Wednesday 20 May 2015

Mini WiFi-Throwie with CR123A

Last night I finally found the time to fire up the soldering iron and try the CaptiveIntraweb with a CR123A cell.
As expected, this worked without any issues. From the data sheet, I expect a run time of approx. one day, although I haven't tried that yet.
Again the discharge rate of  around 70mA ist significantly higher than the 20mA mentioned in the data sheet. From this page it looks like the Panasonic cell is the best choice for high discharge currents.
A bit of tape (Kapton tape should be the ideal choice) to told it together and that's it.
Just don't forget to recover the throwie after the battery is drained and recycle it properly.

I will have the video on my Youtube Channel as soon as I have it ready.

Tuesday 5 May 2015

Flashing & running the ESP-201 module

Up to now I only had access to ESP-01 modules. The ESP-201 has a few extra pitfalls.
To flash the firmware, connect the following pins:

  • GND / VCC / RXD / TXD the usual way
  • CHIP_EN to 3.3V
  • GPIO00 to GND
  • GPIO02 to 3.3V
  • GPIO15 to GND

To run the newly flashed firmware:

  • GND / VCC / RXD / TXD the usual way
  • CHIP_EN to 3.3V
  • GPIO00 to 3.3V
  • GPIO02 to 3.3V
  • GPIO15 to GND
Apart from the CHIP_EN, the GPIOs might be left floating when they are marked 3.3V in the table above.
I haven't done anything fancy yet. Just flashed it with NodeMCU and tried a couple of my scripts. I can't wait to try stuff on the additional GPIOs.

I bought the module here.

Monday 4 May 2015

Schematic diagram for the CaptiveIntraweb Wifi-throwie

My CaptiveIntraweb has been featured on Hackaday and received a lot of attention lately.
Although it could hardly be any simpler, here is the schematic diagram for it:

Here are the components:

Here is the link to the original video:
And here the GitHub Repository: