newRPL: [UPDATED April 27-2017] Firmware for testing available for download

[Claudio L.]

(04-12-2016 01:24 PM)Francois Lanciault Wrote:  Here is what I get on a HP-50G with Newrpl hooked to a 6 volts regulated power supply

Calculator ON : 42.3 milliAmps
Calculator OFF: 21.7 microAmps (2000 times less than ON state)

Same values with or without the SD card installed

François

(04-13-2016 11:59 AM)Nigel (UK) Wrote:  One further piece of information: I've re-flashed my HP-49g+ with the HP ROM 2.15. Current when turned on is 12 mA (with big pulses when keys are pressed); current when turned off is 18 microamps.

Edit: to be clear, I didn't notice the current pulses when pressing keys with the newRPL firmware installed. The current was high all the time.

Nigel (UK)

Some notes:
a) The calculator running at 12 MHz (stock ROM idling) consumes 12 mA. This is consistent with some old measurements posted in this forum.
b) The calculator 'spikes' when pressing a key because the stock rom changes the clock to 75 MHz and then back to 12 MHz.
c) newRPL uses 6MHz clock when idling, so current should be around 12 mA or lower, if it's 42 mA something isn't right, something must be mis-configured.
d) Why some calculators would not drain current and some others will is a mystery to me. Perhaps some hidden hardware revision that happened over the years. The configurations of pins are identical on power-up, and are not retained when power is lost, so all calcs should be good or all bad, unless something is different in the hardware.

I'll see if I can investigate more this weekend.