rfPIC Serin problem

[medusa2584]

thank you very much for the reply..

i have one more question..im testing the rfPIC development kit right now with the demo program..we are trying to test the rf12F675 by using oscilloscope by conneting the probe to the pin output which is pin GP5 and GP0. however, we see no signals output from the transmitter except the analog voltage value 1.29 mv which i think comes from the power supply.

any suggestion how to test it? we have checked the connection circuit many times..but it still give us the same result

[Bruce]

You must have a different rfPIC development kit than the one I have. GP0 on mine connects
to POT0. GP5 to the RFENA pin?

Here are the pin definitions in the Microchip demo tx code example;

#define POT0 GPIO, 0 ; (Analog Input) Potentiometer GP0
#define POT1 GPIO, 1 ; (Analog Input) Potentiometer GP1
#define TXD GPIO, 2 ; (Output) Transmit Data
#define PB3 GPIO, 3 ; (Input Only) Push button switch GP3
#define PB4 GPIO, 4 ; (Input) Push button switch GP4
#define RFENA GPIO, 5 ; (Output) RF Enable

I also have a full schematic in .PDF format on my CD that verifies this.

Have you tried placing the scope on GP2?

[medusa2584]

yup we did try..but we dont get the expected signal..

am i right if im expecting a modulated signal came out from the output channel? so i should be able to see an analog modulated signal with ASK. but, we only see a digital signal 0 1 which i think comes from the power supply that we used.

im sorry..i gave the wrong information. we are using the same develoment kit as yours

thank you

[Bruce]

we only see a digital signal 0 1

You should be seeing a digital signal if you're placing a scope probe on GP2. This is a digital
I/O-pin connected to pin #14 DATAask on your tx board. That's your outbound data being
used to control the PA.

Read the data sheet, section 9.4, ASK Modulation and you'll see why an I/O-pin
would be connected to pin #14.

You can find a modulated signal on the antenna output, but you'll be loading it with your
scope probe.

[onepiece]

Hi
I would like to test whether my rfpic12f675 an rfrxd0420 works according to the demo for the development kit. The part for LED indicators on the Pickit Flash 1, it says that when my GP buttons on transmitter are pressed, LED will be lite up. Does that mean that we can just verify this through the dev kit? The LED on my board sometimes toggle when I press the switches, and I thought I should have got a 7 LEDs to light up.
I'm confused at the part where I need to use PIC16f676 for the rxrfd420, do I need to connect the pins RA5 to RC 2 to the PIC itself? Can anyone help me please.

[Bruce]

Read the rfPIC Dev Kit Quick Start Quide. It has blow-by-blow instructions. The link above
will take you directly to the page where you can download this if you don't already have it.

[medusa2584]

yes..we finally manage to test the rfkit and it works..

now its the time for me to alter the code..the transmitter right now required no external input except from the switch to operate. we planned to replace the gp4 with input from sensor and the input is digital . however there are some part of the demo program that i dont understand the purpose which i pasted below.

under part "fill in transmission buffer" , why they purposely inserted the random number into the buffer register?and then will be ignored by receiver ? and how the receiver is going to ignore it?

and since the input for this demo is analog signal, they have used the converter and have the result stored in register ADRESH and ADRESL. so as for me who has a digital input, i should be able to read straight from the gpio port , but im not sure how is the command since im only read from one bit of register.



and this command means the input data being read and stored in temp register?

the part of demo program that im confused

;----------------------------------
; fill in transmission buffer
;----------------------------------

XMIT

bsf RFENA ; Enable Transmitter

movlw 0x73 ; send Serial number
movwf CSR0

movfw FuncBits ; send Function Bits
movwf CSR1

; send 16-bit Counter
;
; send analog value (this is modified from the fixed
; KeeLoq(r) protocol; these two fields are normally
; used for 16-bit counter value)

bsf STATUS, RP0 ; ----- Select Bank 1 -----
movfw ADRESL ; ADRESL Result
bcf STATUS, RP0 ; ----- Select Bank 0 -----
movwf CSR2

movfw ADRESH ; ADRESH Result
movwf CSR3

movlw 0x56 ; send 32-bit serial number 1 (ignored by receiver)
movwf CSR4

movlw 0x34
movwf CSR5

movlw 0x12
movwf CSR6

movlw 0x20
movwf CSR7

movlw 0x55 ; send Flags
movwf CSR8

[medusa2584]

thank you very much for the reply..

i have one more question..im testing the rfPIC development kit right now with the demo program..we are trying to test the rf12F675 by using oscilloscope by conneting the probe to the pin output which is pin GP5 and GP0. however, we see no signals output from the transmitter except the analog voltage value 1.29 mv which i think comes from the power supply.

any suggestion how to test it? we have checked the connection circuit many times..but it still give us the same result

does anyone know why we have to times it by 32? i have looked at the datasheet, but it does not state the reason anywhere.