n the past few months ESP8266 has created a real revolution in the IoT space. I’m using it in a project that will hit Indiegogo in a month or so and you, of course will support me ☺ During the development process I’ve learned a lot and I want to share a part of it. Let’s build cheap open WiFi finder together!
Software
NodeMcu firmware https://github.com/nodemcu/nodemcu-firmware
ESP8266 flasher http://www.xess.com/blog/esp8266-reflash/
ESPlorer http://esp8266.ru/esplorer/
Actual scripts https://github.com/kstevica/ESP8266-WiFi-Finder
Hardware
ESP8266 01 variant http://www.ebay.com/itm/ESP8266-Serial-WIFI-Wireless-Transceiver-Module-Send-Receive-LWIP-AP-STA-A-/201205524305?pt=LH_DefaultDomain_0&hash=item2ed8c8a751
USB to TTL serial converter http://www.ebay.com/itm/USB-To-RS232-TTL-PL2303HX-Auto-Converter-Module-Converter-Adapter-For-arduino-/180953299346?pt=LH_DefaultDomain_0&hash=item2a21a83992
Logic level converter 5V to 3.3V http://www.banggood.com/Logic-Level-Converter-Bi-Directional-IIC-4-Way-Level-Conversion-Module-p-938774.html
Two coin batteries CR2450 http://www.ebay.com/itm/5-x-CR2450-2450-DL2450-ECR2450-5029LC-Cell-Button-Battery-/221674539224?pt=AU_Electronics_Batteries_Chargers&hash=item339cd508d8
Soldering equipment (you can use protoboard to avoid soldering)
Few wires http://www.banggood.com/buy/Dupont.html
Tape
Let’s start!
Download ESP8266 flasher and ESPlorer. Connect USB to TTL adapter with ESP8266 using logic level converter:
USB 5V to LLC high voltage
USB 3.3V to LLC low voltage
USB GND to LLC high GND
LLC high GND to LLC low GND
USB TX to LLC HV1
USB RX to LLC HV2
ESP8266 VCC to LLC low voltage
ESP8266 GND to LLC low GND
ESP8266 TX to LLC LV2
ESP8266 RX to LLC LV1
ESP8266 CH_PD to LLC low voltage
And you’re almost ready to go ☺ Connect ESP8266 GPIO0 to LLC low GND to put ESP8266 into firmware flash mode and restart it, simple disconnect VCC pin. Start ESP8266 flasher, select firmware file from nodemcu folder (pre_build/latest), enter COM port of your USB to TTL module and start flashing. If everything is ok, you should see the message “Erasing flash”. If not, check the wiring and try again. After successful flash, disconnect the GPIO0 pin and restart the ESP8266 module. Congratulations, you’re ready to upload LUA sketches on your ESP8266!
For more detail: How to build an open WiFi finder using ESP8266 and two coin batteries
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