An Arduino based Power Meter

Well,

I've been fiddling some more since the Linear we built a little while ago here.

Some musings below on power meters, directional couplers and measuing RF power:

I hope you are all keeping safe - its very scary out there.

TFTs and Blue Pills - Are you sure?

Well,

I've been using the STM32 processor (STM32F103 for those playing along at home) based "Blue Pill" board. This board is compatible with the Arduino IDE and I have been using it with the ILI9341 super duper TFT display module.

This is the board in question:

The STM32 board support can be added easily to the Arduino IDE, just add this line:

https://github.com/stm32duino/BoardManagerFiles/raw/master/STM32/package_stm_index.json

to the preferences screen:

Once you have done that you can then install the STM32 cores from the board manager:

I wrote some very simple code to generate Pi using floating point maths:

Set to calculate 100,000 itterations, the good old Arduino Nano ran this code in 29.60099983215332031250 seconds. This Blue Pill board runs the same calculation in 3.07200002670288085937 seconds. Cooking!

Here' how I have wired the test up for the TFT:

I have used the library called "TFT_eSPI" which is here. In the more modern Arduino IDE you just search for it and install from the library manager.

Once you have done that you need to make a couple of edits to the "User_Setup" file which you can find in the libray directory.

Here's mod 1:

and this is mod 2 - please use pins of your choice here:

Once you have done that all should be well!

Please note that this library and config only works with the Arduino STM32 cores and the HID bootloader.....