Data logger for printer

Hi Parallax Forum,
I am looking to develop a data logger module to log data off of a custom 8-pin printer port to a SD card ASCII text file. Really simple text file stuff - nothing fancy. I figure the best way to tackle this is to convert the parallel byte to a serial string using an IC and then write it to the file as a serial stream.

I am comfortable with the BS2P24 stamp module and would appreciate any advice on data loggers that exist and others have used recently.



  • Have you looked at StampPlot pro or lite by
  • Hi DigitalBob,
    thank-you for the referral, however i am looking for a device that can log serial data to a text file and store that onto a SD card or USB key. I am hopeful the device can be integrated with a BS2P stamp module.

    If anyone has any IC modules that can accomplish this, please let me know. Parallax used to sell a product a few years back....

  • I think I ran the bs2 with a USB I'll check my files and post it if I did.
  • I've used the Memory Stick Datalogger (#27937) from Parallax, unfortunately it's not available anymore. Perhaps you can find a second hand though.
  • Chris
    I run the Vdrive3 from FTDI chip. And I use the code from the parallax 27937 thumb drive that I have but never could get it to work. So this is my version of the 27937 code with some minor tweeks. It runs great with the Vdrive3.

  • This is for the BS2 I don't have a BS2P to try it on.
  • Tracy AllenTracy Allen Posts: 6,421
    edited 2018-04-26 - 19:31:08
    Chris, how much data will you printer port logger need to store, and how fast?

    I can confirm that the VDRIVE3 works with a BS2pe. I've used it for deployed systems and like Bob I'm sure I've made tweaks along the way. The VDRIVE is very picky about certain things, but reliable once you get those nailed down. It got kind of complicated in my apps, and the VDRIVE code moved to its own slot, accessed with cross-slot calls. It handles a bunch of tasks that you might not need in your application, if you simply need to write the strings. I'll attach the VDRIVE slot object for reference. This example was fine-tuned for logging data from 20 rain gages plus RH, °C and wind parameters at intervals of 20 minutes. The Stamp powered the VDRIVE down in between to conserve the battery. The slot that scans the sensors stores the data in binary in the scratchpad RAM, and then calls the VDRIVE slot, which expands it out to a fixed length ascii string to write to the flash stick.

  • Hi Tracy and DigitalBob,
    thanks very much for the feedback and referrals. My intent is to trap printer data from a 8-pin dot matrix parallel printer port off of a product....I know two of the 8 pins are VDD, and i am guessing that two are something like CTS/RTS, which leads me to believe that the remaining 4 pins are upper and lower nibble. Once i get that sorted out using a terminal program, i can use the SERIN command and a shift register to get the data into the BS2P.

    From there it is simply writing the data out to a SD card or USB key using a generic file name "MM-DD-YY.txt" a pretty straight forward application....maybe add a simple keypad and LCD display...but that is Rev 2. I will power this either from the on board +5V or add a AC/DC to get +5V DC for the application. For me it is all about getting the data buffered inside the BS2P and then writing it out to the USD/SD card.

    Let me look over the VDRIVE3 documents you guys have shared to start.

    Thanks much,
  • chrisdlove,

    The Propeller microcontroller might be better suited for this task and its Spin language is very similar to PBASIC.
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