ESP8266 Community Forum

Based on several posts I decided to design another board. I still plan on releasing the Solar Powered board but this one is slightly different. It is designed to run off of 2 AA batteries and fully deplete them. In theory this circuit can work off of 1 AA/AAA battery but the supported current is reduced and may not work under all circumstances (although most should still work).

The circuit also has a separate chip that is a timer that can be configured to power the ESP module at different intervals. This is useful for those code challenged people who just want something to happen every 1 minute or 10 minutes or 1 hour. Adding this chip allows the system to run at nA levels when you aren't doing anything.

The board accepts either the ESP-01 module on a header or soldering down one of the ESP-07 or ESP-12 modules. Reverse voltage protection is in place as well as jumper to bypass the timer, apply external power rather than a battery, or remove power to the ESP modules.

Of course there are also headers to the serial connection, a breakout header (with power and ground) for GPIO pins, and a reset button.

Her's a picture of the design which is just slightly larger than a 2 AA battery holder (2.5" x 1.3" / 6.3cm x 3.3cm).

Comments and suggestions are greatly appreciated!!

George

That looks great! Will you give us the schematics?

I would perhaps add some holes to be able to mount it somewhere.
Also what are the green parts beside the headers and the white "sticks" on the right side?
For the external connection, do you have some protection against more than 3.3v or a voltage converter?

Yes, I'll be providing everything just like the Solar Powered board but I want to review this a little more before releasing.

I thought about the mounting. What could be done is to use the battery holder holes but with longer screws. Since I was trying to keep this as small as possible the only place for the GPIO header was between the 2 battery holder holes. I was trying different attachment methods to see if there was enough clearance. The bright green color is applied to parts that have clearance issues. I think if the through hole header was trimmed just a little bit everything would just fit, it would be very tight but there would be enough room to either use a nut or a standoff. There is plenty of clearance around the actual hole (0.130"/3.3mm) so a long screw would fit without any issues.

I would like to enlarge the board so it is larger than the battery holder so you could have other mounting holes but I wasn't sure what everyone's preference would be. This is a 2 layer board so that will help to keep the cost down for everyone.

The "sticks" on the right are actually the battery holder posts, they get trimmed after assembly.

Yes, there is a 5V TVS Diode across the terminal block inputs

GeorgeIoak wrote:Based on several posts I decided to design another board. I still plan on releasing the Solar Powered board but this one is slightly different. It is designed to run off of 2 AA batteries and fully deplete them. In theory this circuit can work off of 1 AA/AAA battery but the supported current is reduced and may not work under all circumstances (although most should still work).

The circuit also has a separate chip that is a timer that can be configured to power the ESP module at different intervals. This is useful for those code challenged people who just want something to happen every 1 minute or 10 minutes or 1 hour. Adding this chip allows the system to run at nA levels when you aren't doing anything.

The board accepts either the ESP-01 module on a header or soldering down one of the ESP-07 or ESP-12 modules. Reverse voltage protection is in place as well as jumper to bypass the timer, apply external power rather than a battery, or remove power to the ESP modules.

Of course there are also headers to the serial connection, a breakout header (with power and ground) for GPIO pins, and a reset button.

Her's a picture of the design which is just slightly larger than a 2 AA battery holder (2.5" x 1.3" / 6.3cm x 3.3cm).

Comments and suggestions are greatly appreciated!!

George

Hi George,

Do you perhaps have the schematics available? Are these and the 3D model done in KiCAD?

Thanks
Johan