18f252 oscillator

Started by Anonymous in Piclist15 years ago

hi all how do i configure the PIC for using the external clock using the CONFIG register.do we have a small sample to it. ...

hi all how do i configure the PIC for using the external clock using the CONFIG register.do we have a small sample to it. secondly can i generate a BAUD of 115200 for the USART using the 40mhz crystal .for this SPBRG shuld be set to 21.8 .does the openusart(); take the


USART on PIC18F4550

Started by sethmeisterG in Piclist10 years ago

Hi, I found out why my divisors weren't working -- the Fosc on the PIC18F4550 is 48MHz (when using USB in my configuration). Using...

Hi, I found out why my divisors weren't working -- the Fosc on the PIC18F4550 is 48MHz (when using USB in my configuration). Using 48MHz in all divisor calculations allowed me to get comm working perfectly. --S ------------------------------------


18F4331 and PWM

Started by Paul L in Piclist11 years ago 1 reply

Hi. Well, after getting my new PIC, it didn't take long to get it going! Was a little worried at first! I can now receive using USART and then...

Hi. Well, after getting my new PIC, it didn't take long to get it going! Was a little worried at first! I can now receive using USART and then using the values taken put that in the PWM unit and there i have a dimming LED! Beats having a DA and few Op-amps! My question is about the PWM maths. I have read the datasheet but can't figure out how to calculate the frequency of the PWM. Maybe caus...


Trouble with USART on PIC16F877A

Started by Alok Modak in Piclist10 years ago

Hi all, I am trying to interface the serial port of the PIC16F877A to communicate with the PC. But I am not able to do so. I have listed...

Hi all, I am trying to interface the serial port of the PIC16F877A to communicate with the PC. But I am not able to do so. I have listed below the connections that I have made. Any help will be of great help. Thanks, With Regards, Alok - Rx (Pin 26) of PIC16F877A connected to Pin9 (R2Out) of Max232. R2in (Pin8) of Max232 connected to TxD (Pin3) of DB9 female connector. -...


Pullup questions

Started by Vic Fraenckel in Piclist14 years ago 13 replies

I am designing my first PIC board. It will use a 16f876. I will use two PORTA pins and the USART pins RC6 and RC7 for serial comms....

I am designing my first PIC board. It will use a 16f876. I will use two PORTA pins and the USART pins RC6 and RC7 for serial comms. The board will be expanded later to use either I2C or SPI. The questions I have are: 1. Should ALL I/O pins be pulled up to +5V or should ONLY the un


USART electrical specifications information request

Started by Chris in Piclist13 years ago 7 replies

Does anybody have information about the TX pin in particular. I'm using a 16F628 to listen to a gps module's 1Hz data packet, strip out ...

Does anybody have information about the TX pin in particular. I'm using a 16F628 to listen to a gps module's 1Hz data packet, strip out the time information alone and then retransmit it at a slower baud rate over a short range radio link. It works, but I'm aware that if I wish to expand the system and tie another device to the pics TX pin things could go awr


16f877 usart

Started by German Enred in Piclist15 years ago

Hi: I'm making a program. it work across the UART (asyncronus mode), i need this write the 56 registers of n ASIC IC, then...

Hi: I'm making a program. it work across the UART (asyncronus mode), i need this write the 56 registers of n ASIC IC, then it can send a flow of bytes to RCIF, write address (PortD) and at the same time write the value of this address taked of RCIF to PORTB -config d


Cant return from interrupt (PIC16F877)

Started by farroos in Piclist15 years ago 3 replies

I have this small program that is supposed to do some routines when a USART recieve inturrept happens. I does the routines but...

I have this small program that is supposed to do some routines when a USART recieve inturrept happens. I does the routines but it doesnt return from inturrept to Main. I have attached a copy of the assemply code. Dont worry about the rotines, I'm sure they work. I dont know


Hi 16F877 USART

Started by Anonymous in Piclist15 years ago

Hi: I'm making a program. it work across the UART (asyncronus mode), i need this write the 56 registers of n ASIC IC, then it...

