| ??? 04/23/08 11:36 Read: times |
#153866 - There are some internal issues too Responding to: ???'s previous message |
Michael said:
1 - Let us consider that for any reasonable installation covered by the distance that the RF field works is of finite size. Yes , its a radii of 5Kms LOS. Michael said:
2 - It is only feasible to fit a reasonable number of the "slave devices" into the RF field region. You can say that , but there are possiblities of additional , nodes being fixed in future . I doubt the masters would skip those nodes keeping the lethargy point in, as that would require maskers to know these newely added guests . For this very reason , I ask for slaves to provide their addresses when the masters beacon is heard. Michael said:
3 - Consider that some human action is needed to install, setup, or deploy the various slave devices. Yes , its needed . Michael said:
4 - Keep in mind that it sounds like from AP's original posting that the slave devices are an original custom design just for this project/product line. Yes , these are location specific . Michael said:
OK here is the basic idea that relies upon the above four basic concepts for its feasibility. I would equip each slave with some type of wide address source that is setup to be unique for all conceivable types and quantity of each type ever to be made. Burn the code in at manufacturing time, use an off the shelf ID code chip, or get some serial EEPROM pre-programmed from Arrow or Avnet or RS Electronics that has a non-repeating 48 or 64 bit ID code embedded in it. Use such as the slave address. Design it so that the slave device MCU can read the ID code and use that as his/her address. MCU and EEPROMS already attached . Michael said:
Provide for a local interface at the slave wherein the slave MCU can spit out its ID to some type of interface. This could be done via a local RS232 port, IR Transmitter LED, I2C header under the battery door, SD card interface slot, USB Stick interface, local RF transmit mode where slave and address reader are put inside a metal setup box, RFID tag system, magnetic coupled coils, serially coded blinked LED.... i.e whatever seems to fit the scheme of things but make it a local interface that can be used to gather the address of slaves. Each slave needs a very simple way to put it into its "spit-out-your-address" mode. This could be a button, magnet that closes a reed switch, an access door switch, looped back contact in a battery box connector.... i.e find something suitable that is cheap and works. Michael said:
Make a slave address collection tool that can be used to gather all the slave addresses in an installation. This could be a datalogger device, an RFID reader, an RS232 connection, a laptop, a carry around version of the master unit. Use your imagination here on a way that suits the product deployment scenario, the type of interface used, the amount of development time you have for this. Depending upon the nature of the product suite that this is all part of it may be even possible to make this be a really cool hand held controller that becomes another revenue item for the product line. Or it could be a re-deploy thing where the connection is done with a programmable PDA or handheld type device. Fixup your master mode product with a means to accept a download of the gathered slave unit addresses and save them to internal non-volatile storage. The problem here is , even if I know what slave adresses are being installed . We dont know if we are going to add a few more in a short time . That would require a database management system and documentation , which will definitely collapse. Please have a look here :http://www.8052.com/forumchat/read.phtml?id=153865 I do have the capablity to implement CSMA/CA in the radio layer , but need to figureout how to effectively do that . Regards/ Ap |
