ESP8266 Wifi Shield spits out garbage data using example sketch.

Wireless & IoT Wifi
1

Hello,

I’m using the example sketch ESP8266_Shield_Demo from the ESP8266 AT Library. I have the shield set to software serial and I am using a SparkFun RedBoard - Programmed with Arduino. I have attached a picture of the serial monitor.

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I have the same problem with this sketch I created from the example code listed in the wifi shield hookup guide.

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Thank you,

Rose

2

Hi Rose,

That error looks like a baud rate mismatch. I’m curious if the ESP8266 on the WiFi Shield is running at a different baud than 9600 (default). From your post history it looks like you re-uploaded the AT Firmware so I would recommend connecting directly to the WiFi Shield with an FTDI (or whichever USB-to-Serial adapter you are using), opening a serial terminal and then manually set the UART configuration with the [AT Command Set. That command is outlined in section 3.2 of the linked guide and is command #7.

If you’re not sure how to do that or if setting that manually does not help the issue, let me know and we can troubleshoot further.](https://cdn.sparkfun.com/assets/learn_tutorials/4/0/3/4A-ESP8266__AT_Instruction_Set__EN_v0.30.pdf)

3

Hi Mark,

Using the arduino ide I was able to figure out that the esp8266 is running at baud rate 74880. I have attached a picture of the serial terminal.

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Thank you,

Rose

4

The exact contents of the serial monitor is:

Fatal exception (0): 
epc1=0x4024065c, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000000, depc=0x00000000
5

I think the problem has to do with flashing the firmware. Where is the correct AT firmware bin file located that I should flash?

6

The firmware will be in the [WiFi Shield Hardware GitHub Repository. You could also try setting the baud rate manually using the AT Command Set to try and get everything back to stock behavior. There are commands to reset to default UART configurations as well as a full factory reset function. I would probably re-try uploading the firmware linked above and if you’re still having problems, send the AT Command to first the default UART and if it still is misbehaving, sending the factory reset command may be necessary.

Let us know if you continue to have problems after this but hopefully, this will get your WiFi Shield back to sane values. If after all of that you’re still not able to reset it, we could probably have it sent back to SparkFun for repair/testing on our production hardware to get it back to the default state the shield ships with.](ESP8266_WiFi_Shield/Firmware at master · sparkfun/ESP8266_WiFi_Shield · GitHub)

7

Hi Mark, I have tried flashing both binary files from the Firmware/bin folder from the github repository. The “SparkFunWiFiShield-070715.irom0.text.bin” file just causes the esp8266 to print this:

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It is unresponsive to any AT commands.

I also tried flashing the file “SparkFunWiFiShield-070715.flash.bin” but that resulted in the esp8266 continuously printing the aforementioned :

Fatal exception (0): 
epc1=0x4024065c, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000000, depc=0x00000000

I used the nodemcu flashing tool listed on the hookup guide to flash the binary files.

Thank you,

Rose

8

Hi again Rose,

Sorry for the delay. I think at this point the shield is not going to work properly. Putting it on our testing hardware might recover it but that may be more trouble than it is worth. Assuming you purchased the WiFi Shield directly from SparkFun, please fill out the form on [this page and we will follow up with further instructions on that process.](Return Policy - SparkFun Electronics)