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It should be fairly straightforward to write and read a 25xxx eeprom thru the SPI bus using the pc serial port with Keil software. But nowhere do I find the DB-9 to SPI connections. Which pins connects to sck, mosi, miso,cs ? Can you help? Thanks, John
Could you define standard configured DB9 please ?
I can't but here it is: http://www.national.com/an/AN/AN-917.pdf Erik
Well,well,well. I seemed to have overlooked the uart in the grand scheme of things. I see what you mean now. The programming software is independant of the rs232 conections. They are defined by the 232 standard and the uart. All that is unclear now is the uart to spi buss connections.
"All that is unclear now is the uart to spi buss connections." After reading the exchanges in this thread, I am still somewhat unclear regarding your requirements.
Are you designing your own PCB that incorporates an nRF9E5 and EEPROM? Actually 2 pcbs. One contains the nrf9E5, eeprom and connectors for the adc and i/o port. This plugs into the other which contains a uart and a serial to usb translator. So you can load your app code to the eeprom via the pc usb and then plug it into the app circuit. Taking the EEPROM totally out of the equation for this question, will the application running in the nRF9E5 need to communicate via the MCU's UART and RS-232 to provide some user interface or debug output to a terminal emulator or anything similar? I dont think that is necessary. C That is, again taking the EEPROM totally out of the equation for this question, is there any reason whatsoever that your PCB would require an RS-232 driver/receiver? Just to program the eeprom. Does your design require (re)programming of the EEPROM in-circuit without removing it from your PCB? The eeprom is a smd. Have to plug the board into the programmer to reprogram it. So really all I need is a serial eeprom programmer running thru the pc serial port. And software to flash the eeprom and compile the code and all that. Its an evaluation board and a programmer with expandable i/o interfaces.
"... the other which contains a uart and a serial to usb translator. So you can load your app code to the eeprom via the pc usb and then plug it into the app circuit." Then if you are using something like an FTDI FT2232C http://www.ftdichip.com/Products/FT2232C.htm you can dispense with its USB-to-UART functionality and use its USB-to-SPI mode http://www.ftdichip.com/Projects/MPSSE/FTCSPI.htm or in its "Bit-Bang IO" mode to program your EEPROM.
At a glance that sure looks like a possibility. Cost is one of the most important factors. I noticed that they have footprints and schematics for Protel. That helps a whole lot. Nordic reccomends : http://www.silabs.com/tgwWebApp/public/web_content/products/Microcontrollers/Interface/en/interface.htm However I came across this earlier this morning: http://www.lancos.com/e2p/si-prog-v2_2.pdf which seems to be what I have been looking for all along. It comes with a nice GUI that loads the hex code. Most of the circuit is power supply.The pertinant part is the db9 to 25xxx230 eeprom wiring. Wonder why they used a transistor to switch cs ?