You can use the Arduino Uno as a USB to TTL connector allowing you to communicate with the ESP8266. BE ADVISED that the ESP8266 is rated at 3.3V and the UNO RX and TX pins are rated as 5V but i've had no issues so far.
Breadboard may be required to connect both VCC and CG_PD to 3.3V pin
I loaded the BareMinimum sketch, so that no previous sketch causes issues.
Once Connected open the Serial Monitor and set "Both NL & CR" and Baud to 9600.
Send "AT" to test. If nothing comes up try different baud rates such as 115200 or 57600 and retest.
If you get "OK" reply then all is working.
I've got it working using the Uno as described above.
The 8266 receives the commands sent through the Serial Monitor and also responds in the same way.
I also have a simple server working, although not yet working perfectly.
Thank you! Indeed, I've got it working by wiring TX -- TX and RX -- RX. However, I used an external power supply rather than Adruino's VCC. I've already heard that ESP8266 needs quite a bit more power.
hi, my esp suddenly started to reset and reset and reset!!! i don't know what to do!!! can you help me with that? I was using it normally until last friday then today I turn my project on and the esp is stuck in this loop! =/ btw I don't have a ftdi to update the firmware...
Thanks
I have been testing this module for a week now and still having some problems.
When I run the AT+CWLAP to check the WIFI networks around me I usually get "garbage response".
Maybe my module is not correct, but it seems very unstable.
How are you powering the 8266 module? The datasheet states the unit uses at a minimum of 135ma (max is 215ma) to transmit. If you are using the 3.3v pin on the Arduino to power it, that won't be enough. It is rated at 50ma max.
edit: It uses 60ma to receive. That is more than the Arduino can supply.
Hi i would like to ask something regarding the wiring for ESP8266
What about the TX and RX lines from arduino that they got 4,5Volts . what will happen if i directly connect them to tx and rx pins of esp8266. would be damaged? do i have to make a logic voltage down circuit with some resistors to get the rx and tx voltage of arduino to safe 3.3v?
Do you need to modify the Arduino beyond what is described above in order to enable the serial passthrough? I thought you needed to bypass the chip by shorting Reset to GND, like here.
I'm encouraged people are getting the device to work with straight connections to the 5V RX/TX lines. Do you not need a resistor between CH_PD and 3.3V?
I got mine last night, set it up with a voltage divider like this, but serial AT returns nothing on any baud rate.
My ESP8266 is booting (blue led, then constant red) and can be seen as an open hotspot, so it's hopefully getting enough power. But the lack of AT response is frustrating! I'm thinking to simplify the wiring per the instructions here in case the fault is mine. Also worried about pin damage, they were a little crushed.
Not my first experience with Arduino but first time on the forum. Hello
Bypass the MCU with a jumper RST-GND. You can remove MCU entirely if desired, not sure why you'd prefer that.
Forget the voltage divider. Just more stuff for me to mess up! The TX/RX pins are 5V tolerant. The rated voltage is 3.6, but it'll go beyond 5V before a protection switch kicks in. Obviously you do this at your own risk.
Use the Arduino 3.3V rail for power. An external source wasn't necessary, for me. But external power would have been my next step for sure.
Connect TX-TX and RX-RX. Why? I don't know. But it works. After I did this, I started getting something back, even if garbage, without the correct serial baud settings.
Use 9600 baud, with NL+CR selected. Given the wide variation reported, this won't be the case for everyone.
Basically a lot of that is not "recommended" but I've seen more than one person say that's what worked for them, and it worked for me too!
I used the arduino as FTDI with the 'bare minimum' sketch.
RX => UTXD and RX=> URXD ESP, shared the GND cable and used an external power adapter with regulator on 3.3V.
Worked out of the box on a macbook, not on a windows pc, to be continued.
fujisawa:
OK, wanted to report back on what worked!
Bypass the MCU with a jumper RST-GND. You can remove MCU entirely if desired, not sure why you'd prefer that.
Forget the voltage divider. Just more stuff for me to mess up! The TX/RX pins are 5V tolerant. The rated voltage is 3.6, but it'll go beyond 5V before a protection switch kicks in. Obviously you do this at your own risk.
Use the Arduino 3.3V rail for power. An external source wasn't necessary, for me. But external power would have been my next step for sure.
Connect TX-TX and RX-RX. Why? I don't know. But it works. After I did this, I started getting something back, even if garbage, without the correct serial baud settings.
Use 9600 baud, with NL+CR selected. Given the wide variation reported, this won't be the case for everyone.
Basically a lot of that is not "recommended" but I've seen more than one person say that's what worked for them, and it worked for me too!
fujisawa:
3) Use the Arduino 3.3V rail for power. An external source wasn't necessary, for me. But external power would have been my next step for sure.
4) Connect TX-TX and RX-RX. Why? I don't know. But it works. After I did this, I started getting something back, even if garbage, without the correct serial baud settings.
Output of Arduino 3.3 V is rated only 50 mA max... so be careful to use that pin with ESP because when connecting to wifi it can require up to 230 mA ! Better is to connect a series of 2 diodes from 5V pin and add also a Capacitor, min. 470 uF, from the end of diodes to GND. At capacitor pins You will then have about 3,3 V usable for ESP...
the reason of this TX/RX reverse is that without Atmel328 (to where the TX RX pins on the board are reffered) You will connect to the other Atmel32U16 TX RX pins... where these pins are obviously inverted
I first connected a ESP8266 with my Arduino Nano yesterday. I first tried with the direct power from the 3.3v rai in the arduino. No luck, the serial port went nuts, probably cause I was forcing the FT232 chip (the one that actually provides the 3.3v) too much.
Went ahead and used 2 diodes in series. Got connection right away. Im using the hardware serial for the debug/programming, and SoftwareSerial for ESP8266 connection, at 115.200bps. I manage to connect to my Wifi and open a socket.
BUT, the response messages from the ESP are sometimes garbled up...not always, just some chars. It just messes up one or two letter out of each response
What could it be? Lack of capacitor after diodes?
Unrealiable SoftwareSerial as some people say?
I added a capacitor in the 3.3 rail (my own rail created with 2 diodes in series). I still get wrong characters in the Rx from the ESP, check this real output:
ERROS
AT+ CIPSTATUS
