Problem getting started with ESP32-WROOM-02

[ELESSUK]

I am having problems getting started with the ESP32-WROOM-02.

I am using it in this configuration:



The TXD and RXD lines are connected to a USB-TTL converter (FT232R based IC). This then connects to my PC which is running Ubuntu 17.10. I am using minicom (linux terminal emulator) to connect to /dev/ttyUSB0.
I am trying to communicate with the ESP32 in order to communicate AT commands. When my baud rate (minicom) is set to 115200 8N1, I get a garbled message followed by ready when I power up the device. When I change the baud rate to 74880, I get the following:

ets Jan 8 2013,rst cause:1, boot mode:(3,7)



load 0x40100000, len 2408, room 16

tail 8

chksum 0xe5

load 0x3ffe8000, len 776, room 0

tail 8

chksum 0x84

load 0x3ffe8310, len 632, room 0

tail 8

chksum 0xd8

csum 0xd8



2nd boot version : 1.6

SPI Speed : 40MHz

SPI Mode : QIO

SPI Flash Size & Map: 16Mbit(512KB+512KB)

jump to run user1 @ 1000



rf cal sector: 507

rf[112] : 00

rf[113] : 00

rf[114] : 01



SDK ver: 2.0.0(5a875ba) compiled @ Aug 9 2016 15:12:27

phy ver: 1055, pp ver: 10.2



�@j��

It seems that the ESP32-WROOM-02 is initially booting using 74880, then changes to 115200.

When I power up using 115200, any characters entered in minicom are echoed back but are not acted upon - i.e. AT (then return).
I've checked that both the TXD and RXD lines are clean and are nice and the level transition are nice and square.

I have also tried flashing the ESP32-WROOM-02 using the hello_world example in esp_idf. This successfully compiles, but then times out with the following message:

Flashing binaries to serial port /dev/ttyUSB0 (app at offset 0x10000)...
esptool.py v2.1
Connecting........_____....._____....._____....._____....._____....._____....._____....._____....._____....._____

A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header

Any suggestions as to what I am doing wrong?

Thanks
Eless

[ESP_Sprite]

An ESP-WROOM-02 has an ESP8266 processor instead, not an ESP32. You can program it with one of the two ESP8266 SDKs, but esp-idf will not produce a working binary for it.