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All tested compilers & make build now have proper timing for tx switching (gcc 4.9.3, O0, Os, O3, gcc 6.3. O0, O3)

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This commit is contained in:
danilo 2017-04-02 03:09:30 +02:00
parent 02ee23b684
commit 70457f269e
6 changed files with 104 additions and 66 deletions
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83
IO.cpp
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@ -29,9 +29,11 @@ uint32_t m_frequency_rx;
uint32_t m_frequency_tx;
uint8_t m_power;
extern volatile bool sle_request;
// TODO: move to IO class as members
volatile bool totx_request = false;
volatile bool torx_request = false;
bool volatile even = true;
volatile bool even = true;
static uint32_t last_clk = 2;
CIO::CIO():
m_started(false),
@ -101,8 +103,7 @@ void CIO::process()
// Switch off the transmitter if needed
if (m_txBuffer.getData() == 0U && m_tx) {
//while(CLK_pin()==0) { asm volatile ("nop"); }
//while(CLK_pin()) { asm volatile ("nop"); }
setRX(false);
torx_request = true;
while(torx_request) { asm volatile ("nop"); }
}
@ -158,13 +159,33 @@ void CIO::interrupt()
if (!m_started)
return;
uint8_t clk = CLK_pin();
uint8_t clk = CLK_pin();
// this is to prevent activation by spurious interrupts
// which seem to happen if you send out an control word
// needs investigation
// this workaround will fail if only rising or falling edge
// is used to trigger the interrupt !!!!
// TODO: figure out why sending the control word seems to issue interrupts
// possibly this is a design problem of the RF7021 board or too long wires
// on the breadboard build
// but normally this will not hurt too much
if (clk == last_clk) {
return;
} else {
last_clk = clk;
}
// we set the TX bit at TXD low, sampling of ADF7021 happens at rising clock
if (m_tx && clk == 0) {
m_txBuffer.get(bit);
even = !even;
// use this for tracking issues
// P25_pin(even);
#if defined(BIDIR_DATA_PIN)
if(bit)
RXD_pin_write(HIGH);
@ -177,21 +198,26 @@ void CIO::interrupt()
TXD_pin(LOW);
#endif
// wait a brief period before raising SLE
if (sle_request == true) {
#if 1
asm volatile("mov r8, r8 \n\t"
"mov r8, r8 \n\t"
"mov r8, r8 \n\t"
);
#endif
if (totx_request == true) {
asm volatile("nop \n\t"
"nop \n\t"
"nop \n\t"
);
// SLE Pulse, should be moved out of here into class method
// according to datasheet in 4FSK we have to deliver this before 1/4 tbit == 26uS
SLE_pin(HIGH);
asm volatile("mov r8, r8 \n\t"
"mov r8, r8 \n\t"
"mov r8, r8 \n\t"
);
asm volatile("nop \n\t"
"nop \n\t"
"nop \n\t"
);
SLE_pin(LOW);
SDATA_pin(LOW);
sle_request = false;
// now do housekeeping
totx_request = false;
// first tranmittted bit is always the odd bit
even = false;
}
}
// we sample the RX bit at rising TXD clock edge, so TXD must be 1 and we are not in tx mode
@ -203,10 +229,26 @@ void CIO::interrupt()
m_rxBuffer.put(bit);
}
if (torx_request == true && even == true && m_tx && clk == 0) {
setRX();
if (torx_request == true && even == false && m_tx && clk == 0) {
// that is absolutely crucial in 4FSK, see datasheet:
// enable sle after 1/4 tBit == 26uS when sending MSB (even == false) and clock is low
delay_us(26);
// SLE Pulse, should be moved out of here into class method
SLE_pin(HIGH);
asm volatile("nop \n\t"
"nop \n\t"
"nop \n\t"
);
SLE_pin(LOW);
SDATA_pin(LOW);
// now do housekeeping
m_tx = false;
torx_request = false;
//last tranmittted bit is always the even bit
// since the current bit is a transitional "don't care" bit, never transmitted
even = true;
}
@ -274,6 +316,9 @@ void CIO::write(uint8_t* data, uint16_t length)
// Switch the transmitter on if needed
if (!m_tx) {
setTX();
totx_request = true;
// not sure if needed, would be better if handled in interrupt (like torx_request)
// or move into setTX()
while(CLK_pin());
m_tx = true;
}