Hi: I'm making a program. it work across the UART (asyncronus mode), i need this write the 56 registers of n ASIC IC, then it can send a flow of bytes to RCIF, write address (PortD) and at the same time write the value of this address taked of RCIF to PORTB -config data-(in or


Help with usart receive

Started by Travis L. F Bailey in Piclist15 years ago 4 replies

Help, I am missing some obvious mistake. I just don't see it. I am using a pic18f452 chip and a max232 chip to communicate...

Help, I am missing some obvious mistake. I just don't see it. I am using a pic18f452 chip and a max232 chip to communicate to my laptop's serial port. I can send data from the pic to the pc, but, I can not receive data from hyperterm to the pic chip. I am also connect


RS-485 Communication & Pic16F628

Started by Roger_4U in Piclist11 years ago 4 replies

Hi All: I have a Pic16F628 chip which I want to be able to communicate with my PC via a RS-485 line. I want to use the USART on the chip and...

Hi All: I have a Pic16F628 chip which I want to be able to communicate with my PC via a RS-485 line. I want to use the USART on the chip and a DS75176 Transceiver in a Half Duplex setup, but my problem is with what to control the Read Enable or Transmit Enable pin on the DS75176? If anyone also has a simple schematic and code that they don't mind sharing I would be grateful. Regards ...


Having trouble with recieving data with PIC18F452 HW USART

Started by Travis L. F Bailey in Piclist15 years ago 2 replies

I am trying to get the serial to work on my pic18f452 chip. I can print data to hyperterm from pic with no problem. But, I can not...

I am trying to get the serial to work on my pic18f452 chip. I can print data to hyperterm from pic with no problem. But, I can not figure out how to get data from hypterterm to the pic. I am able to print, here is a sample of my output: First 2 RCSTA 144 TXSTA 160 First 3 RC


USART on the PIC18F4550: Weird Divisor Problem

Started by sethmeisterG in Piclist10 years ago

Hi, I've also been having weird problems with the divisor. I'm using a PIC18F4550 with a 20 MHz crystal. I've been trying to get ANY...

Hi, I've also been having weird problems with the divisor. I'm using a PIC18F4550 with a 20 MHz crystal. I've been trying to get ANY serial communications working (I'm using the PICDEM FS USB board). I finally broke down and wrote a program that tried every possible value for SPBRG (and the program outputs text and an ascii table at each discrete SPBRG value), and I set my terminal pr...


Frustrating problem with dsPic30F3012 ADC...

Started by demolitron in Piclist9 years ago

Hello, I just got my board built for my new dsPic project and I've run into a very puzzling problem with the ADC. If you all would be kind...

Hello, I just got my board built for my new dsPic project and I've run into a very puzzling problem with the ADC. If you all would be kind enough to take a look for me. I hope this isn't something simple and stupid I've missed... First, my environment: dsPic30F3012 @ 3.3V MPLAB 8.30 MPLAB C30 student edition version 3.12 compiler PICKIT 2 Debugger (DE Version = 1.40.3) USART level s...


16f877 sych and async comm question

Started by greerde in Piclist15 years ago

i'm starting on a project that requires async serial input and sync output. I just wanted to make sure the 16f877 can do both...

i'm starting on a project that requires async serial input and sync output. I just wanted to make sure the 16f877 can do both of these at the same time. I think i am going to use SPI (instead of I2C) for the sync output and USART for the async input. does this sound like a


18F6680 at 9600 USART garbles read data

Started by Dennis Clark in Piclist10 years ago 14 replies

Hi all, I've tried the Microchip forums and have an open support ticket but in two days I've heard nothing on this. I've got an...

Hi all, I've tried the Microchip forums and have an open support ticket but in two days I've heard nothing on this. I've got an interesting problem. I am running a 18F6680 at 40MHz. If I have the BRG set for 9600 baud and I will often get data that has bit 7 set when it shouldn't. The Tx data going out is fine, no odd bits set, but the Rx data has this issue if I am sending data fas...


Re: microchip's USART code..

Started by Ken Wilson in Piclist15 years ago 3 replies


framing error

Started by krishnap in Piclist15 years ago 4 replies

hi all i am using the pic 18f252.I am using the receive interrupt of the USART in which i just check for the incoming...

hi all i am using the pic 18f252.I am using the receive interrupt of the USART in which i just check for the incoming data and also check if there are any framing error