>-----Original Message----- >From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] >On Behalf Of Xiaofan Chen >Sent: 25 June 2007 14:23 >To: Microcontroller discussion list - Public. >Subject: Re: [EE] anyone worked with PIC24? > > >On 6/25/07, Rich wrote: >> Thanks for the reply. All information is useful. How much >memory did >> you add? I have not worked with SPI before so I want to try it with >> memory and a 24-bit A/D. >> > >24-bit A/D, should be a Sigma-Delta one. Take good care of the >SPI communication because I am having big problems with the >SPI communication to an AD7731 (an 10 year old parts but still >a good one for its price). The noise in the SPI clock is >causing data to jump to the top or freeze in continuous >conversion mode. I am not using a PIC24 though but an ARM7 MCU from TI. We have suffered from SPI problems like this in the past. Have you tried limiting the slew rate of the MOSI, CLK and CS signals from the ARM by using series resistors close to the micro? Regards Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. ======================================================================= -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist