I used pic18f4550 same as 2550 and completed a project using 6 analog joyst= icks=20 plus 16 buttons multiplexed , rs422 and usb. it worked fine. you can use 25= 50 to=20 get your job done. pic24/32 are faster parts better but if you never worked with them beginnin= g you=20 may have=20 headache until make them work specially USB hid.=20 AA ________________________________ From: Yigit Turgut To: Microcontroller discussion list - Public. Sent: Mon, June 6, 2011 12:59:05 PM Subject: [PIC] 18F2550 Analog I/O Limits Hello Everyone, I need to make a design decision where I need to drive ; 1- a ppm laser diode module (integrated apm - TE cooling) 2- a PMT (photo multiplier tube) 3- an APD (avalanche photo-diode) 4- a unipolar/bipolar stepper motor 5- An analog input of 0-10VDC Hands currently on a PIC 18F2550 conducting usb data transfer. It seems that 18F2550 is capable of handling 5 analog inputs simultaneously where I have question marks about the overall performance and response of this MCU. I want the system to be compact and smart where it seems that all necessary algorithms can be handled by only one amount of 18f2550. Since I didn't push the limits (bandwidth - performance) of this unit I don't know if it's capable of doing the job as expected. Do you think this mcu can simultaneously read 5 analog inputs and send the data through USB without sacrificing any performance or precision ? I don't want (who wants right) an obstacle in development after I start the process which will change the deadline and thus roadmap of the project. I am sure more experienced PIC users will quickly come up with an answer, also any guidance is appreciated. Have a nice day --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .