Hello, I’m really new to this so I was wondering if anyone could help me out with this. So I recently got a Sparkfun ESP8266 and found out that I need a USB-to-Serial converter. My teacher gave my a µUSB-PA5-I he had lying around and told me to use this to program my Sparkfun ESP8266. However I don’t know which pins µUSB-PA5-I connect to which pins on the ESP8266. I was connecting them like so RX → RX1, TX → TX0, GND → GND, DTS ->, CTS - > NC, and 5v to VIN. If someone could help my figure out the correct connection pin layout that would be very helpful. Thank for taking the time to read this.
Hi KappaBerry,
That specific USB to Serial bridge may not work well with the ESP8266 Thing but there is another issue here that is probably causing the issue. When you are making the connections between the USB-PA5 and the Thing, you want to run RX->TX and TX->RX like the photo in [this section of our Hookup Guide kind of shows. To verify the connections, I would refer to the [Graphical Datasheet. Also, you’ll want to make sure you tie the DTR line together between the USB-PA5 and the Thing. The ESP8266 needs to be reset to enter bootloader and receive code.
The other potential issue is the logic level of the USB-PA5. You should be okay since it appears those serial lines operate at 0 and 3.3V but that might also be what is causing the issue. Finally, I would recommend powering the Thing via the micro USB connector while programming instead of Vin for more reliable uploads. If that does not work, I would recommend getting one of the recommended USB-to-Serial bridges we list in the Programming section of the Hookup Guide I linked above.
I hope this information helps you program your ESP8266 Thing. If you continue to have problems or have any other questions about the Thing, please reply to this thread and we would be happy to help as much as we can.](https://cdn.sparkfun.com/datasheets/Wireless/WiFi/ESP8266ThingV1.pdf)](https://learn.sparkfun.com/tutorials/esp8266-thing-hookup-guide/programming-the-thing)
Thank you for taking the time to reply Mark. I should probably mention that the serial converter is µUSB-PA5-II not the I, I don’t know if that changes things but I thought I should let you know . I’ll updated the title after this post. Anyways I got the serial converter to turn on and got the computer to read it as a open COM(COM9) however now when I try to program the ESP8266 I get this error message
warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_open failed
I’m sure this is a result of my wiring which I believe I messed up. Here is a circuit diagram of how I wired the serial
converter to the ESP8266. If you could please point out what I did wrong and what needs fixing that would be of much help. I’ll try and get the serial bridge you guys recommended if this one doesn’t work. Again thank you for taking the time to help me.
KappaBerry:
Thank you for taking the time to reply Mark. I should probably mention that the serial converter is µUSB-PA5-II not the I, I don’t know if that changes things but I thought I should let you know . I’ll updated the title after this post. Anyways I got the serial converter to turn on and got the computer to read it as a open COM(COM9) however now when I try to program the ESP8266 I get this error messagewarning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_open failed
I’m sure this is a result of my wiring which I believe I messed up. Here is a circuit diagram of how I wired the serial
Circuit.jpg
converter to the ESP8266. If you could please point out what I did wrong and what needs fixing that would be of much help. I’ll try and get the serial bridge you guys recommended if this one doesn’t work. Again thank you for taking the time to help me.
Hmm,
I think there are probably a couple of issues going on here. First, can you take a few photos of your actual circuit and attach them to your response? Especially any soldering you have done. The “espcomm_sync failed” error usually means there is a connection problem with the programmer so it may be related to your wiring or a physical connection issue.
Also, your wiring diagram does not look correct. You want to power the ESP8266 Thing via the micro USB connector on that board. Then, you really only need four connections:
RX → TX
TX → RX
GND → GND
DTR → DTR