Forums

TX <--> TX. Did it again

Started by Tim Wescott June 30, 2015
Argh.  So, I think I manage to get the UART outie hooked up to the USB 
and/or RS232 converter outie (and innie to innie) well over half the time.

And, I just did it again.  The STM32F303 has a SWAP bit in its UART 
configuration, to swap the TX and RX pins, but that would be cheating 
(and besides, I did it with RTS/CTS as well).

C'mon.  Say that _you_ get it right all the time!

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
On 6/30/2015 2:17 PM, Tim Wescott wrote:
> Argh. So, I think I manage to get the UART outie hooked up to the USB > and/or RS232 converter outie (and innie to innie) well over half the time. > > And, I just did it again. The STM32F303 has a SWAP bit in its UART > configuration, to swap the TX and RX pins, but that would be cheating > (and besides, I did it with RTS/CTS as well). > > C'mon. Say that _you_ get it right all the time!
I pin connectors (male/female) as DCE/DTE, accordingly. Then, whenever I want to mate two connectors, I simply look at the gender: if complementary, they will mate 1:1; if the same, then I need a "gender swapper" (that swaps the outs and ins, accordingly -- so the new, "effective" connector is now complementary to the mating one) [I have a box of these "widgets" that adapt "X" to "Y" -- for a variety of X and Y] Life is too short to fuss with pinouts! :>
On Wed, 01 Jul 2015 07:17:08 +1000, Tim Wescott  
<seemywebsite@myfooter.really> wrote:

> Argh. So, I think I manage to get the UART outie hooked up to the USB > and/or RS232 converter outie (and innie to innie) well over half the > time. > > And, I just did it again. The STM32F303 has a SWAP bit in its UART > configuration, to swap the TX and RX pins, but that would be cheating > (and besides, I did it with RTS/CTS as well). > > C'mon. Say that _you_ get it right all the time! >
I used to get it right all the time. I had a port monitor/configure thingy - I just kept flipping switches until I got the maximum number of lit leds and whoosh went the data. Checking the switches then told me how to wire up a permanent cable. One of the best bits of kit possible for RS232 and about $10!
On Tue, 30 Jun 2015 14:26:05 -0700, Don Y wrote:

> On 6/30/2015 2:17 PM, Tim Wescott wrote: >> Argh. So, I think I manage to get the UART outie hooked up to the USB >> and/or RS232 converter outie (and innie to innie) well over half the >> time. >> >> And, I just did it again. The STM32F303 has a SWAP bit in its UART >> configuration, to swap the TX and RX pins, but that would be cheating >> (and besides, I did it with RTS/CTS as well). >> >> C'mon. Say that _you_ get it right all the time! > > I pin connectors (male/female) as DCE/DTE, accordingly. Then, whenever > I want to mate two connectors, I simply look at the gender: if > complementary, > they will mate 1:1; if the same, then I need a "gender swapper" (that > swaps the outs and ins, accordingly -- so the new, "effective" connector > is now complementary to the mating one) > > [I have a box of these "widgets" that adapt "X" to "Y" -- for a variety > of X and Y] > > Life is too short to fuss with pinouts! :>
This is on a board. Chip out to chip out, chip in to chip in. Cut traces and little blue wires now abound. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
On Tue, 30 Jun 2015 16:17:08 -0500, Tim Wescott
<seemywebsite@myfooter.really> wrote:

>Argh. So, I think I manage to get the UART outie hooked up to the USB >and/or RS232 converter outie (and innie to innie) well over half the time. > >And, I just did it again. The STM32F303 has a SWAP bit in its UART >configuration, to swap the TX and RX pins, but that would be cheating >(and besides, I did it with RTS/CTS as well). > >C'mon. Say that _you_ get it right all the time!
I sometimes use different words, like POLL and REPLY, to avoid the tx/rx ambiguity. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On Tue, 30 Jun 2015 16:17:08 -0500, Tim Wescott
<seemywebsite@myfooter.really> wrote:

