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Why I made FTDI_232 DIY ugly USB>serial (long story). — Parallax Forums

Why I made FTDI_232 DIY ugly USB>serial (long story).

Why ?

It's very simple. I needed a way of flashing @"Peter Jakacki" 's excellent Tachyon Forth into my ugly P1 dev board I built (see this thread for details P1 DIY minimal dev board - a weekend project (completed)., or maybe not). As it is often the case with my activities, I usually find myself ill prepared. It turned out my cheap, CH340G based usb>uart wasn't up to the task. It works fine and I was even able to load my ugly P1 dev board with some simple demo programs but somehow it wouldn't load Tachyon. This seemed a bit strange and while not a hardware issue with any of my boards, it still needed to be solved. Having neither time nor the skills to debug whatever software issue might've caused this situation, I turned to this very forum for help. Then @Wuerfel_21 stepped in and suggested the cause and the possible resolution (see these links for details The bug is quite old - most recent activity is that it is supposed to have been fixed 2 months ago..., and the solution https://github.com/parallaxinc/PropLoader ). While it seemed to be the solution to my issue, and a nice one at that, I recalled something funny that @Mickster has in his footer and decided not to pursue that path :). I was left with either buying a suitable usb>uart converter (based on FT231x(newer) or FT232r(older)chips as these are the parts used in the Prop Plug and supported by the Prop Tool) or making one myself. I like things simple and easy, if possible, so the "buy" option is always on top of my list. I searched at Mousers' and Farnells' sites for a ready made board. The cheapest I found was just under $8. Not bad but I couldn't wait until next week so I searched through my junk and found a good candidate - a FT232RL on some wasted board from 2009 (I have no idea what that board was intended for but it sure looked very pro). Initially, I thought of cutting the complete usb>uart interface out of the board but it turned out to be impossible with whatever tool I had as this was a multi-layer, more than 3mm thick, very high quality board. I ended up de-soldering the parts with my old transformer soldering gun. Not a trivial task, I must admit, so the FT232 chip suffered a missing D+ pin. I'm too stupid to know when to give up so I proceeded with soldering the chip on an universal 28 pin TSSOP adapter board with the rest of the salvaged components, fixed that missing pin with a tiny piece of wire then added the mini usb socket. When I was done with soldering all of the parts I connected the board to my Lenovo x200s win7 laptop and ....it started installing the driver for the chip. That was a good sign. When done with the driver installation, I hooked up my ugly P1 dev board to this newly made, also very ugly, usb>uart converter, fired up a Prop Tool, double checked the port configuration and tried to load the Tachyon binary. It loaded flawlessly this time. The EEPROM also loaded without any problems.
Success !
The short version of this you can find here FTDI_232 DIY ugly USB>serial (5 hour project).

And two questions for you, if you care to answer:

1. Was it worth building (would you consider doing such a thing ) ?
2. Was it worth reading about this little project ?

Comments

  • Yes to both!
    Thanks for sharing!
  • I am totally humbled. Totally blown away with the soldering iron as I am the proud owner of the TS80.
    Everything I do now, isn't as seif-satisfying as it used to be :lol:
  • These TS80 are very nice. I envy you. I once contemplated buying it but whenever I visit their site they are sold out. Besides, for hobby projects I couldn't justify the expense.
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