I’m suspecting hardware issues with my ESP-01 WiFi board, how can I check this?

  • Is there a red light on the ESP-01?
  • Try disconnecting everything but 3.3V and GND.
  • If the ESP-01 works with just +3.3V and GND (Pins 1 & 8), connect  (TX pin 2), and test again, then RX (pin 7), then GPIO2 (pin 3).
  • If the blue LED is lit, but it is faint or it seems to flicker on and off when you touch the wires, contact us for a replacement board.

Trying to upload a sketch over WiFi, gives me the following error: “avrdude: stk500_recv(): programmer is not responding Avrdude: stk500_getsync() attempt x of y: nt in sync: resp=0x00”

The errors you are getting when the upload failed typically occur when the IDE can’t connect to the ESP-01. Some of the reasons this may happen are:

  • ESP-01 is not powered on.
  • ESP-01 is not connected to WiFi (wrong SSID/password, too far away from router) – Invalid SSL certificate or incorrectly installed Certificate Authority.
  • Failure of the DNS system to map the hostname to an IP address.
  • Connection is already in use (i.e. the DriverStation is connected to the ESP-01).

It seems I’m still having connection issues. Possibly related to the CA Certificate?

The following list might solve the Certificate issues:

  • Make sure the Root Certificate is installed properly! Follow the steps outlined on our resources webpage.
  • If your ESP-01 is connected to your local WiFi, it should automatically acquire a proper SSL certificate. Another alternative is to find the IP address of the ESP-01 on your network and use the IP address instead of the hostname.
  • To tell if the CA is properly installed , browse to https://yourelegoo.local/ If you don’t get a security warning, the CA is properly installed. Otherwise try to re-install the certificate.

I can access the ESP-01 WiFi board at it’s own local IP address, but I’m having issues connecting to it over my local WiFi (http[s]://yourelegoo.local and/or local WiFi IP address.

This can be caused due to several reasons.

Any connection issues related to the http[s]://yourelegoo.local is usually caused by mDNS (MultiCast DNS) not working properly on your local WiFi router or due to a local firewall. Here are some pointers you might want to consider:

  • Local WiFi network needs to be set to public (not private).
  • For Windows OS, try going in to “Firewall & network protection” -> Advanced settings -> inbound rules and make sure all 3 mDNS entries are enabled, likewise for outbound rules.
  • For Windows OS, Check this registry key: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\EnableMulticast.
  • Turn off all external firewalls, such as AVG (you may want to re-enable your firewall when not using the Elegoo car for safety).
  • For Windows OS, uninstall Apple Bonjour Service.
  • Removing IPv6 from the wireless network adapter if your router is set up with only IPv4.
  • Turn DNS Filtering off on your router for the Elegoo IP.
  • The main reason why the “programmer not responding” happens is that the socket can’t be opened (another program is connected to the ESP-01 or mDNS name lookup failure are the top reasons).

What firmware should I be running? Where can I tell what firmware I have and how can I enforce an update if there is an issue?

The current firmware version is 0.9.9 (latest version can be found on the website).
You can check the firmware version on your ESP-01 on the admin webpage found at https://tcp2elegoo.local/ (kit default) https://yourelegoo.local/ (yourelegoo is the name you gave your ESP-01, if you changed it) or https://ip-address/ (given by your router, e.g.

You can update the firmware directly from the admin webpage or if required download the latest version at https://elegoo.wwfirst.ca/esp-01/Tcp2Serial-loader.bin. Browse to your Elegoo ESP-01 at https://yourelegoo/update to update the firmware with the downloaded Tcp2Serial-loader.bin file.