#Coolterm esp8266 serial
#Coolterm esp8266 update
#Coolterm esp8266 software

#Coolterm esp8266 serial

I recommend first configuring the module for a lower baud rate, 9600 or less, utilizing a FT232R or similar USB to Serial bridge chip BOB (Breakout Board) or cable.

#Coolterm esp8266 software

The spurious characters lead me to suspect, the main issue you face at the moment is attempting to communicate with the module through a softUART, Arduino's Software Serial Library. As there are valid text intermixed with spurious characters, the current baud rate appears to be correct.

#Coolterm esp8266 update

The first step to update the flash firmware is to pull down the GPIO0 pin by attaching it GND (ground) with a pull down resistor and then resetting the module by momentarily pull the RST pin to GND, which put the module into its bootloader mode/state.Īfter examining the screen capture you've posted above, it appears the module is loaded with the AI-Thinker AT Firmware v0.9.5.0 or v0.9.5.2, their latest release of firmware. Also, the CH_PD (chip enable) must be pulled high with a pull up resistor attached to Vcc and remain so, for normal module function. However, it must not be pull low on power up or reset or the module will enter it's bootloader mode. Try properly configuring CH_PD and GPIO0 and connecting at 9600 baud.Īfter experimenting around with the same or similar ESP8266 modules and consulting with Alex, it appears the GPIO0 pin has an internal pull up resistor, so it may be left unconnected. Also, when using a softUART like that of the Software Serial library of the Arduino, you should typically keep the baud rates low, 9600 or lower. If both CH_PD and GPIO0 are not pull high, the device enters its bootloader or flash mode which utilizes an uncommon baud rate, which might explain all the spurious characters you've been seeing. If I remember correctly, both CH_PD and GPIO0 should be pull high for the device to boot the firmware loaded in flash, of course VCC and GND need to be properly connected as well. Try properly configuring CH_PD and GPIO0 and connecting at 9600 baud. If both CH_PD and GPIO0 are not pulled high, the device enters its bootloader or flash mode which utilizes an uncommon baud rate, which might explain all the spurious characters you've been seeing. If I remember correctly, both CH_PD and GPIO0 should be pulled high for the device to boot the firmware loaded in flash, of course VCC and GND need to be properly connected as well.

You may want to consider upgrading the current firmware to the latest revision: What version of the firmware is currently loaded into the device? I do know there are several versions of the AT Command set firmware, which have successively improved the serial interface connectivity. While I've had success programming the 32-bit 80MHz ARM core directly using the Arduino IDE and the ESP8266 add on SDK and utilizing the device as a standalone system without any other microcontroller, however I've not had much experience with the AT Command set firmware.