Since I have several projects far away from my PC and also a laptop will not suffice, I wrote some software to debug anything with RS232 output over the air.

Essentially a Serial to Telnet Interface.

You'll need a NodeMCU/ESP8266. Might work with ESP32 (Not Tested).

Just connect your projects ...

Apparently the overall power consumption in 10Base T will increase (dramatically I might say):

From the datasheet of the LAN8720A chip:

Note 5-7 Current measurements do not include power applied to the magnetics or the optional external LEDs.
The Ethernet component current is typically 41mA in ...

That seems to explain it:

Note 5-7 Current measurements do not include power applied to the magnetics or the optional external LEDs.
The Ethernet component current is typically 41mA in 100BASE-TX mode and 100mA in 10BASE-T
mode, independent of the 2.5V or 3.3V supply rail of the transformer.

Not finding this earlier I opened a somewhat similar thread:
http://esp32.io/viewtopic.php?f=19&t=44097&sid=7a17091ebaecdcd74edd76570e429587

I managed to set LAN speed to 10M, but the strange thing is that the entire setup (WT32-eth01) draws 120mA with 80Mhz CPU and 100M LAN speed, but when I lower ...

UPDATE

I managed to set it to 10M. Done some research. The LAN8720A chip I have is a 'C' version and does not have the anomaly that versions A and B have. I did, however, also tried to set the registers directly.

Now the strange thing is that when i do NOT (re)set it to 10M the current consumption ...

Dear forum.

Got a WT32-eth01 board. I tried a few examples it works.

I do not need extreme speed, I do need less energy consumption. It now draws on average some 160mA

I read (part) of the datasheets. Lowering the CPU frequency should help and also lowering the LAN speed should help. In theory ...

Well you could use one GPIO port to do that, 2 resistors and a transistor

resistor 1 from GPIO port to base transistor, make it 1k Ohm
emitter to GND
Collector to 2nd resistor 100 Ohm, other end of resistor to the + of the charger.

Now when the current is too low, make GPIO port high ...

Dear forum

Till now I never worried too much about RAM size in my projects, but today I noticed this after compiling a rather large program:

. Variables and constants in RAM (global, static), used 48480 / 80192 bytes (60%)
║ SEGMENT BYTES DESCRIPTION
╠══ DATA 1724 initialized variables
╠══ RODATA ...

Just a suggestion out of the box: Does your piano (also) have the original DIN plug Midi input/output? The MIDI protocol is just simple RS232 at a baudrate of 31250. The basics are very simple, key(note) ON, key OFF and speed (as to determine how hard you hit the key). You could use the UART for ...

Thanks!