This is a multi-part message in MIME format. ------=_NextPart_000_004D_01C9057E.41BD8F50 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Progressing with the network sensor project of a couple of weeks ago The set-up settled on is a group of up to 5 PIC-based analogue and digital sensor units per network node. Each unit will have a unique ID and they will respond to network requests directly when called or separated in time according to their ID if called as a group. Either way there would/should be no collisions A prototype with just one PIC unit has been installed remotely and tests OK, reporting various voltages, switch states etc. Kind of cool reading a battery voltage and temperature several miles away. I'm sure the novelty will wear off Two questions - 1) how could MAX232's be paralleled ? 2) I'd rather not use a transceiver IC if the job could be done with a few transistors. I realise this will mean making a -ve voltage for data '1', which may have to be distributed too The background ...... and attached graphic Network interface to that PIC's Rx and Tx is via a MAX232. The next step is to build a few more of these units and stack them up in parallel, connected by a 4-way cable of 0V, 5V, Rx, and Tx, to a distance of a few metres So all the MAX232 Rx are tied together, ie all the pin 8s or 13s. For the Tx's I think I'd have to use at least one transistor to isolate the MAX232 driver from the Tx line going back to the network. That's assuming I stick with the MAX232, but I'd rather not if it can be done a better way (cheaper, no unused transceivers) if possible ------=_NextPart_000_004D_01C9057E.41BD8F50 Content-Type: image/gif; name="parallel_MAX232.gif" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="parallel_MAX232.gif" R0lGODlhHQE4AYAAAAAAAP///ywAAAAAHQE4AQAC/oyPqcvtD6OctNqLs968+w+G4kiW5omm6sq2 7gvH8kzX9o3n+s73/g8MCofEovFIBCgjyiXyCeUBDtNHNWpoOrFc1vXKAHfF3fLpa22W0VmzG8Rm jhFT8vt+iUPsRzEfDyihtzD45BeImLfloDZHFfCXKDkp12ZJiZmpucnZ6fkJGsoRmUCKZCrq1piG mrSYGlgHaTXbGiRrCxtlmzvUqwvFe/cLfDpBDIRcXCT8przsezwMjdisSh0r7YwNaG32zO3jvRY+ LWhe/q19na5+vt1O/s4ezzXuWI91b5/PP+/eL9g6gAF/aDmIMKHCgwILJisBbkZEhygmhmlIsYdF /kIYM+7YqACkC5Ee4UDsWBIHyUeGUn482dJljpWX+sicCdPYzRs0Z8XcWaMnsVcwegKtIDQPJKOV jkrMSeELU0ZOaSS14Gcqx6oyriIlpJUO165QB5YK63PsC2QMt35lpBWt2lIaIg1lwlSuISeHNNZl 6fOuIDurMEwtzOxRXyl/FQOOihRMobckJt9iaZln48eCI6etqbSizsCPX2ZYvHSh6tNZVbt+DTth SLBUFtZGfJtoA9mA0egNbVhsZqpYZYndXHl36d7LL+1j3uY31s1sOg8+/hl4Wex84nRvflF5TenT k5fHCxYceeiznYfPTnz3q/WQzVOGeybFH8ve/t8/9zeCdbSJRhZo7H1noHjoiCAgHWjRlxaCEfpn FkEhNLhUCxDyxx5dCb4HT4DaZTjSUx/259Z/+mzXlG4qbAgeiu3Bp2CIDCrl4gowntghdxXKI2Jx QZlI44Q8fuiWjSE1IpVdKJV4pJEzqrhLfMZlBuEGOxYpo4dFJklPirX8Y8SWEnKI5IwgfqmDk9Gx iZ1NBXLZY501gpnlj7m92ZScMaAppZdUBvrQncbt8aSGMdpJaHwK5qknaFVgmagXi7onJpmp+ZaY