Hi Matt, I'd recommend you choose a 3.3 volt picmicro, rather than trying to interface 3.3v parts to a 5 volt picmicro. It could be done, but why put yourself thru all of the hassle?
About switching modes -- we may never find a generic solution for that, since there are so many chips out there, and they don't all quite behave the same way. Take a look at this web page, where this type of problem is being discussed (he calls it multi-slave configuration) http://elm-chan.org/docs/mmc/mmc_e.html I expect many projects will just have to use our JAL SPI library as a starting point for their own, custom, version of the library. It is unfortunate, but sometimes the most practical solution. We're only talking about a hand-full of lines of code anyway. William On Oct 29, 12:47 pm, mattschinkel <[email protected]> wrote: > What is the correct way to interface a 5v PIC input/output to a 3.3v > component? Asuming the pin will change from input to output throughout > the program. > > I will make a tutorial for this chip but need a correct circuit. > Currently I am using 47nf cap parellel to a 4.7kohm resistor direct > from pin to pin. > > Matt. > > On Oct 28, 5:43 am, William <[email protected]> wrote: > > > > > Hi Matt, > > > Nice to hear from you! > > > How about "sr23_" for prefix to the names? And I suppose you'll put > > the library under include/storage/sram/sr23k256.jal ? > > > Take care: that is a lower-voltage part (not 5 volt tolerant), and > > you'll need a battery if you want persistent storage. Many picmicros > > will operate at lower voltages, but sometimes only at a reduced > > frequency. Also some older ICSP flash-burners will not work at the > > lower voltages. The ICD2 is fine, and I'm sure many others are also. > > > William > > > On Oct 28, 2:26 am, mattschinkel <[email protected]> wrote: > > > > I am creating a lib for Microchip's 23k256 SRAM (costs about $1) > > > > similar to 24LC256 EEPROM but much much faster (up to 20MHz) and uses > > > SPI bus instead of I2C (spi mode_00) > > > >http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en539039 > > > > What should I name the variables & procedures since I cannot use > > > numbers as first characters in procedures & vars. > > > > eg: > > > > 23k256_init() is > > > > const byte 23K256_READ = 0b_0000_0011 -- Read data from memory > > > array beginning at selected address > > > const byte 23K256_WRITE = 0b_0000_0010 -- Write data to memory array > > > beginning at selected address > > > const byte 23K256_READ_STATUS = 0b_0000_0101 -- Read status > > > register > > > const byte 23K256_WRITE_SETTINGS = 0b_0000_0001 -- Write settings > > > register > > > > I'm an SPI kind of guy :o) > > > Matt.- Hide quoted text - > > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/jallib?hl=en -~----------~----~----~----~------~----~------~--~---
