Post by thread:[OT] Using a mouse as a cheap incremental encoder?

I am working on a project where I use a BOURNS mechanical incremental encoder to modify the frequency generated by a DDS. The DDS and the encoder are connected to a PIC. I would like to use a higher resolution optical encoder but the price is prohibitive. I am now considering using a PC mouse, or at least some part of it as an encoder. The standard PC mouse seems to have a DATA and CLOCK output. Does anyone here have detailed information on the protocol used? Any information on the pinout of the 6-pin header that is frequently found on the PCB? Any information on how the mouse is normally connected to the PC hardware? thanks, Charlos Potma spam_OUTcharlos.potmaTakeThisOuTrivm.nl

Check out: http://www.worldaccessnet.com/~dstixrud Larry ---------- {Quote hidden}> From: Charlos Potma <.....Charlos.PotmaKILLspam@spam@rivm.nl> > To: PICLISTKILLspamMITVMA.MIT.EDU > Subject: [OT] Using a mouse as a cheap incremental encoder? > Date: Tuesday, June 23, 1998 3:20 AM > > I am working on a project where I use a BOURNS mechanical > incremental encoder to modify the frequency generated by > a DDS. The DDS and the encoder are connected to a PIC. > I would like to use a higher resolution optical encoder but > the price is prohibitive. I am now considering using a > PC mouse, or at least some part of it as an encoder. > The standard PC mouse seems to have a DATA and CLOCK > output. Does anyone here have detailed information on the > protocol used? Any information on the pinout of the > 6-pin header that is frequently found on the PCB? > Any information on how the mouse is normally connected to > the PC hardware? > > thanks, > Charlos Potma > .....charlos.potmaKILLspam.....rivm.nl

On Tue, 23 Jun 1998 09:20:36 +0200 Charlos Potma <EraseMECharlos.Potmaspam_OUTTakeThisOuTRIVM.NL> writes: > I am now considering using a >PC mouse, or at least some part of it as an encoder. >The standard PC mouse seems to have a DATA and CLOCK >output. Does anyone here have detailed information on the >protocol used? Sounds like a PS/2 type mouse. These use two TTL lines with bidirectional synchronous signals very similar to a keyboard. A serial mouse would be simpler to use a since it sends data one way over one wire. The data is just standard asynchronous at 1200 baud. Microchip made some pre-programmed PICs once to use as mouse controllers. The data for these had fairly good descriptions of the signal format. For a Microsoft-type serial mouse, groups of three 7-bit characters are sent LSB first with start and stop bits just like standard async data. The data is sent only after the user activates something on the mouse, if it is sitting still no data is sent. The characters are: 1(LB)(RB)(V7)(V6)(H7)(H6) - (LB, RB are 1 if the button is pressed) 0(H5)(H4)(H3)(H2)(H1)(H0) 0(V5)(V4)(V3)(V2)(V1)(V0) The PIC would look at the MSB of each character and wait until one with a 1 is found, indicating the start of a new packet. Then it could accumulate the V and H bits in proper order. I think the two 8-bit numbers are two's complement reperesentation of how far the mouse has moved since the last report. _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866]

On Tue, 23 Jun 1998, Mike Keitz wrote: > On Tue, 23 Jun 1998 09:20:36 +0200 Charlos Potma <Charlos.Potmaspam_OUTRIVM.NL> > writes: > > I am now considering using a > >PC mouse, or at least some part of it as an encoder. > >The standard PC mouse seems to have a DATA and CLOCK > >output. Does anyone here have detailed information on the > >protocol used? > > Sounds like a PS/2 type mouse. These use two TTL lines with > bidirectional synchronous signals very similar to a keyboard. A serial > mouse would be simpler to use a since it sends data one way over one > wire. The data is just standard asynchronous at 1200 baud. Microchip > made some pre-programmed PICs once to use as mouse controllers. The data > for these had fairly good descriptions of the signal format. I thought that I'd seen simple (no IC's or active components, just wires) adapters to go between a serial mouse and a PS/2 bus mouse port. If what you are saying is true, how can a simple adaptor convert an asynchronous signal to a bi-directional synchronus signal? I could be wrong, its just that I seem to remember these adaptors. THanks, Sean {Quote hidden}> > For a Microsoft-type serial mouse, groups of three 7-bit characters are > sent LSB first with start and stop bits just like standard async data. > The data is sent only after the user activates something on the mouse, if > it is sitting still no data is sent. The characters are: > > 1(LB)(RB)(V7)(V6)(H7)(H6) - (LB, RB are 1 if the button is pressed) > 0(H5)(H4)(H3)(H2)(H1)(H0) > 0(V5)(V4)(V3)(V2)(V1)(V0) > > The PIC would look at the MSB of each character and wait until one with a > 1 is found, indicating the start of a new packet. Then it could > accumulate the V and H bits in proper order. I think the two 8-bit > numbers are two's complement reperesentation of how far the mouse has > moved since the last report. > > > > _____________________________________________________________________ > You don't need to buy Internet access to use free Internet e-mail. > Get completely free e-mail from Juno at http://www.juno.com > Or call Juno at (800) 654-JUNO [654-5866] >

