path: root/software/hhd70dongle/c1101lib.c

/*
 *
 *  mur.sat
 *
 *  Somewhen in the year 2012, mur.at will have a nano satellite launched
 *  into a low earth orbit (310 km above the surface of our planet). The
 *  satellite itself is a TubeSat personal satellite kit, developed and
 *  launched by interorbital systems. mur.sat is a joint venture of mur.at,
 *  ESC im Labor and realraum.
 *
 *  Please visit the project hompage at sat.mur.at for further information.
 *
 *
 *  Copyright (C) 2012 Bernhard Tittelbach <xro@realraum.at>
 *
 *  This file is part of mur.sat.
 *
 *  mur.sat is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  mur.sat is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with mur.sat. If not, see <http://www.gnu.org/licenses/>.
 *
 */
#include <avr/io.h>
#include <util/delay.h>

#include "c1101lib.h"
#include "spi.h"
#include "usb_rawhid.h"
#include "util.h"

/**** Helper Functions ****/

#define SPIC1101_MAX_WAIT 21

int16_t spi_c1101_write_byte_ok_get_status(char data)
{
    //~ uint8_t debug_sb[6];
    char sb;
    unsigned int attempts = 0;
    do
    {
        sb = spi_exchange_byte(data);
        //Note: content of returned StatusByte is actually context depenedant on sent command
        //            i.e. we won't get Fifo Byte count or overflow status on normal command and so on
        //            e.g. we only get TX Fifo Free Byte count while writing to TX Fifo
        //            thus it makes sense to only check for CHIP_RDY here
        //~ usb_rawhid_send((uint8_t*)"spi byte exchanged ",255);
        //~ debug_sprint_int16hex(debug_sb, sb);
        //~ usb_rawhid_send(debug_sb,255);
        if (attempts++ > SPIC1101_MAX_WAIT)
            return -1;
    } while ( SPIC1101_SB_CHIP_NOT_RDY(sb) );
    return sb;
}

// note addresses range from 0x00 to 0x2F for normal registers and 0xF0 to 0xFD for special status registers
int16_t spi_c1101_read_register(char address)
{
    char rbyte;
    if (address < 0x30)
        address |= 0x80;
    else
        address |= 0xC0;
    spi_cs_enable();
    spi_c1101_wait_chip_rdy();
    if (spi_c1101_write_byte_ok_get_status(address) < 0)
        return -1;
    _delay_ms(10); //FIXME: propably don't need this
    rbyte = spi_read_byte();
    spi_cs_disable();
    return rbyte;
}

// note addresses range from 0x00 to 0x2F for normal registers
int16_t spi_c1101_write_register(char address, char byte)
{
    spi_cs_enable();
    spi_c1101_wait_chip_rdy();
    if (spi_c1101_write_byte_ok_get_status(address & 0x2F) < 0)
        return -1;
    _delay_ms(2);
    if (spi_c1101_write_byte_ok_get_status(byte) < 0)
        return -1;    
    spi_cs_disable();
    return 1;
}

// note addresses range from 0x30 to 0x3D for command strobes
int16_t spi_c1101_strobe_command(char address)
{
    if (spi_c1101_write_byte_ok_get_status(address) < 0)
        return -1;
    return 1;
}

void spi_c1101_dump_registers_to_usb(void)
{
    int c = 0;
    uint8_t debug_sb[6];
    spi_cs_enable();
    spi_c1101_wait_chip_rdy();
    if (spi_c1101_write_byte_ok_get_status(0xC0) < 0)
        return;
    usb_rawhid_send((uint8_t*)"dump all 46 registers:",255);
    for (c=0; c<47; c++)
    {
        debug_sprint_int16hex(debug_sb, spi_read_byte());
        usb_rawhid_send(debug_sb,255);
    }
    spi_cs_disable();
}

//note: currently this function reads at most 15 bytes
int spi_c1101_read_rxfifo(int leave_num_bytes, char *buffer, int maxlen)
{
    int16_t sb;
    int num_read = 0;
    int num_fifo_available = 0;
    spi_cs_enable();
    spi_c1101_wait_chip_rdy();
    sb = spi_c1101_write_byte_ok_get_status(SPIC1101_ADDR_FIFO_READ_BURST);
    if (sb < 0)
        return -1;
    num_fifo_available = SPIC1101_SB_FIFO_BYTES_AVAILABLE((char)sb);
    //note if num_fifo_available  == 15 then 15 or more bytes are available
    //FIXTHIS
    while (maxlen-- && num_fifo_available - num_read <= leave_num_bytes)
    {
        //hope this works !!
        buffer[num_read++] = spi_read_byte();
    }
    spi_cs_disable();
    return num_read;
}

//note: always check if num_written returned == len given
//note: currently this function writes at most 15 bytes
int spi_c1101_write_txfifo(char *buffer, int len)
{
    char sb;
    int num_written = 0;
    int num_fifo_available = 0;
    spi_cs_enable();
    spi_c1101_wait_chip_rdy();
    sb = spi_c1101_write_byte_ok_get_status(SPIC1101_ADDR_FIFO_WRITE_BURST);
    if (sb < 0)
        return -1;
    num_fifo_available = SPIC1101_SB_FIFO_BYTES_AVAILABLE((char)sb);
    //note if num_fifo_available  == 15 then 15 or more bytes are available
    //FIXTHIS
    if (num_fifo_available < len)
        len = num_fifo_available;
    while (len--)
    {
        //hope this works !!
        spi_write_byte(buffer[num_written++]);
    }
    spi_cs_disable();
    return num_written;
}



