Post by thread:IIC with slow devices

Hi all, >the data takes about 1 second to obtain. Is there a way >I can get the master that sent the request to wait for >the PIC without the PIC becoming the master and >transmitting the data back. Clock streching is the answer. For an example of this, you can look on microchip's web site and look for the data sheet on 16C7X. On page 96 you will find that the slave holds the clock line low while it serveces it's interupt routine. Regards, Brian. -------------------------------------------------------------------------- --------------------------------- Code examples on www3.mistral.co.uk/brian.clewer/ -------------------------------------------------------------------------- ---------------------------------

Clewer,Brian wrote: > Hi all, > > >the data takes about 1 second to obtain. Is there a way > >I can get the master that sent the request to wait for > >the PIC without the PIC becoming the master and > >transmitting the data back. > > Clock streching is the answer. For an example of this, you can look on > microchip's web site and look for the data sheet on 16C7X. On page 96 > you will find that the slave holds the clock line low while it serveces > it's interupt routine. You are quite right, except that this method only works (well) for single slave setups. For multi-slaves, you really should use a polling technique. -- Friendly Regards Tjaart van der Walt spam_OUTtjaartTakeThisOuTwasp.co.za |--------------------------------------------------| | WASP International | |R&D Engineer : GSM peripheral services development| |--------------------------------------------------| |SMS .....0832123443KILLspam@spam@wasp.co.za (160 chars max)| | http://www.wasp.co.za/~tjaart/index.html | |Voice: +27-(0)11-622-8686 Fax: +27-(0)11-622-8973| | WGS-84 : 26¡10.52'S 28¡06.19'E | |--------------------------------------------------|