Now I can send and receive . How should I send a number for example 987 to other PIC? And How should I read data ?
On Wednesday, April 21, 2021 at 10:22:01 AM UTC+4:30 majid ebru wrote: > Thank you > > Ok I use RS232. > > But I can't read correctly data ,yet😫😢😫😢 > > Please guide me > > When I send "0x052" from pic1 , I received data in pic2 , but it is not > correct > > > If serial_sw_read(char)) then block > .... > lcd_cursor_position(1,5) > print_byte_hex(lcd, char) -- ====> print 2B > lcd_cursor_position(1,10) > lcd = char. --. ====> Print + > ...... > > > On Wednesday, April 21, 2021 at 10:02:54 AM UTC+4:30 Kiste wrote: > >> Thanks for the additional information, 800m is something very different >> from 20m ;-) >> >> I can imagine that 20m at 5V ground-referenced is doable, but when you're >> starting, better stick to the specifications and try your luck when you >> have a bit of experience. >> >> I myself am at a similar project, like 15 meter, and I want to use as >> little standby current as possible, and no twisted pairs. It's >> uni-directional, with constant-current pullup at the receiver and optically >> isolated pulldown at the sender with 1200 baud... First test of the concept >> in a few days ;-) >> >> If standby current was of no concern, I'd use RS422 or RS485 >> drivers/receivers, true RS232 is old-fashioned and needs to many >> components. >> >> >> Greets, >> Kiste >> >> Am Mittwoch, 21. April 2021, 07:02:46 MESZ hat vsurducan < >> [email protected]> Folgendes geschrieben: >> >> >> >> >> >> Oliver, I remember the problems I had with an EIA232 with +/-8V output >> running at 800m at 9600bps. Everything works until due the transceiver >> heating the voltage dropped at +/-7.6V...:) >> The length is given by the voltage at the level converter of the >> transmitter output. All level converters with charge pumps are not able to >> give more than +/-8V...+/-10V in the happiest circumstances. >> Oldest/goldest EIA232 worked at +/-25V up to 2km. >> For 20m you do noy need any level converter at the output of your PIC, >> just a twisted pair RX-GND TX-GND (CAT5 ethernet cable is perfect) and an >> open collector transmitter ( a gate) with pull-up resistor in the receiver >> end (at 20m distance from the transmitter). >> However Majid, I think you need first to learn jal and for that there is >> a learning curve which has to be passed.... >> Please start with the examples, compile them, make them run, modify them >> as you wish and post only when nothing works for you after three days of >> trying...this will help you more than you may believe right now... >> best wishes >> >> On Wed, Apr 21, 2021 at 7:28 AM 'Oliver Seitz' via jallib < >> [email protected]> wrote: >> > Hi Majid, >> > >> > SPI is designed for centimeters, I don't think it can work reliably >> over 20 meters. >> > >> > RS232 at 9600 baud is ok for 150 meters, if you're using real RS232 >> drivers and receivers like from the MAX232 series. The PIC controller does >> not have RS232, it has a usart which handles the NRZ protocol. This >> protocol is best known as being used by the RS232 interface. Therefore the >> protocol itself is commonly (but wrongly) referred to as "RS232" >> > >> > RS232 uses negative voltages as a symbolic "1" and positive voltages >> for "0". At the receiving side, the voltage must at least go higher than >> +3V for "0" and lower than -3V for "1". At the sending side, voltages from >> up to +15V and down to -15V are used. >> > >> > So, to answer your question in two simple sentences: RS232 is ok for >> the job. But RS232 is not what comes out of the controller. >> > >> > Greets, >> > Kiste >> > >> > >> > >> > >> > Am Dienstag, 20. April 2021, 21:56:34 MESZ hat majid ebru < >> [email protected]> Folgendes geschrieben: >> > >> > >> > >> > >> > >> > can i ask another question?? >> > >> > if it is 20 meter distance between PICs , i should use RS232 or SPI? >> > >> > so sorry and thanks a lot >> > >> > majid ebru در تاریخ سهشنبه ۲۰ آوریل ۲۰۲۱ ساعت >> > >> > -- >> > You received this message because you are subscribed to the Google >> Groups "jallib" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> an email to [email protected]. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/jallib/1697687282.4677348.1618979276333%40mail.yahoo.com. >> >> >> > >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "jallib" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/jallib/CAM%2Bj4qtaBjojssk_HHFK1M2dhhL9CNNf3mygd1F3nH0B5bck9A%40mail.gmail.com. >> >> >> >> -- You received this message because you are subscribed to the Google Groups "jallib" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/jallib/5c9f81de-8f9a-40cf-8802-b3a8493ad1a7n%40googlegroups.com.
