Description
The problem
I am using remote_transmitter.transmit_rc_switch_raw to encode a protocol without a well-defined sync.
So I set:
sync: [0, 0]
On an esp8266 (e.g. d1 mini) this works but on an esp32 (e.g., devkit or tdisplay) it FAILS to generate ANY signal when sync.
This is at best an inconsistency in behavior between platforms and at worst a bug.
The failure is SILENT without any error or debug messages either at compile time or run time.
Note that:
[0, 0], [0, 1], and [1,0] all FAIL.
But even a sync as short as [1, 1] SUCCEEDS
Is there any way to get no sync on an esp32?
That is a very valid use case when one just wants to generate a pulse train without a sync.
It should be easy to fix.
But if for whatever reason you choose not to, it should at least be documented in the docs and should issue an error or warning either at compile or run-time. It is after all not at all obvious that [0, 0], [0,1], [1, 0] work on some platforms but fail the entire routing silently on others.
Which version of ESPHome has the issue?
2025.6.2
What type of installation are you using?
Home Assistant Add-on
Which version of Home Assistant has the issue?
2025.6.3
What platform are you using?
ESP32
Board
esp32 devkit, esp32 tdisplay, d1 mini
Component causing the issue
remote_transmitter
YAML Config
substitutions:
tx_pin: "18" # "18" for esp32; "5" for d1 mini
globals:
- id: tx_pin
type: int
initial_value: "${tx_pin}"
esphome:
name: test_remote
min_version: 2025.4.0
esp32:
board: esp32dev
framework:
type: arduino
# esp8266:
# board: d1_mini
ota:
- platform: esphome
password: !secret ota_password
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
api:
encryption:
key: !secret api_key
reboot_timeout: 0s
logger:
remote_transmitter:
pin: ${tx_pin}
carrier_duty_percent: 100%
interval:
- interval: 1s
then:
- remote_transmitter.transmit_rc_switch_raw:
code: '1111111111111111111111111111111111111111111111111111111111111111' # 64 pulses
protocol:
pulse_length: 1000 # 20ms high + low pulse
one: [1, 1]
# sync: [1, 1]
sync: [0, 0]
- lambda: |-
ESP_LOGW("TRANSMIT", "Pulse Transmitted to GPIO %d" , id(tx_pin));Anything in the logs that might be useful for us?
NOTHING IN LOGS - FAILS SILENTLYAdditional information
No response