thanks for the simplified schematic and hex!!! 😀
this mind sound stupid, but why the pins of the st232cn are not in order? it is so they are easier to draw right?
It is one of two available chip outlines available in the CAD application I used. I didn't draw it myself and it also misses out the power on pins 14 and 15.
BTW, if you use an alternative to the ST232CN, which you may, check it's data sheet and ensure you use the value of capacitor it requires.
One other thing, the simplified version omits the bi-color LED, but it is still supported. You can wire it using two resistors on either the RA2/3 pair or RA6/7 pair.
I bought two the other day for this project but not as yet used either. They should be relatively easy to mount on your case if you go ahead with installing a converter internally which is a very good idea. I may even build one myself 😀
Nice work! I look forward to testing this out when I get some free time.
sklawz wrote:
The mice move to the intended destinations equally well. The point has been made already, the serial mouse has 20 samples per second when converting from PS/2. A standard PS/2 mouse uses more like 100 and a regular serial mouse 40. The difference is clear, the serial mouse has a less fluid motion.
It is impossible to send more samples down the serial interface at 1200 baud.
For the same Logitech Mouseman trackball mouse, in both serial and PS/2 formats, I am unable to discern between the tracking quality of the two. If the numbers you provided are correct, then I am unable to discern between 40 and 100 samples/sec. Visually, are you able to discern between 20 and 40 samples/sec w.r.t fluid motion?
Plan your life wisely, you'll be dead before you know it.
Nice work! I look forward to testing this out when I get some free time.
sklawz wrote:
The mice move to the intended destinations equally well. The point has been made already, the serial mouse has 20 samples per second when converting from PS/2. A standard PS/2 mouse uses more like 100 and a regular serial mouse 40. The difference is clear, the serial mouse has a less fluid motion.
It is impossible to send more samples down the serial interface at 1200 baud.
For the same Logitech Mouseman trackball mouse, in both serial and PS/2 formats, I am unable to discern between the tracking quality of the two. If the numbers you provided are correct, then I am unable to discern between 40 and 100 samples/sec. Visually, are you able to discern between 20 and 40 samples/sec w.r.t fluid motion?
To be fair, I am comparing the serial mouse with my desktop USB marble mouse which I only ever use. I never actually use a traditional mouse if I can help it.
It doesn't really perform much different from the emulated mouse in Virtualbox it you may look for a close comparison.
I am unable to compare against a real serial mouse because the only one I have is an MS SERIAL MOUSE 2.0A which appears to be malfunctioning, it may need a clean (as ever).
I have an MS X03-69944 PS/2 and serial compatible mouse and an MS X03-55560 adapter but I have not got around to testing if they work together as yet.
I have an MS X03-69944 PS/2 and serial compatible mouse and an MS X03-55560 adapter but I have not got around to testing if they work together as yet.
I can confirm that these two items are compatible. The X03-69944 is known as a "Microsoft Serial Intellimouse" when in combination with the X03-55560 PS/2 to serial adapter.
With regard to usage. WIN98SE doesn't appear to support two serial mouse concurrently, however, WINXP does and when used side by side I can say that if the genuine serial mouse scores 10 then the converter scores about 8. There isn't much difference in usage except that the genuine mouse has a ball and although the motion may be smoother due to a higher sample rate it is also less smooth due to this ball which the optical mouse doesn't have of course.
when used side by side I can say that if the genuine serial mouse scores 10 then the converter scores about 8.
From this information, it sounds like there is visually about a 20% loss in tracking quality due to the conversion. This sounds a lot better than the 50% loss expected from the reduction in sample rate (40 vs. 20 sps). I am pretty excited about these results.
For use as a stand-aslone external plug-in device, I wonder how long a 9 V battery will last? We could also use a keyboard splitter cable, like the Raritan does to tap into the keyboard's 5 V line. The internal solution is probably the best route if the user doesn't plan on moving the converter between cases often. If so, just make more of them!
Plan your life wisely, you'll be dead before you know it.
when used side by side I can say that if the genuine serial mouse scores 10 then the converter scores about 8.
From this information, it sounds like there is visually about a 20% loss in tracking quality due to the conversion. This sounds a lot better than the 50% loss expected from the reduction in sample rate (40 vs. 20 sps). I am pretty excited about these results.
Yes, it feels like a 20% loss in tracking quality but bear in mind that serial mice aren't too great to start with.
The ball and rollers on the old mouse though are really irritating (I had forgotten about the noise an old mouse makes) so a little less quality in projected desktop motion is made up for with a smoother and less noisy real desktop motion.
feipoa wrote:
For use as a stand-aslone external plug-in device, I wonder how long a 9 V battery will last? We could also use a keyboard splitter cable, like the Raritan does to tap into the keyboard's 5 V line. The internal solution is probably the best route if the user doesn't plan on moving the converter between cases often. If so, just make more of them!
The PS/2 spec. says 275ma max @ 5V. I haven't measured the current of my optical mice but I will another time. I am not keen on the battery idea since although the PIC is very low current I think the ST232 is 10ma idle.
The keyboard split or a phone charger may be easier.
Bye.
UPDATE: Here are the current measurements of my test mice.
UPDATE2: The above measurements also include approx. 6ma in use by a LED.
For 3 AA batteries in series (4.8V max), I don't think a battery solution would last more than 3 days without having some auto or manual shut down. The serial port, when used as a PSU, won't be able to provide enough current either. So it looks like we'll need to use a wall wart, keyboard power, or internal case power (e.g. floppy or direct from the PSU).
Last edited by feipoa on 2013-01-28, 18:34. Edited 1 time in total.
Plan your life wisely, you'll be dead before you know it.
Did anyone else happen to order the MAX232 from joinicmart on eBay and not receive it? It has been 1 month. He is selling two of these for only $0.99 with no shipping. http://cgi.ebay.ca/ws/220983887798
I do not care so much about the $0.99, but more about the loss of time before I can test this PS/2-to-serial converter out. The PIC microcontroller chip came a week ago. It also was ordered from China.
Plan your life wisely, you'll be dead before you know it.
That was my initial thought, but then I saw this statement on their eBay page, "We can't be responsible for uninsured packages. For insurance service (Having a tracking number), please contact us to add US $3.5 at the payment."
I've never had a tiny IC like this get caught up in Customs, but if it was selected at random, it is possible...
Has anyone else ordered parts for this converter? I'm interested in your test results.
Plan your life wisely, you'll be dead before you know it.
Usually customs select packages randomly. Here in Portugal only packages from European Union are not subject to customs control, unless the seriously suspect something is wrong. The 386 motherboard i ordered is still in customs since the 13th. It came from Ukraine.
I can handle myself with a soldering iron if it is needed but it would be nice a video tutorial with step by step instructions on how to build one of these converters. If someone makes a video tutorial it would be deeply appreciated.
sklawz, based on your decision for 100 nF caps, can I assume that you are using the MAX232A instead of the MAX232? Looking at the spec sheet, the MAX232 calls for 1 uF caps.
Plan your life wisely, you'll be dead before you know it.
sklawz, based on your decision for 100 nF caps, can I assume that you are using the MAX232A instead of the MAX232? Looking at the spec sheet, the MAX232 calls for 1 uF caps.
I used an ST232CN which requires 100n capacitors. If you use the original MAX232 that requires 1uF then make sure you get the polarity correct when using polarised capacitors.