/**** External Functions ****/

void c1101_init(void)
{
    //reset C1101
    spi_c1101_strobe_command(SPIC1101_ADDR_SRES);
    _delay_ms(100);
    //flush FIFOs
    spi_c1101_strobe_command(SPIC1101_ADDR_SFRX);
    spi_c1101_strobe_command(SPIC1101_ADDR_SFTX);
    //dump current default values to usb
    spi_c1101_dump_registers_to_usb();
    //enable analog temperature sensor on GDO0
    spi_c1101_write_register(SPIC1101_ADDR_IOCFG0, 0x80);
    // note: for now: assume f_xosc to be 26 Mhz
    // for ~433.125 Mhz -> freq = 1091741, freq_offset = 0
    c1101_setFrequency(1091741,0,15);
}

// freq:            desired_carrier_freq [Hz] *2^16 / f_XOSC
// freq_offset:     desired frequency offset [Hz] *2^14 / f_XOSC
// if_freq:         desired intermidiate rx frequency [Hz] *2^10 / f_XOSC
void c1101_setFrequency(uint32_t freq, uint8_t freq_offset, uint8_t if_freq)
{
    //make sure we are in idle mode
    char sb=0;
    do
    {
        sb = c1101_getStatus();
    } while (! (SPIC1101_SB_IDLE(sb)));
    //programm frequency
    usb_rawhid_send((uint8_t*)"setting frequency",255);
    spi_c1101_write_register(SPIC1101_ADDR_FREQ0, freq & 0xFF);
    spi_c1101_write_register(SPIC1101_ADDR_FREQ1, (freq >> 8) & 0xFF);
    spi_c1101_write_register(SPIC1101_ADDR_FREQ2, (freq >> 16) & 0x3F);

    //set frequency offset
    spi_c1101_write_register(SPIC1101_ADDR_FSCTRL0, freq_offset);
    //spi_c1101_write_register(SPIC1101_ADDR_FSCTRL1, if_freq & 0x1F);
    
    //set channel 0
    spi_c1101_write_register(SPIC1101_ADDR_CHANNR, 0);
}

char c1101_getVersion(void)
{
    return spi_c1101_read_register(SPIC1101_ADDR_VERSION);
}

char c1101_getPartNum(void)
{
    return spi_c1101_read_register(SPIC1101_ADDR_PARTNUM);
}

uint16_t c1101_measureTemp(void)
{
    uint16_t temp;
    char ptest_value=0x7F;
    ptest_value = spi_c1101_read_register(SPIC1101_ADDR_PTEST);
    spi_c1101_write_register(SPIC1101_ADDR_PTEST, 0xBF);
    _delay_ms(5);
    temp = adc_read(ADCMUX_INTERNALTEMP);
    spi_c1101_write_register(SPIC1101_ADDR_PTEST, ptest_value);
    return temp;
}

void c1101_handleStatusByte(char sb)
{
    //on RXFifo Overflow, Flush RX Fifo
    if (SPIC1101_SB_RXFIFO_OVERFLOW(sb))
    {
        spi_c1101_strobe_command(SPIC1101_ADDR_SFRX);
        usb_rawhid_send((uint8_t*)"RX fifo flushed",255);
    }
    //on TXFifo Overflow, Flush TX Fifo
    if (SPIC1101_SB_TXFIFO_OVERFLOW(sb))
    {
        spi_c1101_strobe_command(SPIC1101_ADDR_SFTX);
        usb_rawhid_send((uint8_t*)"TX fifo flushed",255);
    }
}

char c1101_getStatus(void)
{
    char sb=0;
    spi_cs_enable();
    spi_c1101_wait_chip_rdy();    
    sb = spi_c1101_write_byte_ok_get_status(SPIC1101_ADDR_SNOP);
    spi_cs_disable();
    //debug start
    uint8_t debug_sb[6];
    usb_rawhid_send((uint8_t*)"c1101 status:",255);
    debug_sprint_int16hex(debug_sb, sb);
    usb_rawhid_send(debug_sb,255);
    //debug end
    c1101_handleStatusByte(sb);
    return sb;
}


//max len: 64 bytes
void c1101_writeTXFifo(char *buffer, unsigned int len)
{
    //check TXBYTES.NUM_TXBYTES
    // never write more bytes than avaiblabe or doom ensues
    
    
}

//max returned: 64 bytes
int c1101_readRXFifo(char *buffer)
{
    //check RXBYTES.NUM_RXBYTES
    // never read more bytes than avaiblabe or we will read garbage
    
    //note: if RX transmission fills fifo buffer at exact same time as last RX Fifo Bit is read via SPI, Fifo Pointer will not be properly updated 
    //            and last read byte will be duplicated.
    // thus: don't last avialable FIFO Bytes unless we can be sure that it will be the last byte of a packet and we can be sure that a following duplicated byte is actually an Fifo duplication and not an actually recieved byte !
    
    return 0;
}