ESP8266 experiments

ESP8266.txt

I got cheap ESP8266.txt modules from China and was struggling to get them working electrically. It turns out they are very power hungry, in fact, when you use a serial adapter to power them, most likely they will crash the serial adapter due to their power draw. For this reason, I was not able to communicate with the device for a long time.

This setup works for me:
Solder VCC and CH_PD pin together (TODO: Check whether using a 1k pullup resistor changes the overall power consumption). Use a Prolific USB serial adapter to provide the 3.3V and GND, use another(!) serial adapter connected to the same USB hub (so that they share GND) to provide the RX and TX pins for the serial connection. This setup might not be the cleanest, but it was the quickest for me to get up and running.

According to my measurement with a cheap USB "Charger Doctor", the device draws 470 mA when hooked up to a Prolific serial adapter for providing the 3.3V.

My module had the following firmware pre-loaded:
[Vendor:www.ai-thinker.com Version:0.9.2.4]
I could communicate at 9600 baud with the device.

I am using the WiFiScan sketch to test. Uploading looks like this:

esptool v0.0.3a - (c) 2014 Ch. Klippel <ck@atelier-klippel.de>
	setting board to none
	setting baudrate from 115200 to 115200
	setting port from /dev/tty.usbserial to /dev/cu.SLAB_USBtoUART
	setting address from 0x00000000 to 0x00000000
	espcomm_upload_file
	stat /var/folders/h1/rsvk7j2568l73zfp2s80z9q80000gn/T/build71041253851688051.tmp/WiFiScan.cpp_00000.bin success
opening port /dev/cu.SLAB_USBtoUART at 115200
	tcgetattr
	tcsetattr
	serial open
opening bootloader
resetting board
trying to connect
	espcomm_cmd: sending command header
	espcomm_cmd: sending command payload
	serialport_receive_C0: 0C instead of C0
trying to connect
	espcomm_cmd: sending command header
	espcomm_cmd: sending command payload
	espcomm cmd: receiving 2 bytes of data
	espcomm_open
Uploading 32624 bytes from /var/folders/h1/rsvk7j2568l73zfp2s80z9q80000gn/T/build71041253851688051.tmp/WiFiScan.cpp_00000.bin to flash at 0x00000000
	erasing flash
	calculated erase delay: 596
	espcomm_cmd: sending command header
	espcomm_cmd: sending command payload
	espcomm cmd: receiving 2 bytes of data
	writing flash
................................
	setting address from 0x00000000 to 0x00040000
	espcomm_upload_file
	stat /var/folders/h1/rsvk7j2568l73zfp2s80z9q80000gn/T/build71041253851688051.tmp/WiFiScan.cpp_40000.bin success
	espcomm_open
Uploading 146132 bytes from /var/folders/h1/rsvk7j2568l73zfp2s80z9q80000gn/T/build71041253851688051.tmp/WiFiScan.cpp_40000.bin to flash at 0x00040000
	erasing flash
	calculated erase delay: 938
	espcomm_cmd: sending command header
	espcomm_cmd: sending command payload
	espcomm cmd: receiving 2 bytes of data
	writing flash
...............................................................................................................................................
starting app without reboot
	espcomm_cmd: sending command header
	espcomm_cmd: sending command payload
	espcomm cmd: receiving 2 bytes of data
closing bootloader

And sure enough, I do see the access points in my vicinity! :-) WORKS!

MAC address starts with 18:fe:34 which belongs to Espressif Inc.