Post Reply 
New Project wp34s micro usb flash cable revisited
02-08-2015, 02:04 PM (This post was last modified: 02-08-2015 02:08 PM by MarkHaysHarris777.)
Post: #21
RE: New Project wp34s micro usb flash cable revisited
(02-08-2015 06:59 AM)matthiaspaul Wrote:  If you have opened the converter already, you might check if the RTS/CTS pins (and in case of the FT232RL or PT2303HX also the DTR/DSR/DCD pins) are connected with each other or not. If they are still open (that is, not connected to anything else), you could short them. With this patch in place, it is no longer necessary to disable hardware handshake when opening serial connections through USB - it will work both ways. While this isn't normally a problem when using dedicated software it'll make things easier when setting up a connection in a terminal program.

BTW. Based on a photo of Harald's USB board, he didn't connect RTS and CTS as well, so this patch also applies to his board.

PS. Where do the 5.1V and 3.4V figures come from? Shouldn't this read 5.0V and 3.3V?

hi Paul, nice to meet you... I have never actually looked closely enough at the PL2303HX pinouts on *any* of these boards / I have not had any difficulty using terminal, usually minicom on gnu/linux, but then I configure things as a null modem and disable all the hardware negotiating. I can tell you that the board I'm using is 'flaky,' by that I mean it does not work with MySamba 100%. ... about 80/20. If I retry it will work. I don't know whether its the timing in Marcus' stuff; but I suspect that the unit needs to be in the right state (115200,N,8,1) or it won't work. I open up terminal and make the settings, then close terminal without reset.... seems to be more reliable; but its not 100%. I'll take a look at the pinouts on the PL2303HX and let you know. Interesting.

I didn't think Harald's board had any advantage (but I was wrong). I thought it was bass-ackwards until I realized that the board ALSO has the IR driver circuit on it... solder the IRD directly to his board which has the driver transistor and current limiter. He actually did a very nice job with that thing. But, I still don't really like the physical mod/ oh well.

The voltage levels on my board are called 5.0 and 3.3; however, they measure at 5.1v and 3.4v / both depend on the regulators in the PC of course, but the 3.4v on the board is being regulated on-board, and its fairly robust. I have to admit that in the process of experimenting with my flash-box I had a solder bridge on the 3v side (nothing worked and the adapter plug got VERY hot ) I figured I toasted it. NOT SO; saved just in time. It was not damaged, which means there is overload protection built into that thing as well. Its an impressive little board as well.

I was thinking of disassembling the board (mounting the board inside the 34s, and wiring my own micro usb connector female side in the backplate under the battery cover. Calculator won't lay flat, but I don't really care... I have to hold it anyway to press the control buttons for update on the front and still be able to get to the reset hole in the back (I won't be laying it flat). The way I'm thinking about it will keep the connector clean. On the other hand, Barry's idea is just so dang simple, its hard to resist (three wires and one phone jack).


Kind regards,
Find all posts by this user
Quote this message in a reply
Post Reply 

Messages In This Thread
RE: New Project wp34s micro usb flash cable revisited - MarkHaysHarris777 - 02-08-2015 02:04 PM

User(s) browsing this thread: 1 Guest(s)