ESP8266 Community Forum

There was a tiny package from China sitting in my mail box this afternoon. The package contained three ESP-12 modules and adapter boards (ordered from here).

First reaction upon removing an ESP-12 from the anti-static bag: "Hey! These are surface-mount. I guess I get to figure out how to solder surface-mount components a couple weeks ahead of schedule." My soldering irons may not be up to the task, but could one not reflow solder these in a toaster oven? I've got the solder paste and could experiment on some veroboard first. Sound crazy? I'm not sure if the header pins would survive the toaster oven treatment and may choose to solder them with a soldering iron instead.

Second reaction: "Hey! The adapter board doesn't break out the pins on one end of the ESP-12 module." A couple more GPIO pins won't make or break me, but it looks like hardware SPI is on those unconnected pins.

The quality of the ESP-12 boards looks better than the ESP-01 boards I received. At least, the stencilling is much more legible.

After experimenting with uncontrolled toaster oven reflow soldering and only getting a 50-50 success ratio, I decided to try hand soldering the ESP-12 modules to the breadboard adapter. Piece of cake.

Once I accepted that a breadboarded circuit is required to flash the ESP-8266, unlike the more plug-and-play Arduinos, I realized that there were all sorts of power options sitting around: A lab bench power supply made from a PC power supply, a bunch of AMS1117 modules, and some 120v AC to 3.3v DC adapter modules that arrived in the mail this week. Since I ultimately want to make a convenient perf-board programmer, I decided that the 3.3v DC adapter modules would probably be best. Dug up a dollar store plastic food container for a project box (got to protect myself from the AC), grabbed a salvaged PC power cord and went to work. Just plugged it in a few minutes ago. (Note to self: Add a switch on the AC power side.)

It's just power at the moment, but I can at least see the module is providing a wifi AP. So that's a success.

Next up: Serial communication.

Happened to be driving by our local recycling centre / dump and thought I'd have a peek in the electronics bin. Snagged a 12v and 9v AC-DC adapters. The 9v adapter seemed like a nice match for the MB102 breadboard power supply. Got home and got to work with a breadboard. I can now interface to it via serial on UART0 or UART1 (but only one at a time because I only have one USB extension cable at the moment).

Unfortunately, I am getting a "MEM CHECK FAIL!!!" message after booting the ESP-12. Frankly, I'm just happy that there is a message at all. And there are only a couple of bits to add before I can begin flashing the device. Hopefully a different image will fix that message. The message occurs on the two (of three) modules I've tried.

Rural wrote:Unfortunately, I am getting a "MEM CHECK FAIL!!!" message after booting the ESP-12.

I see that MEM CHECK FAIL message alot of the time... yet my uploaded program usually works... Maybe it means that the test itself is NFG...