Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

improve port expander handling #283

Merged
merged 4 commits into from
Dec 28, 2023
Merged

improve port expander handling #283

Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2ed25ac
suppress spurious interrupts from PE
r-schmidt Dec 26, 2023
afbd192
disable PORT_ExpanderISR until the input registers have been read
r-schmidt Dec 26, 2023
5fccbc3
improve access time to port expander
r-schmidt Dec 26, 2023
1404a67
debounce PE pins independently
r-schmidt Dec 26, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
113 changes: 74 additions & 39 deletions src/Port.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,22 +30,25 @@ void Port_Test(void);
#define PE_INTERRUPT_PIN_ENABLE
void IRAM_ATTR PORT_ExpanderISR(void);
bool Port_AllowReadFromPortExpander = false;
bool Port_AllowInitReadFromPortExpander = true;
#endif
#endif

void Port_Init(void) {
#ifdef PORT_EXPANDER_ENABLE
Port_Test();
Port_WriteInitMaskForOutputChannels();
Port_ExpanderHandler();
#endif

#ifdef PE_INTERRUPT_PIN_ENABLE
pinMode(PE_INTERRUPT_PIN, INPUT_PULLUP);
attachInterrupt(PE_INTERRUPT_PIN, PORT_ExpanderISR, FALLING);
// ISR gets enabled in Port_ExpanderHandler()
Log_Println(portExpanderInterruptEnabled, LOGLEVEL_NOTICE);
#endif

#ifdef PORT_EXPANDER_ENABLE
Port_AllowReadFromPortExpander = true;
Port_ExpanderHandler();
#endif
}

void Port_Cyclic(void) {
Expand Down Expand Up @@ -198,7 +201,7 @@ void Port_WriteInitMaskForOutputChannels(void) {
i2cBusTwo.write(0x02); // Pointer to first output-register
i2cBusTwo.endTransmission(false);
i2cBusTwo.requestFrom(expanderI2cAddress, static_cast<size_t>(portsToWrite), true); // ...and read the contents
if (i2cBusTwo.available()) {
if (i2cBusTwo.available() == portsToWrite) {
for (uint8_t i = 0; i < portsToWrite; i++) {
Port_ExpanderPortsOutputChannelStatus[i] = i2cBusTwo.read();
}
Expand Down Expand Up @@ -337,57 +340,82 @@ void Port_MakeSomeChannelsOutputForShutdown(void) {
// Reads input-registers from port-expander and writes output into global cache-array
// Datasheet: https://www.nxp.com/docs/en/data-sheet/PCA9555.pdf
void Port_ExpanderHandler(void) {
static bool verifyChangeOfInputRegister[2] = {false, false}; // Used to debounce once in case of register-change
static uint8_t inputRegisterBuffer[2];
static uint32_t inputChanged = 0; // Used to debounce once in case of register-change
static uint32_t inputPrev = 0;

// If interrupt-handling is active, only read port-expander's registers if interrupt was fired
// or the next time if there was a change
#ifdef PE_INTERRUPT_PIN_ENABLE
if (!Port_AllowReadFromPortExpander && !Port_AllowInitReadFromPortExpander && !verifyChangeOfInputRegister[0] && !verifyChangeOfInputRegister[1]) {
return;
} else if (Port_AllowInitReadFromPortExpander) {
Port_AllowInitReadFromPortExpander = false;
} else if (Port_AllowReadFromPortExpander || Port_AllowInitReadFromPortExpander) {
if (Port_AllowReadFromPortExpander) {
Port_AllowReadFromPortExpander = false;
}
else if (!inputChanged)
{
return;
}
#endif

for (uint8_t i = 0; i < 2; i++) {
i2cBusTwo.beginTransmission(expanderI2cAddress);
i2cBusTwo.write(0x00 + i); // Pointer to input-register...
uint8_t error = i2cBusTwo.endTransmission();
if (error != 0) {
Log_Printf(LOGLEVEL_ERROR, "Error in endTransmission(): %d", error);
return;
i2cBusTwo.beginTransmission(expanderI2cAddress);
i2cBusTwo.write(0x00); // Pointer to input-register...
uint8_t error = i2cBusTwo.endTransmission(false);
if (error != 0) {
Log_Printf(LOGLEVEL_ERROR, "Error in endTransmission(): %d", error);
i2cBusTwo.endTransmission(true);

