problems flashing sonoff basic r2 power v1

[micromys]

I do have a couple of problems flashing sonoff basic r2 power v1.0

a. It does not enter flashing mode (miniterm says bootmode(3,7) ) so I cannot flash it using usb->ttl (either from win10 or raspberry pi)

b. one of the devices is complete dead, can I recover it?

What am I doing wrong?

Thx for responding

[ThomasB]

What am I doing wrong?

A couple tips:
1. Your Sonoff has a ESP8265 with 1MB memory that uses DOUT. Be sure that you flash the correct firmware file. Hint: Use the latest Mega release that is compatible with your device.
2. Be sure to press and hold the push switch when you power it up. This enables the bootmode for UART flash.

- Thomas

[micromys]

thx for replying.

1. which firmware file?
2, I did hold the push button while powering up. Nothing seems to happen. (It all was correct on the old 8266 sonoff)

- Vincent

[TD-er]

Another thing you really should check is the 3V3 voltage level.
Some (most) USB to serial adapters are not capable of supplying enough power on the 3V3 line.
Either they increase the voltage even to 5V or it just sinks to a level where the ESP cannot work on.

For most Sonoff units you do need either an ESP8266 1M or ESP8285 build
So double check the used ESP chip on the board.
If you don't see any external flash chip, you probably have the ESP8285.

The only Sonoff's I know of with different sized flash are the Sonoff POW units. (these have 4M flash)