I finally got off my butt and made a little pcb to attach an Adafruit
Feather board directly to the back of the M100, where the db25 directly
on the board takes the place of a serial cable, and a max3232 chip and 5
caps on the board takes the place of a separate ttl-rs232 module. Any
Adafruit Feather board could be plugged in, but for starters, only the
TX/RX pins are connected, and it's mostly just good for running PDDuino
on either of the two versions of Adalogger boards. There is an Adalogger
board based on a 32u4, and one based on a M0. Even the 32u4 works fine
for just doing TPDD.
https://github.com/bkw777/PDDuino/tree/master/PCB
Which fits either of these,
https://learn.adafruit.com/adafruit-feather-32u4-adalogger
https://learn.adafruit.com/adafruit-feather-m0-adalogger
Not Yet Tested, do not order. I have already ordered everything to test.
The layout also works on T102 even though the T102 and Olivetti M10
serial port is upside down.
The Adalogger boards have a built-in lipo battery manager, so I included
a power switch which uses the "En" enable pin which disables the voltage
regulator. The digikey BOM includes a neat little lipo cell that plugs
in to the JST connector and tucks in the space created between the
Adalogger board and this adapter board.
The battery is totally optional. You don't need a battery because you
can run just fine off the BCR port. But, one thing I want to do is use a
wand to read the UPC codes on all my laserdiscs, so, even if you build a
BCR power adapter you still sometimes need to run on other power. And if
you have a battery plugged in, it's annoying to unplug that tiny JST
plug, so you want the power switch so you can just leave the battery
connected all the time.
You don't really need the socket headers either. The Adalogger comes
with a set of male pins, and the shoulder is taller than the components
in the middle of the adapter. You could solder the Adalogger right to
the adapter.
The aim here is mostly just low hanging fruit. This should be easier to
build than those amazing microtpdd / nanotpdd boards, and, the source is
available for this, both the kicad schematic & pcb files, and the
SD2TPDD code to run on the arduino. You just buy the off-the-shelf
Adalogger board which has all the complicated bits already done, and the
adapter board just has a few larger simple parts to install that you can
do with an iron.
Next the same thing for Teensy. Teensy now has 3 boards with sd card
reader built in. 3.5, 3.6 and 4.1. The 3.5 is interesting because it's
5v tolerant.
--
bkw
On 8/13/20 8:36 AM, Brian K. White wrote:
On 8/12/20 10:46 PM, RETRO Innovations wrote:
On 8/12/2020 9:30 PM, Tom Wilson wrote:
Maybe we can build a new NADS using Arduino? A Teensy with built in
SD socket is fairly inexpensive; we would just need a level
converter and to port the program to Arduino platform.
Is the program open sourced somewhere?
Alternatively, is there some available C code for this functionality?
Jim
Jimmy Petit wrote an arduino implementation.
I added a little to that.
I have it running on a few different boards that have an sd card
reader built in.
http://tandy.wiki/PDDuino
https://github.com/bkw777/PDDuino
Just the other day I found a cheaper & simpler ttl-rs232 module
instead of the Schmart one in that video.
With this one, it's already got a male plug, and is wired DTE, so you
just use the same cable that you use to connect a M100 to a PC, and
powered with a short usb cable and a BCR-USB adapter.
Links to all those items in the readme on github.
I want to see if it'll work on an OpenLog board, which is way tinier,
yet still has a microcontroller, rs232(ttl), and sdcard reader, which
is about all you need for a TPDD.
https://www.aliexpress.com/wholesale?SearchText=OpenLog&SortType=price_asc
Amazon & ebay etc have them too.
Though with that, I think you probably have to provide 3.3v power,
while the adalogger/teensy boards have usb inputs and on-board
regulators. Adalogger even has it's own lipo manager built-in too,
though, this code is drawing so little current that the BCR port is
fine and you don't have to worry about any batteries. (2-3ma when
idle, 20ma briefly just while actively reading or writing)
Next step is get rid of the ttl-rs232 module and cable, and make a pcb
with a 25 pin plug and the max3232 & caps, and the adalogger or
teensy, and get power from the bcr port with the usb adapter.
There is a now a new Teensy 4.1 which has a sd card reader to add to
the list, but it's pretty ridiculous overkill for this. Teensy 3.5 is
already overkill. I haven't ordered a 4.1 yet, and so the code doesn't
support it explicitly yet, though I'm sure it requires almost nothing
to do so. I'm more interested in going the other way and try to use
one of those OpenLog boards.
--
bkw