#ifdef PE_INTERRUPT_PIN_ENABLE
Port_AllowReadFromPortExpander = true;
#endif

return;
}
i2cBusTwo.requestFrom(expanderI2cAddress, 2u); // ...and read its bytes

if (i2cBusTwo.available() == 2) {
uint32_t inputCurr = 0;
for (uint8_t i = 0; i < 2; i++) {
inputCurr |= i2cBusTwo.read() << 8*i; // Cache current readout
}
i2cBusTwo.requestFrom(expanderI2cAddress, 1u); // ...and read its byte

if (i2cBusTwo.available()) {
inputRegisterBuffer[i] = i2cBusTwo.read(); // Cache current readout
// Check if input-register changed. If so, don't use the value immediately
// but wait another cycle instead (=> rudimentary debounce).
// Added because there've been "ghost"-events occasionally with Arduino2 (https://forum.espuino.de/t/aktueller-stand-esp32-arduino-2/1389/55)
if (inputRegisterBuffer[i] != Port_ExpanderPortsInputChannelStatus[i] && millis() >= 10000 && !verifyChangeOfInputRegister[i]) {
verifyChangeOfInputRegister[i] = true;
// Serial.println("Verify set!");
} else {
verifyChangeOfInputRegister[i] = false;
Port_ExpanderPortsInputChannelStatus[i] = inputRegisterBuffer[i];
}

// Check if input-register changed. If so, don't use the changed bits immediately
// but wait another cycle instead (=> rudimentary debounce).
// Added because there've been "ghost"-events occasionally with Arduino2 (https://forum.espuino.de/t/aktueller-stand-esp32-arduino-2/1389/55)
inputChanged = inputPrev ^ inputCurr;

uint32_t inputStable = 0;
for (uint8_t i = 0; i < 2; i++) {
inputStable |= Port_ExpanderPortsInputChannelStatus[i] << 8*i;
}

// update bits that were stable since the last run
inputStable &= inputChanged;
inputStable |= (~inputChanged & inputCurr);

for (uint8_t i = 0; i < 2; i++) {
Port_ExpanderPortsInputChannelStatus[i] = (inputStable >> 8*i) & 0xff;
// Serial.printf("%u Debug: PE-Port: %u Status: %u\n", millis(), i, Port_ExpanderPortsInputChannelStatus[i]);
}

inputPrev = inputCurr;
}

#ifdef PE_INTERRUPT_PIN_ENABLE
// input is stable; go back to interrupt mode
if (!inputChanged) {
attachInterrupt(digitalPinToInterrupt(PE_INTERRUPT_PIN), PORT_ExpanderISR, ONLOW);
}
#endif
}

// Make sure ports are read finally at shutdown in order to clear any active IRQs that could cause re-wakeup immediately
void Port_Exit(void) {
Port_MakeSomeChannelsOutputForShutdown();
for (uint8_t i = 0; i < 2; i++) {
i2cBusTwo.beginTransmission(expanderI2cAddress);
i2cBusTwo.write(0x00 + i); // Pointer to input-register...
i2cBusTwo.endTransmission();
i2cBusTwo.requestFrom(expanderI2cAddress, 1u); // ...and read its byte
i2cBusTwo.beginTransmission(expanderI2cAddress);
i2cBusTwo.write(0x00); // Pointer to input-registers...
i2cBusTwo.endTransmission();
i2cBusTwo.requestFrom(expanderI2cAddress, 2u); // ...and read its bytes

if (i2cBusTwo.available()) {
if (i2cBusTwo.available() == 2) {
for (uint8_t i = 0; i < 2; i++) {
Port_ExpanderPortsInputChannelStatus[i] = i2cBusTwo.read();
}
}
Expand All @@ -406,7 +434,14 @@ void Port_Test(void) {

#ifdef PE_INTERRUPT_PIN_ENABLE
void IRAM_ATTR PORT_ExpanderISR(void) {
Port_AllowReadFromPortExpander = true;
// check if the interrupt pin is actually low and only if it is
// trigger the handler (there are a lot of false calls to this ISR
// where the interrupt pin isn't low...)
Port_AllowReadFromPortExpander = !digitalRead(PE_INTERRUPT_PIN);
// until the interrupt is handled we don't need any more ISR calls
if (Port_AllowReadFromPortExpander) {
detachInterrupt(digitalPinToInterrupt(PE_INTERRUPT_PIN));
}
}
#endif
#endif
Loading