PX41CX extra characters on terminal connection

[krischik]

When DUMPin the calculator content I get all sorts of extra characters:

Code:


>Miniterm.command                                          
--- forcing DTR active
--- forcing RTS active
--- Miniterm on /dev/tty.usbserial-1430  115200,8,N,1 ---
--- Quit: Ctrl+E | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
KÛÛ[ÛkÛI[$ÿÿim{ÛoÛ¶oÛ}Ú[ÛkÛ[û␡ßm{ÛoÛ_ûÿÛÛKÛiÛ¶ßÛmm{ÛoÛ_ûmÛÛ{ÛoÛÿýÛÿû[ÿûÿßkÛIÛÛ-}Ûß[ÛkÛI¶ûÛÿÛ{ÛoÛùûkÒ{ÛKÛÛûÛ␡ûÿÛmÛÛÛÛÛÿÚKÛi[[ûiÿ{ÛoÛÛÛ␡ÛïÒÛ{ÛKmÿßý[ÛkÛI[û_û[ÛkÛÒÛ[ÿÛIÛÛ{»ÊÛKßkÛmÛû·Ûÿï{ÛkÛmÛK␡ßÛÛ{ÛoÛÛÛÿû÷ݵ¯5½¥­Õ½µÝ­µµµµµU½µÝ­¯­µ­µ×µµÍ­·­µ­µ×µµ​͵¯µµµµWµ­ý­µ­µ­­Õ­µUµ½µ­½µÕ­µUµ×µµµ½×­­}ÿÿïÿÿÝÿÿÿÿÿÿÿïõµU½µÍ­¯µµµµWµ­ý­­­µ½µÕ­µ​Uµ½µ­½µÕ­µUµ¿µµÕµWµ­õ­­µµ­µÕµµUµ­µ­½­Õ½µÍ­¯µµ­µWµ½õ­­µµý␡ÿÿ¿¿ýÿÿÿÿ␌
PX41
04 01620000000002 00000000000000 00000000000000 00000000000000 
08 4b039200000000 90fffffffff0ff 00000000083000 00000000000000 
0c 1000000000019c 1a70016919c19b 0000002d048000 00000000007000 
198 00000000000000 00000000000000 00000000000000 00000000c00020 
A: 09999999999000  B: 0000002d0480fd  C: 000000002d00fd
S: 00001010000000
M: 000018a5ff83d3  N: 000000000000c0  G: 00
EOF
␄ÿµõ½U½µÝ­­µµµ½Õ­µÍ­¯µµ­µWµ½õ­­­µ­µÕµµUµ­½½µ­Õ½µÝ­­µµµ½×­­uµ½µÕõµU­µÝµ­µµµ½Õ­­Ý­​¯­÷ëÿû¯ÿÿÿÿWõ­­­µ½µÕµµU½¯­­½µ×µ­Í­¯µµµµWµ­ý½­­µ­µÕ­µÝµ­µµ¥½Õ­µUµ¯½­½­×­­Ý½¯­µ­µ×​µµÍµ¯µµµµW½µÿ¿ÿÿïÿ¿ÿÿÿÿV5µ¥½Õ­µÝµ­µµµ½Õ­­Ý­¯­µ­µ×µ­Ý­¯µµ­µ×µµÍ­¯µµµµWµõõ­­µµ­µWµ​½Õ­­µµµµW½µý­­­µ­µÕ­µUµ½µ­½µÕ­µÝµ­µµµ½×­­uµ­½õ¥­Õ­µÝ­ÿ¿ÿûÿúµÛÿï[ÛkÛI␥m␡␡Û[kÛmÛÚ{{ÿÛ{Ûo␥i␡ûomÛÛ{Û·ÛûÿÛ{Ûo[ÚïÿÿÛ{Ûo[I␡{ÛÚ{Ûo[Ò_[ûJÛÛ[Û%ÛÛkÛm[ÛoûÞßÿþKÛi[Ûm␡ÖÛkÛmÛÛßûÿÛ)ÚkÛÛm␡–ÛkÛmÛÛkÿ␡Û)ÚkÛÛ[ÛûnkÛmÛÛiÿ␡ûÛIÛÛ{ÛÿòÒoÛI[Ûë

That doesn't look good. Is this this a problem with the calculator build, a floating data line, leakage currents or just normal?

I use macOS and get the problem with any terminal emulation. Parameters used for Miniterm where:

Code:


python3 ${Python_Packages}/serial/tools/miniterm.py \
    --echo                        \
    --encoding "Latin1"                    \
    --eol "LF"                        \
    --rts 1                        \
    --dtr 1                        \
    --rtscts                        \
    --exit-char    "5"                    \
    --menu-char    "20"                    \
    "${USB_Serial_Device}"                \
    "${USB_Serial_Speed}"

Full source code: Miniterm.command

[Pierre]

The "noises" problem is mentioned in my manual (page 30).
It seems to be less noticeable when the port speed is 115200 baud.
I use CoolTerm (on Windows) because Alex recommended it (he uses it on Mac!)
And my transfers work perfectly in both directions.

(I only use python for firmware updates)

[agarza]

(08-31-2024 06:08 AM)krischik Wrote:  When DUMPin the calculator content I get all sorts of extra characters:

The PX-41CX shares the SPI (Display) and UART (Serial data) ports due to the limited number of pins on the AVR128DA.

The noise you’re seeing is actually the data being sent to the display.

When dumping the PX-41CX memory, an FF character is transmitted at the start, and an EOT character at the end of transmission.
This helps reduce noise, as CoolTerm allows you to set these characters as filters. In CoolTerm, configure FF (Clear on Form Feed) and EOT (Update the Display on End of Text) in the Data Handling section.

Hope I made sense.

[krischik]

(08-31-2024 01:39 PM)agarza Wrote:  The noise you’re seeing is actually the data being sent to the display.

That is ok then. I can work around that.