obc5WqZEWoQxaha2mRobKocK4ZWf4UBaX5B/KgPrZZ3KOtKq982lI4sVDUcLr4ra9yJquwpL/iCu ZxB2GrKWEgvRfs06+6IiuIH3QY5pBkttsrHSWZmq03ab33ljWkKrbtp6aS650A62yqFscdYLre6W +xZqAtaBIXr3+sqtZA6mWmptrBHc1r/KzsPptmvyO+Ixtd5knbwOU2jwt8cq7EGrkRE26J0cdwzw KOIGN/KFJXewrr0pm/RugNKi/DLJMYcLpsY1I6eyF8bqvDPNN+aKLaJBj7KyCUu4fDTPMM86btNC 9zya1BFnW6nVfVLtqtZA21y115Ei/ZPYY2uZtdmkIkxw2mqfHefUAnOG6qd1w/220VsrkvG56LrX MJxx590uqHyb6hhmamYXMuEiP/4VLon3/s0dGY07njPkkEkeKFGWD2445ppqLg3nCU8KOrCLiz76 mqGh3hfq4ym+Mevc6j0t7HQJ3BaTBeNu+96klx088KGvWHzrmSOfvPHDh9286893Hf3y1rtd/eVJ VH979/hwfz27QIK/+vShkh8+6MxHzzbC2Dvu8a3sJy0O+PFvz/390eRPv1/838wq+/WPMf9bGP6y N0DTIBCAtlqgAfeQp4nJRH+0WJe3mkdBK61Hgi7JoKGkw8GUeFB6FuQaBhOIrRKCbX7FudbFyucg /QhwajD03oBQaDamdQlviFuSen4VwkQwzW+CS99ZfOS0pwUxG3ITn/Lw87PamXAsQ2Rc/vvSdZYr avE1NXTKEFfVrzQwDm1Ko5YOGWVD/KDxiSvk1QiN2MMsktGBQ5NiDMt4wbm8sYskwhcLH5jGPuax eHt0oiBlWMA6akyFUyQkDiO0wRkCkiqMZKDoCnlHIv0xPbJLzfECmMgpkQZJS3Re8Nw0plaUMpCs QyXnTAlKOvpQd8LbnyzFpyvzEfCWcevkzKDnSE/dTXq23GQji3lCS/4qasmc5LKKSEzbYTJbqtPl 26ZpMkOyEXPYZA0cv3nNRwopmrBspbVylBdSVDF5FSOnlk52tVNqx2LQTM8Ny8nKS54zcPMaT72Y yc7XsWtfh9wmqSQZq7mhim1HNMwW/hG6Dn6OCGKFu04o/0HPfn6mkvXkIzfF6ckl8RCcauumRfP5 SXMq850otWZJQRqVX1ZUnivtGLNoGExnMiiKBiWcSVn6QpLmEKYsXWdOFbkWo9JUp/W7KNaIF9Ca 7tKYT6PeUY8ZS6o+FZin3CIXoYq+ekZEX3Ga1BbiVclV7kR7B40jGP/GJ7+xVZojlU/f3gofY81V pbXcnFytmKLP9TSqfS3dufTgOTXlQq0Uq+tFTFewTtKomuoj3149REvaIZZ2X7OsY7eS2bjWolS+ c6FQ+YpPrnp2sAcMa9G0WSXXVtajVkXfZQ0i29nC9n3NTG1tV1tYsNr2sw3M7W2b/ppbsS4Ig151 DW/z9tMhObWN8ustVotr3aqej5fUbW12t/pb1F63UNxl2XPDKVUFarW7yCQsUk86p/Wadzocfe9V tcuwSE53vruqL3/lS7aN+TeJS7UvLAccT7ru053uRHBnxWvHMGYyvS8dV3USLFIfzjFajFXSfehp x3tS1qWU6bCF+qtbBtOGp8SdqRd5JpkrenNgza0xbkx84m+B+MF2ZTFrMdwJ047Kxym2Emd5nGFM AdTAngDUGINL4JbGcWAb1mNzBKtcCl/MwVD+rygmE9nXFhmn+OSy8hJWEmAFrstkDqSZI6XQC0UW rU2ym2GhBKc1+7bNoXtzZ3kn/maMbnRCEr3zsCZLNyQvGXh+luLpOnq7XPZyoJjhS2kNZlaLxEuO Yw40nx+lX9DutoVnPROWCe0YXwZmx+BtdRZ9qa27NLrNm32q5X4WZz5xqkkWQ7OrvSyoUX5pKBF8 1OQCfFNEJ+hKqQbcsdvrI0mfVjMgYrWFZzdouGYqlei6krX9RyFp0xbcRTkOac+d6cTajaJLQ1ym PR3fWYo2peSlhoTIvThxjxq3y/jdvpU6alRqW6bbXeuiIyyoWJ+3Hmp45bvNXerDqpup+J5gDwsd V2//tdMuxq7FpcSvwvS62Sr+NL+le/BES1k8/fmORMUdXZYBvODVRmR1djzy/gyxOuZ10ffKRUPa SsPu0u6GuFQk/ot2Y3qY3T66t089XpwFddwyfLliZNewReS83SMeJNU7LrN9k/gkF053RodMN6vD yt9j/3HPpw3pMpZdUkfuHKrfhGOOh9imbY872Q80OVWbVTiJ4zq8bUBsIT+T3ozvVZeYlDG0Zlvy T6e5oOEOQTZjvhoA0rGR0gWyFvtd7L4wbXXhddZGMWzCmv/65qsiGLK2i6J7X1vK/9WZOGuxofu0 cXMVlvvAT7Sgrcdvytp5YeDEuPZadiNIr8VI+uQdEzy3656TO/rij7PvcDH90aqf+ZIDuWng9xfp lX94cpUfvtnHnc9Htn6JkaV/kWKLf0zb373pN5mo2STW+zlmfyqxRvDHf9jXK81ngGtRgAnodcDG gG2ygA/IYb7naxJYDLKHbXRmZxaIeEcnWlgnfF3HgYvXR3gFdUQ2go73V1kRWK6XgslhOvSyOrn2 guUGWZuWbcFWg1bxN7GjZJ+3g9IVWkQUcpZmdkGIhEmohEvIhE3ohE8IhZtQAAAAOw== ------=_NextPart_000_004D_01C9057E.41BD8F50 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist ------=_NextPart_000_004D_01C9057E.41BD8F50--