Segger RTT - How to increase maximun line count?

[muhkuhns]

I want to use Seggers RTT for data logging.. but after 199lines the Viewer starts to overwrite the old lines.. so that only the most recent 199 lines are displayed..

Are there by the way any other tools I can use instead of the standard one?

[muhkuhns]

Sorry I didn't answered this one by my own till now. As a work around I used telnet.

As far as I remember you don't have to do anything else one the rtt side after you have started the viewer as usual. Just install/enable telnet on your windows computer and you are good to.

Here is the script I wrote (.vbs) to automatically connect and log everything to a .txt file named with date+time:

set sh=WScript.CreateObject("WScript.Shell")
sh.run "Telnet"
WScript.Sleep 100
D = Date
T = Time
Timestamp = Year(D) & Right("0" & Month(D), 2) & Right("0" & Day(D), 2) & _
    "_" & _
    Right("0" & Hour(T), 2) & Right("0" & Minute(T), 2) & Right("0" & Second(T), 2)
sh.SendKeys "set logfile C:\Users\yourname\Dropbox\Messungen\" & Timestamp & "_Messreihe.txt"&vbcr
WScript.Sleep 500
sh.SendKeys "set logging"&vbcr
WScript.Sleep 500
sh.SendKeys "open localhost 19021"&vbcr
Wscript.Sleep 1000

[Lück]

Thanks for the answer. The hint to start the RTT viewer and then use any Telnet client works fine to logg the data (I use putty: Host Name = localhost, Port = 19021). However RTT does not be as fast as claimed on the SEGGER webpage. With UART printf I still get the better performance! Actually I have no idea why RTT performs bad...

[muhkuhns]

Glad and sad to hear as well. I used SEGGER_RTT_printf(0, "\r\n%d;%d;%d;%d;%d;%d;%d;%d",d...) to output my measurements every 250ms. This worked fine and the SoC could perform as usual. Sadly I can't anymore on this topic. Good Luck!

[Lück]

Thanks for your fast answers! I use SEGGER_RTT_printf(0, "%c\t%u\r\n", <uint8_t>, <uint32_t>); directly in the ISR which will be triggered 4x every 1ms. Sure, this is quite often but only few data are printed hence RTT should do the job within a few microseconds [us]. Seems that the printf overhead is quite large...

To solve this issue I will implement a large FIFO storing the received data during the test and after the test is stopped printing the whole FIFO content which is not time critical anymore.