I was hoping someone could point me in the right direction (or preferably tell me what simple thing I’ve overlooked).
I’m trying to use the Freetronics USB to Serial adapter + the Sonoff Programming adapter (from this website) to flash a couple of Sonoff SV’s. I’ve used this equipment before to flash two other Sonoff SV’s with Tasmota firmware without issue.
However, today I cannot get esptool to connect to the Sonoff, instead receiving the error “Failed to connect to ESP8266: Timed out waiting for packet header”
The Sonoff appears to be in programming mode (no LED flashing), but while esptool is trying to connect, the Serial to USB adapter RX LED flashes (and the blue voltage led is on) but no
I have tried:
- Different Sonoff SV’s (one straight out of the packet)
- Different computers (mac, windows)
- Different USB cables.
- On a breadboard wiring RX to RX and TX to TX instead of RX/TX TX/RX.
- Powering the sonoff from external power and only connecting RX + TX to the sonoff programming adapter.
- Checked to make sure there is continuity between the USB/Serial + sonoff programming adapter for all pins.
- Checked voltage of 3.3V is being provided to the Sonoff.
The USB/Serial adapter is being picked up by my computers and powering the Sonoff, so it doesn’t seem faulty, but equally I cannot think of anything else to swap out/eliminate.
Thanks in advance