ESP8266 Community Forum

After successfully prototyping some stuff on NodeMCU devkits, I'm ready to produce something a bit more "final".

I picked the ESP-07 because of the possibility of the external antenna, even though it means more work (soldering to a breakout board, etc.) I am lazy and would have preferred a WeMos style, ready-to-go chip, with built-in USB, but didn't want to lose the antenna*.

Anyway, I got the chips and the breakout boards, and even managed to solder them without incident (my first ever SMD soldering ) using paste but with an iron, as I don't have a hot-air gun. No problem, all fine, and I flashed the the chips with the "cloud build" I wanted without incident.

Now what I want to know is:

1) The ESP-07 has two antennae, the on-board ceramic one and the receptacle for the external one. Are these two DESIGNED to work together?
In other words, will it work better with the external antenna if I remove the ceramic, or will it make no difference? Perhaps it might even be detrimental to the chip, especially if at some stage it finds itself working with no antenna at all (by mistake).
My knowledge of such RF technicalities in next to zero, hope someone can pitch in here.

2) The breakout board I used (pretty standard from the various auction sites) has a solder pad on the back for a 5V to 3.3V converter/regulator. There is also a short-circuit (0 ohm res) on the board. If this is not removed, the 3.3V chip pin goes directly to the VCC breakout pin. If that happens to be 5V there may well be a problem. If it's removed the 3.3v passes through the converter first. This is what I'd like to do, as the rest of the project is working at 5V, and it will save me from having an external converter (as I do at the moment). So I ordered a few AMS1117s, since that is what I've seen being used everywhere else.

However, when I checked I found that not only are these chips WAY too wide for the pad (about double) they also have the wrong pin-outs. The pads on the breakout board are: left-GND; center-5V; right 3.3V -- whereas the 1117s are left-GND; center 3.3V; right 5V.

Does anyone know if there is another regulator that will fit on this pad, or is this just an example of the bad design that occasionally finds its way into cheap products from the Orient? Any suggestions appreciated. I mean, no big deal to have the regulator external but if there is a better, on-board solution so much the better (Basically a regulator with the right pin-out),

Many thanks!

Below is a pic of the reverse of the breakout board. I'm not even sure it's the right scale, but seems reasonably similar to mine:




* PS. I just saw that there is a WeMos board available with an external antenna, the so-called "Pro", but it costs more than double the price of an ESP-07 and has no RF screening. It does claim to have 16M flash though, which is cool but not something I need.

1) The ESP-07 has two antennae, the on-board ceramic one and the receptacle for the external one. Are these two DESIGNED to work together? In other words, will it work better with the external antenna if I remove the ceramic, or will it make no difference?"

I found the ESP07 works properly if you just plug an antenna into the connector. I've never tried to disconnect the ceramic antenna.

However, when I checked I found that not only are these chips WAY too wide for the pad (about double) they also have the wrong pin-outs.

The regulator may be an HT7333, it is commonly used on breakout boards. The pinout doesn't seem right but the width is about half that of an LD7111.

daniel_ezsbc wrote:The regulator may be an HT7333, it is commonly used on breakout boards. The pinout doesn't seem right but the width is about half that of an LD7111.

Thanks Daniel pal!
I'm sure that's the right one, I checked the datasheet for pin outs and they are in the right order too, I've ordered some already, should have them in a couple of days. I'll let you know if it wasn't the right one! LOL

1) The ESP-07 has two antenna, the on-board ceramic one and the receptacle for the external one. Are these two DESIGNED to work together?

They are not designed to work together. Just because it works does not mean it is working properly. I have a ESP-07S and I can use it without an antenna. (it does not include the antenna like the ESP-07) It works. But of course it has less signal for transmit and receive.

If you are using the external antenna with the ESP-07 then you should remove the shorting resistor that brings the connection to the on board antenna.

Does anyone know if there is another regulator that will fit on this pad, or is this just an example of the bad design that occasionally finds its way into cheap products from the Orient?

It is a horrible design. A waste of effort. I use some but have since designed my own. I did use a larger regulator on the bottom of the crappy China breakout board. I soldered two of the pins to the pads and used a short piece of solid wire to make the third connection. I also added additional parts to the board to make it more usable.



The following picture is something someone else had done.