>Argh. So, I think I manage to get the UART outie hooked up to the USB >and/or RS232 converter outie (and innie to innie) well over half the time. > >And, I just did it again. The STM32F303 has a SWAP bit in its UART >configuration, to swap the TX and RX pins, but that would be cheating >(and besides, I did it with RTS/CTS as well). > >C'mon. Say that _you_ get it right all the time!
Yes. I just refer to the Annabooks PC handbook. Cheers
On 6/30/2015 3:55 PM, Tim Wescott wrote:
> On Tue, 30 Jun 2015 14:26:05 -0700, Don Y wrote: > >> On 6/30/2015 2:17 PM, Tim Wescott wrote: >>> Argh. So, I think I manage to get the UART outie hooked up to the USB >>> and/or RS232 converter outie (and innie to innie) well over half the >>> time. >>> >>> And, I just did it again. The STM32F303 has a SWAP bit in its UART >>> configuration, to swap the TX and RX pins, but that would be cheating >>> (and besides, I did it with RTS/CTS as well). >>> >>> C'mon. Say that _you_ get it right all the time! >> >> I pin connectors (male/female) as DCE/DTE, accordingly. Then, whenever >> I want to mate two connectors, I simply look at the gender: if >> complementary, >> they will mate 1:1; if the same, then I need a "gender swapper" (that >> swaps the outs and ins, accordingly -- so the new, "effective" connector >> is now complementary to the mating one) >> >> [I have a box of these "widgets" that adapt "X" to "Y" -- for a variety >> of X and Y] >> >> Life is too short to fuss with pinouts! :> > > This is on a board. Chip out to chip out, chip in to chip in. Cut > traces and little blue wires now abound.
Ah, well... you're stuck, then -- unless it was a trivial component whose schematic symbol was misrepresented. Nowadays, with pins having a multitude of optional uses, you can't realistically draw each chip with the "right" pin orientation (gazintas and cumzoutas). There's a reason we have Xacto knives with *tiny* points! :>
On Tue, 30 Jun 2015 16:17:08 -0500, Tim Wescott
<seemywebsite@myfooter.really> wrote:

>Argh. So, I think I manage to get the UART outie hooked up to the USB >and/or RS232 converter outie (and innie to innie) well over half the time. > >And, I just did it again. The STM32F303 has a SWAP bit in its UART >configuration, to swap the TX and RX pins, but that would be cheating >(and besides, I did it with RTS/CTS as well). > >C'mon. Say that _you_ get it right all the time!
I get it right every time. My naming convention makes it pretty easy to keep them straight. What I fuck up is I2C clocks and data. I don't know why but it happens *way* too often. That, and forgetting the pullups. They usually don't find it in design reviews, either.
On 6/30/2015 5:17 PM, Tim Wescott wrote:
> Argh. So, I think I manage to get the UART outie hooked up to the USB > and/or RS232 converter outie (and innie to innie) well over half the time. > > And, I just did it again. The STM32F303 has a SWAP bit in its UART > configuration, to swap the TX and RX pins, but that would be cheating > (and besides, I did it with RTS/CTS as well). > > C'mon. Say that _you_ get it right all the time!
I was in a design review meeting once where people were getting a bit confused about what was in and out at the board/chip level and what was xmt/rcv at the system level. In the end they decided to use names for the system level. One guy was so confused by the whole thing that he was trying to suggest that every such signal should have two names since each signal was an input on one end and and output on the other. lol Then shortly after that I ran into an actual description of SPI and found signals labeled MOSI and MISO. Can't get any more clear than that unless you don't know your master from your slave! -- Rick
Tim Wescott:
> Argh. So, I think I manage to get the UART outie hooked up to the USB
> and/or RS232 converter outie (and innie to innie) well over half the
time.
> > And, I just did it again. The STM32F303 has a SWAP bit in its UART > configuration, to swap the TX and RX pins, but that would be cheating
> (and besides, I did it with RTS/CTS as well). > > C'mon. Say that _you_ get it right all the time! > > -- > > Tim Wescott > Wescott Design Services > http://www.wescottdesign.com
I get it right every time (of course) but make up for it my mixing up genders of D connectors so you have to solder them to the other side of the PCB. I do get into problems when interfacing with other boards - my TX is TX but they think that their TX is as well ! I once worked a lot with an engineer (he was the boss) who reckoned that the odds of getting it right were so little improved by thinking about it that it was a waste of effort since it took so little time to cross the wires in the cable. (They made bespoke production lines.) Michael Kellett