part 0 3247 bytes content-type:text/plain------ =_NextPart_001_01BD9ED9.67C20AA0 Content-Type: text/plain The mice that work with those adapters ain't your everyday old mouse. They need to have both interfaces built in. PS2 mice have clock and data lines. Older mice have RS-232 RX & Tx. The newest mice have all four signals. The designers were clever selecting the pins, so that the unused signals are connected where they will do no harm to the existing hardware. ------------------- I thought that I'd seen simple (no IC's or active components, just wires) adapters to go between a serial mouse and a PS/2 bus mouse port. If what you are saying is true, how can a simple adaptor convert an asynchronous signal to a bi-directional synchronus signal? I could be wrong, its just that I seem to remember these adaptors. ------ =_NextPart_001_01BD9ED9.67C20AA0 Content-Type: text/html <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> <HTML> <HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"> <META NAME="Generator" CONTENT="MS Exchange Server version 5.5.1960.3"> <TITLE>RE: [OT] Using a mouse as a cheap incremental encoder?</TITLE> </HEAD> <BODY>      The mice that work with those adapters ain't your everyday old mouse.  They      need to have both interfaces built in.   PS2 mice have clock and data lines.      Older mice have RS-232 RX & Tx.&nb sp; The newest mice have all four signals.       The designers were clever selecting th e pins, so that the unused signals      are connected where they will do no ha rm to the existing hardware.           -------------------           I thought that I'd seen simple (no IC' s or active components, just wires)      adapters to go between a serial mouse and a PS/2 bus mouse port. If what      you are saying is true, how can a simp le adaptor convert an asynchronous      signal to a bi-directional synchronus signal? I could be wrong, its just      that I seem to remember these adaptors . </BODY> </HTML> ------ =_NextPart_001_01BD9ED9.67C20AA0--

On Tue, 23 Jun 1998, Sean Breheny wrote: > > I thought that I'd seen simple (no IC's or active components, just wires) > adapters to go between a serial mouse and a PS/2 bus mouse port. If what > you are saying is true, how can a simple adaptor convert an asynchronous > signal to a bi-directional synchronus signal? I could be wrong, its just > that I seem to remember these adaptors. Hi Sean, Those adapters only work on highly intelligent mice, the kind that figure out what they are hooked upon powerup and communicate the correct way. All the new Logitech mice are like that, probably some others too. -Bob

Hi Charles & Larry Cool Web site but what is not said is the output waveform from the detector section is 2-bit quadriture as follows clockwise rotation .---. .---. .---. [a]___| |___| |___| |___ .---. .---. .---. .- [b]_| |___| |___| |___| counter-clockwise rotation .---. .---. .---. .- [a]_| |___| |___| |___| .---. .---. .---. [b]___| |___| |___| |___ Each mouse will have 4 outputs 2 for horizontal and 2 for vertical Counting the transitions of both outputs and adding them together doubles the counts per revolution Detecting which output leads ( which goes positive first ) will tell you which direction you are turning Please excuse the commercialism but the company I work for sells mouse guts made by Logitech. They simply buffer the quaditure waveforms with a ttl inverter and sends them to the computer. The small pcb has all of its parts including mounted encoder wheels and micro switches. All that is missing is the cable and case. Schematics are included. Price is 2 for $5 + S/H >{Original Message removed}

