Serial Communication question

jmbertoncelli@USA

Hello

What is the maximum serial speed that we can achieve using the Prop?

Thanks.

jm

Timmoore

There is a lot of different serial protocols, so I am going to assume you mean async serial ports. It still depends on whether you mean burst or sustained and if sustained how long? The Fullduplexserial driver people have had it working up to around 700-800kbps. I have seen other threads where people have written other drivers that go faster. The fullduplexserial receives into a buffer so sustained depends on whether the processing that is taking the data is fast enough before the receive buffer overflows. If you 'own' both ends of the link you dont have to use async serial and can go faster.
You probably need to explain a bit more about what you are trying to do to get some options.

jmbertoncelli@USA

Thanks for your answer!

In fact I am building a Prop object for an XBee pro RF modem and I am currently testing the different speed. So far using the fullduplexserial I was able to achieve 38400Kbs. Do you think that it is possible to acheive higher speed?

I tried 57600Kb but when using this value the comminucation does not start at all?

jm.

Timmoore

I have run fullduplexserial at 115200 with a number of devices though I normally use my own driver now.
I have used a xbee but I dont think it was the pro. Looking back at the code looks like I had it running at 115200 but I remember connecting the xbees to a PC and re-configuring them using the x-ctu tool

jmbertoncelli@USA

This is exactly what I am doing right now but I was not successful with the Prop only at 38400Kbs. IF you were able to transmit from the prop at 115200 then what was your _clkmode and _xinfreq ?


my test program:

CON
_clkmode = XTAL1 + PLL16X
_xinfreq = 5_000_000

OBJ
Link : "FullDuplexSerial"

VAR
byte buffer[noparse][[/noparse]1024]
word count

PUB Main
Link.Start(1,0,0,38400)
ByteFill(@buffer,0,1024)
buffer := string("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")

repeat while(1)
Link.str(string("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"))
Link.str(string(" "))
Link.Dec(count++)
link.tx(13)
link.tx(10)
Return

jmbertoncelli@USA

I mean that I was successful up to 38400Kbs

Timmoore

Can X-ctu talk to the Xbee @ 115200? That would be a good test, if that works then try the prop.
I would have been either working with a 5Mhz or 6Mhz crystal, probably 5Mhz the same as you.