Many thanks to readers in here for the comments – I can’t believe how keen people are to help. Ok, so you may recall that some time ago I bought an ESP-201 board and the baseboard to with it – the whole lot was about a tenner on Ebay, a marvellous opportunity to play with the ESP8266 while accessing all the pins AND on a 0.1” pin centre basis – easy for prototyping.
Well, it didn’t work out that way, the whole package came with zero documentation and frankly the sensitivity of the aerial was ATTROCIOUS or so it seemed. I’ve had feedback from a couple of you and so this morning I decided to go take a look with my new microscope (another Ebay special).
So what did I find? Well, sure enough – look at the board on the right – the centre part is the little ESP201 board itself. See the aerial – see the little link on the right? See the or SMT resistor to the left of it? Does that look like there’s a track going from the chip to the aerial?
No, you’re right – it DOESN’T – the damned thing is connected to the external aerial!!!
Just to exaggerate the point here’s another photo in which (click to zoom the image) you can clearly see that the 0r resistor is designed to offer a choice, horizontally it connects to the internal aerial, vertically (default) it connects to the external aerial – why on EARTH would anyone do that?
I’d given up on this board on the basis (again in the absence of any documentation) that it was just a really bad design. Wouldn’t a link have worked??
I don’t know how many of you have tackled surface mount but let me tell you – if your hands shake – forget it. If they don’t, you need a nice set of tweezers with a 45 degree end on them. If you apply the iron to one side, the chances are both sides of the 0r resistor soldering will melt and you can lift the part off cleanly, Ensure your iron is hot – and as clean as possible.
Anyway, thanks to a nice set of snips and a fine soldering iron… a few moments later… I FREELY admit, moving that resistor was neither the finest hour for me or my cheap Chinese tweezers and as I didn’t have any isopropyl handy it’s a little messy – but ultimately it’s a 2 minute job to change the link over. Actually a blob of solder would have done because a 0r resistor is pretty much just a wire.
Did it make any difference? No – not at all – the unit after blowing the chip powered up and would not connect to the router. With some repositioning, it would – which clearly indicates a sensitivity issue.
Frustrated with that I took my sparkly new ESP-7-8-12 baseboard (which has 2 resistors and nothing else, soldered on an ESP-12, wired it (0.1” centres) to my ESP-01 adaptor (the board shown on the left already has a pull-up for CH_PD and a pull-down for GPIO15), blew the chip, turned it on – no problem at all.
I’m beginning to think that life is too short to spend much more time on those EP201 board especially considering the cost of the ESP12s, the fact that they are shielded and that adaptors are so cheap… Next stop – making sense of the A/D so I can use it as a battery voltage indicator.