github/esphome
2
0
Fork 0
mirror of https://github.com/esphome/esphome.git synced 2026-10-21 21:36:14 +00:00
Code Issues Packages Projects Releases Wiki Activity

Improve bus busy behavior, fix its timing

Browse Source
This commit is contained in:
Jos van Eijndhoven
2026-05-18 20:16:06 +02:00
parent dfe056f2ea
commit 4f2bfd616a
1 changed files with 4 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files
esphome/components/hdmi_cec/hdmi_cec.cpp
+4 -3
View File
@@ -28,7 +28,7 @@ static constexpr uint32_t LOW_BIT_US = 1500;
static constexpr uint32_t SIGNAL_FREE_TIME_AFTER_RECEIVE = (TOTAL_BIT_US * 5);
static constexpr uint32_t SIGNAL_FREE_TIME_AFTER_XMIT_FAIL = (TOTAL_BIT_US * 3);
static constexpr uint32_t SIGNAL_FREE_TIME_AFTER_XMIT_SUCCESS = (TOTAL_BIT_US * 7);
static constexpr uint8_t MAX_ATTEMPTS = 5;
static constexpr uint8_t MAX_ATTEMPTS = 8; // CEC says 5, but we also count 'bus busy' occurences
// constants used for this implementation:
static const char *const TAG = "hdmi_cec";
@@ -375,7 +375,8 @@ void CECTransmit::transmit_message() {
// pin to detect a bus collision and allow early termination of the frame transmit
if (!send_start_bit_() || !transmit_my_address_(frame->initiator_addr())) {
// sending these first bits caused a bus-collision with another initiator.
// further transmission is stopped immediatly, as the other initiator might not see the collision,
// further transmission is stopped immediatly, as the other initiator might not see the collision
confirm_received_us_ = micros(); // this would otherwise be set after seeing the (first) full byte
required_idle_period_ = SIGNAL_FREE_TIME_AFTER_XMIT_FAIL;
transmit_state_ = TransmitState::IDLE;
return;
@@ -392,7 +393,7 @@ void CECTransmit::transmit_message() {
bool CECTransmit::transmit_my_address_(const uint8_t initiator_addr) {
// My (initiator) address is in the 4 MSB bits of the header byte (CEC transfers MSB first)
bool ok = true;
for (int i = 3; i >= 0; i--) {
for (int i = 3; i >= 0 && ok; i--) {
bool bit_value = ((initiator_addr >> i) & 0x1);
if (bit_value) {
ok &= send_high_and_test_();