers with an output impedance matching that of your cable. Ethernet cable and RJ45 connectors are a relatively cheap solution.

Perhaps differential drivers for RS485, CAN, or similar. The transceiver chips are usual not specific for said protocols, only the bus levels. Bandwidth should be sufficient, I would say about 100MHz for a digital 20MHz signal.

Or asymmetric one's, like 74 series bus transceivers.

[S.Ma]

Ethernet is good.

Backup would be monodir link

Check on DS90LV031A cmos to lvds to cmos

[Uwe Bonnes]

20MB/s and 100 Mb Ethernet does not fit together. 20 MB/s is > 160 Mb/s.

Does the llink need to be bi-directional? Does the link need to be flexible with a cable or can it be a backplane. Maybe some serdes chip connected to the FMC can do the job.

Otherwise STM32MP1 has Gigabit Ethernet.

[AvaTar]

I think this is an ambiguity in the OP.

SPI would not be able to manage 20MByte/s, neither would the receiver really be able to sustain this data rate for sensible package sizes.

I suppose he meant 20MBit/s.