Miss At Supercon: ESP32 Mesh Network Demo

In the pre-Superconference badge hacking call to action, wireless badge communication was raised as a specific challenge laid out for attendees to tackle. One particularly ambitious effort was to build a mesh network for wireless communication using ESP32 modules mounted to the badge expansion header. The ESP32 mounting system is straightforward, it was the software that would prove to be tricky.

At the end of the weekend, Morgan and Ben got the network up and running with just over an hour to spare. They started recruiting people to join their IRC-style chat network for the final demo, and I signed up. In the test session I was able to see messages sent over the network, and send a few myself. But when it came time for the actual demo on stage, my badge was unable to connect! Fortunately they had enough other participants so my participation was not critical, but I was sad to have missed out. After the presentation (and winning a prize) the team told everyone on the network we could keep the ESP32 as a token of thanks.

After the conference I examined my ESP32 mount and found a few cracked solder joints. It looks like I had accidentally smashed my ESP32 module sometime between the test session and the presentation. Looking on the Hackaday.io project page, I found the simple schematic and tested connections using my multimeter. Several connections were indeed severed between the badge header and the mounting circuit board. I tried the easy thing first by reheating all the solder to see if they could bridge the gaps. This helped, but two lines remain faulty and were patched with wires.

After this patch, I tested with [mle_makes] ESP32-equipped badge and we could not communicate, indicating further problems with my ESP32. The next step is to desolder it from the board to see if I could use the ESP32 as a standalone module. Once the module was removed from the carrier board, I saw a problem: three of the pads had separated from the module, one of them being the EN(able) pin critical to a healthy ESP32. The other two damaged pads (IO34 and IO35) I hope I could live without.

Is this the end of the road for my gifted ESP32? I thought it was, but [mle_makes] disagrees. The next experiment is to try soldering to the trace leading to EN pad, or the via further inboard. This will be a significant challenge – that via is smaller than the tip of my soldering iron! 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s