' Author:    Jim Gillespie
' Program:   FMxmtr1.bas
' Purpose:   Sets up NS73M module (SPARKFUN.COM) to transmit in stereo at
'            93.9 megahertz, 73 us pre-emphasis, 2 milliwatts transmit power and
'            200 millivolts audio input for 100% modulation.
' Date:      10-30-2007
' Version    1.22
' Compiler:  BASCOM-AVR IDE version 1.11.8.9 (MCS Electronics - MCSELEC.COM)
' Processor: ATMEL ATTINY13
'            ATTINY13 Fuses set for 4.8 megahertz internal RC oscillator &
'            brownout at 2.7 volts.
'            NS73M Module and ATTINY13 operate at 3.3 VDC.
'            NS73M module IIC pin is grounded.
' Legal      This code is free and intended for experimenter and DIY use only.
'            I assume no responsibility for improper use of this code.
'


$regfile = "attiny13.dat"               ' ATMEL ATTINY13 processor
$crystal = 4800000                      ' Internal RC osc. fuse set to 4.8 megahertz

Config Portb = Output                   ' Port B all outputs
Portb = 0                               ' Set all port B pins low

Ck Alias Portb.2                        ' Ck is SPI clock to module
Da Alias Portb.1                        ' Da is SPI data to module
La Alias Portb.0                        ' La is SPI latch pulse to module


Dim Regxmtr As Byte                     ' Module register number (4 bits)
Dim Datxmtr As Byte                     ' Module 8 bit data ( 8 bits )


Declare Sub Sendxmtr()                  ' Sends SPIish type info. to module

Waitms 50                               ' Wait some for power up settling


   Regxmtr = &H0E : Datxmtr = &H05      ' Software reset
   Gosub Sendxmtr
   Regxmtr = &H01 : Datxmtr = &HB4      ' Pilot on, forced subcarrier
   Gosub Sendxmtr
   Regxmtr = &H02 : Datxmtr = &H07      ' 2 mW power, Unlock detect on
   Gosub Sendxmtr
   Regxmtr = &H03 : Datxmtr = &HEA      ' Lower byte frequency  (93.9 megahertz)
   Gosub Sendxmtr                       ' NOTE: above value may require tweaking
   Regxmtr = &H04 : Datxmtr = &H2C      ' Upper byte frequency  (93.9 megahertz)
   Gosub Sendxmtr
   Regxmtr = &H08 : Datxmtr = &H1A      ' CEX = Band 2
   Gosub Sendxmtr
   Regxmtr = &H00 : Datxmtr = &HA1      ' Pwr on, 200 mV audio for 100% modulation
   Gosub Sendxmtr                       ' NOTE: 75 uS pre-emphasis (North America)
   Regxmtr = &H0E : Datxmtr = &H05      ' Software reset
   Gosub Sendxmtr
   Regxmtr = &H06 : Datxmtr = &H1E      ' Set internal charge pumps
   Gosub Sendxmtr
   Mcucr = &H38                         ' Prepare to sleep MCU
   sleep                                ' Sleeps processor
Do : Loop                               ' Just in case it wakes up



Sub Sendxmtr()                          ' Sends SPIish data to module ( 12 bits)
   Shiftout Da , Ck , Regxmtr , 2 , 4 , 1       ' Send 4 bits of register number
   Shiftout Da , Ck , Datxmtr , 2 , 8 , 1       ' Send 8 bits of data
   Waitus 1                             ' Short wait
   Set La                               ' Set latch output
   Waitus 4                             ' Short wait
   Reset La                             ' Reset latch output
   Return
End Sub

End