I’ve got a load of old logitech serial mouse in the hope to make encoders from. As I understand the internal electronics of the mouse are not used and only the LED and optical detector are needed…
The LED has 3 pins (looks like 2 are connected to gnd on the board I think) and the optical detector has 4 pins - see attached pic, I hope u can see the routing of the parts on the board as to make sense of it…
So what pins of the optical detector do I connect to the DIN module?
The green and the light-blue pin is connected with the IC, so I think that these are the signals which have to be connected to the DIN module.
The red and blue are for the power supply. Here I’m not sure if a special voltage level is required. However, just plug the mouse into the RS232 or PS/2 socket of your PC and measure the voltage between these two pins.
yes, the +5V should be enough. Be carefull with the voltages, a too high level can kill the components!
The easiest and most secure way to setup the connections is the following: at first let the LED sender and receiver attached, connect the RS232 cable with your PC. Connect the ground of the mouse (RS232 pin #5) with Vss of the DIN module, and the green and light-blue pin of the receiver via two resistors (*) to the DIN inputs. Now the MB16E firmware should regognize movements of the mouse and send out MIDI events. Thereafter measure the voltage levels of the sender and receiver during operation - they could be different now. If they are still about 5V or higher, the components can be supplied with Vdd of the DIN module without additional measures. If they are lower, you probably need series resistors - measure the current which is going through the components and calculate the required resistances with following formula: R = (5V-V_measured) / I_measured; Example: R = (5V - 2V) / 15mA = 200
Take the next higher available resistor from the E12 table (100, 220, 330, 470, …): 220 Ohm
More details can be found in any book about electronics (-> ohms law)
Best Regards, Thorsten.
(*) the resistors protect the 74HC595 from too high currents between the two voltage domains (RS232/MIDIbox). Values between 100 - 1k are ok
Great, thanks again T - cleared up things nice, tho i’ll prolly have a few more q’s when it comes to testing (still gotta get parts and make the modules)…
However, these encoders are coming on nice i’ve reused most of the mouse and created an endless pot with an intergrated switch (the mouse switch) housed with a half cut of the rubber cover from the ball, so it acts like a pushswitch - looks nifty, weather it works or not is another thing ;). I’ll get some pics up soon…
I was thinking of doing a walkthrough - but it’d take a while, plus u’d have to get the same type of logitech mice I used - tho I’m sure a general guide would be a good idea as most old serial mice have similar asthetics…
In the meantime, here are a few pics of one of the encoders (i made 8 in total). The mouse switch has been reused and is placed in the rubber housing (used the old mouse ball ). It works really well so far, but as stated there’s still a lot to do ;)…
The encoder wheels I made (not pictured) have 36 spikes and are made from black CD jewel cases…
I was also thinking of intergrating an LED in the button too (it lights up the rubber cap real nice when lighted from beneath), but the LED rings will be enuff I think
The easiest and most secure way to setup the connections is the following: at first let the LED sender and receiver attached, connect the RS232 cable with your PC. Connect the ground of the mouse (RS232 pin #5) with Vss of the DIN module, and the green and light-blue pin of the receiver via two resistors (*) to the DIN inputs. Now the MB16E firmware should regognize movements of the mouse and send out MIDI events.
Done that but just connected the green and light blue pin of the rcvr straight to the DIN module which had the 10K resistors there already. Moved the mouse and low and behold there was MIDI!! When i moved the mouse left i got ‘B0 13 3F’ msgs and when moved right i got ‘B0 13 41’ msgs (tho a B0 13 42/3 popped up occasionally too)
I measured the V of the Receiver (if thats the one with 4 pins - measured the red and blue pins in the pic) and it kept around the 4.+ mark. The other LED (sender? the 1 with 3 pins in the pic) i didnt seem to get any measurements from.. ???
So, is it working then? I’m getting midi output it seems so thats a start - whether or not it’s the right output is another thing…;p
These diy encoders have took a lot to make tho and i’d really like to use them so what to do next? How is the 3 pin LED connected? does that go to the dout module - how would that effect things when i’m configuring a full featured LC box?
Note that optical encoders contain a LED which has to be powered - just take a 470 Ohm resistor in serial to the LED and connect it with Vss/Vdd (+5V) of the Core or DIN module.
Thats that covered then Logic v-pots here we come ;D ;D
I have looked at your old posts a few times and have been asking around for old mouse donations (everyone wants an optical mouse so I might have 32 encoders!!!)…
Keep us posted (no pun intended) about how its working because one of my obsessions is recycling old teknology for fun projects like this
On another group we are talking about using the optical sensor from a optical mouse to measure the speed of a moving roll of paper. We found the sensor at http://www.semiconductor.agilent.com and do a quick search on HDNS-2000. They have data sheets, application notes etc. available for download. This may eliminate the need to have an encoder wheel with a pattern of “spokes”, just a moving wheel under the sensor. Just another idea for the group.
Actually we are using a cheap optical mouse. The HDNS-2000 is the chip used in these and would have to have the 4 parts - the sensor chip, the led, the lense with light pipe, and the led clip. I was trying to point to the datasheet for the chip itself. We are planning on mounting the mouse on the bed of our scanner and read the paper movement into our scanning software. The same thing could be done by mounting a optical mouse and using a moving disk or roller or anything that would move so the mouse could detect it without need for a spoked encoder wheel. It’s at least something to think about. (We are planning on scanning piano rolls [band/fair organ, craank organ, etc rolls and books] and saving the data to archive rolls so they are not lost. Lots of old rolls have only one copy to be found! Also, part of the project will convert the data to MIDI - and that is the part the MBHP will play for me. See http://www.iammp.org for more info and http://groups.yahoo.com/group/Rollscanners/ for the discussoin archive. Also, if you are interested in Mechanical Music, check http://mmd.foxtail.com for the Mechanical Music Digest. They have some discussions of MIDI stuff from time to time.
that the +5 provided from the core would be fine ???