Sean Breheny wrote: {Quote hidden}> On Tue, 23 Jun 1998, Mike Keitz wrote: > > > On Tue, 23 Jun 1998 09:20:36 +0200 Charlos Potma <@spam@Charlos.PotmaKILLspamRIVM.NL> > > writes: > > > I am now considering using a > > >PC mouse, or at least some part of it as an encoder. > > >The standard PC mouse seems to have a DATA and CLOCK > > >output. Does anyone here have detailed information on the > > >protocol used? > > > > Sounds like a PS/2 type mouse. These use two TTL lines with > > bidirectional synchronous signals very similar to a keyboard. A serial > > mouse would be simpler to use a since it sends data one way over one > > wire. The data is just standard asynchronous at 1200 baud. Microchip > > made some pre-programmed PICs once to use as mouse controllers. The data > > for these had fairly good descriptions of the signal format. > > I thought that I'd seen simple (no IC's or active components, just wires) > adapters to go between a serial mouse and a PS/2 bus mouse port. If what > you are saying is true, how can a simple adaptor convert an asynchronous > signal to a bi-directional synchronus signal? I could be wrong, its just > that I seem to remember these adaptors. they exist, i have one, it is a ps2 to rs232 converter. it does not seem to work though, when i plug my trackball into it and then plug it into my rs232 port(com1) it is not recognised, but trackball works when i plug it into rs232 port. maybe it only eorks for mice, not trackballs {Quote hidden}> > > THanks, > > Sean > > > > > For a Microsoft-type serial mouse, groups of three 7-bit characters are > > sent LSB first with start and stop bits just like standard async data. > > The data is sent only after the user activates something on the mouse, if > > it is sitting still no data is sent. The characters are: > > > > 1(LB)(RB)(V7)(V6)(H7)(H6) - (LB, RB are 1 if the button is pressed) > > 0(H5)(H4)(H3)(H2)(H1)(H0) > > 0(V5)(V4)(V3)(V2)(V1)(V0) > > > > The PIC would look at the MSB of each character and wait until one with a > > 1 is found, indicating the start of a new packet. Then it could > > accumulate the V and H bits in proper order. I think the two 8-bit > > numbers are two's complement reperesentation of how far the mouse has > > moved since the last report. > > > > > > > > _____________________________________________________________________ > > You don't need to buy Internet access to use free Internet e-mail. > > Get completely free e-mail from Juno at http://www.juno.com > > Or call Juno at (800) 654-JUNO [654-5866] > >

In message <KILLspamPine.SOL.3.91.980623140529.23306A-100000KILLspamtravelers.mail.corn> ell.edu>, Sean Breheny <RemoveMEshb7TakeThisOuTCORNELL.EDU> writes {Quote hidden}>On Tue, 23 Jun 1998, Mike Keitz wrote: > >> On Tue, 23 Jun 1998 09:20:36 +0200 Charlos Potma <spamBeGoneCharlos.PotmaspamBeGoneRIVM.NL> >> writes: >> > I am now considering using a >> >PC mouse, or at least some part of it as an encoder. >> >The standard PC mouse seems to have a DATA and CLOCK >> >output. Does anyone here have detailed information on the >> >protocol used? >> >> Sounds like a PS/2 type mouse. These use two TTL lines with >> bidirectional synchronous signals very similar to a keyboard. A serial >> mouse would be simpler to use a since it sends data one way over one >> wire. The data is just standard asynchronous at 1200 baud. Microchip >> made some pre-programmed PICs once to use as mouse controllers. The data >> for these had fairly good descriptions of the signal format. > >I thought that I'd seen simple (no IC's or active components, just wires) >adapters to go between a serial mouse and a PS/2 bus mouse port. If what >you are saying is true, how can a simple adaptor convert an asynchronous >signal to a bi-directional synchronus signal? I could be wrong, its just >that I seem to remember these adaptors. I think that Charlos's best bet is to just use one of the encoders and forget about the mouse electronics. It will generate an in-phase and quadrature signal which can be sorted out with software or hardware to get the required direction and count information. Leon -- Leon Heller: TakeThisOuTleonEraseMEspam_OUTlfheller.demon.co.uk http://www.lfheller.demon.co.uk Amateur Radio Callsign G1HSM Tel: +44 (0) 118 947 1424 See http://www.lfheller.demon.co.uk/dds.htm for details of a simple AD9850 DDS system. See " "/diy_dsp.htm for a simple DIY DSP ADSP-2104 system.