[En-Nut-Discussion] Power Consumption - TCP/IP

[Harald Kipp]

Interesting project and ...


>the amount of power consumed by one instruction. Any suggestions on
>how I can get the number of instruction executed....


... interesting question. May be Philipp Blum's os/tracer.c
can help to give a rough estimate.


>Else the other approach that we have thought is by trying to connect a
>battery and see for how long it can run....

On 100 MBit Ethernet, the Ethernet Controller is for sure
the main energy spender.

Btw. the origin Ethernut design is not very well suited for
battery supplies:

1. The rectifier bridge costs 1.4 Volts. This can be
reduced by replacing it with a single Schottky Barrier
Diode, or, for the adventurers, use no diodes at all.

2. The linear regs consume a lot of power. The LM1086
requires a Vf of 1.2 Volts. There are regs with 0.7 Vf
(if I remember correctly). But there is still the 5V->3.3V
regulator. Better use an ATmega128L and run the whole
board @ 3.3V, 3.6864 MHz. Nut/OS works quite well on
such a slow system...however, in your case, TinySec might
be a problem.

Harald