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newRPL: [UPDATED April 27-2017] Firmware for testing available for download
04-12-2016, 02:41 AM
Post: #253
RE: newRPL: [UPDATED Mar-09-16] Firmware for testing available for download
(04-11-2016 07:36 PM)Nigel (UK) Wrote:  Since flashing my HP-49g+ with newRPL on more than one occasion the machine wouldn't switch on because the batteries were flat. I have blamed myself for leaving it turned on as after all there is no auto-power-off yet.

This evening I decided to measure the current drawn by the calculator. I put two strips of copper separated by an insulator in series with the final positive battery terminal and connected the strips to a meter set to its 200mA range. The calculator switched on when the circuit was complete; the current drawn was 80mA. Switching it off via the keyboard, the current dropped to 10mA. Switching on again, this time via the keyboard, the current drawn was about 40mA. The current drawn when switched off was still about 10mA.

These "off" currents seem far too high (and the "on" currents as well, although I'm less certain about those). Can anyone else confirm them? In particular, does the HP-50g when flashed with newRPL suffer from the same problem?

Nigel (UK)

(In case you are wondering - I definitely mean mA, not microamps!)

If the IO pins are not properly setup there can be currents when off, and that's something I need to investigate and correct. I didn't notice any problems on my 50g, batteries last quite long now that I have enabled auto-power off I'd say about the same as my other 50g with stock firmware.
10 mA is a lot of current, there might be something setup incorrectly, I just need to figure out what it is.
There's virtually no difference in hardware between a 50g and 49g+, except for an extra battery and the circuitry to power the calculator from the USB port. That's where I should start looking.
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RE: newRPL: [UPDATED Mar-09-16] Firmware for testing available for download - Claudio L. - 04-12-2016 02:41 AM

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