Is the 12C SDK still available?

[matthiaspaul]

(11-22-2015 05:47 PM)rprosperi Wrote:  1. If the case (and presumably the 6-pin connector) are the same, is there any danger of harming the new units if I use the older (serial) cable? Or I suppose the opposite as well (though less likely with lower voltages?)

(11-22-2015 06:31 AM)Katie Wasserman Wrote:  

Code:


||
||   1    2    3    ||
||   4    5    6    ||
||

1 - reset button (connect to ground)
2 - ground
3 - erase button (connect to pin 4)
4 - erase button (connect to pin 3)
5 - USB green wire (data -)
6 - USB white wire (data +)

Assuming that this is meant to be the view onto the calculator and applying the standard pin naming scheme for dual-row pin headers suitable for flex-cables, the pin numbering would change as follows:

View onto 2x3 pin header on connector:

Code:


||  ||          ||
||   1    3    5   ||
||   2    4    6   ||
||

View onto 2x3 pad array on calculator:

Code:


||
||   2    4    6   ||
||   1    3    5   ||
||  ||          ||

Pinout of 2x3 flash connector on AT91SAM7L128 based calculators like
HP-12C (F2230A, 2008-2015) aka "HP-12C+", HP 12c 30th Anniversary Edition (NW258AA, 2011), HP 15c Limited Edition (NW250AA, 2011) aka "HP-15C+", HP 10bII+ (NW239AA, 2011-2015), HP 20b (F2219A, 2008-2012), HP 30b (NW238AA, 2010-2014):

1 VBAT (connect to pin 6 to erase)
2 NRST (connect to pin 4 to reset)
3 TXOUT (direction as per calculator view)
4 GND
5 RXIN (direction as per calculator view)
6 ERASE (connect to pin 1 to erase)

Pinout of 2x3 flash connector on SAM4LC2CA based HP-12C (2015+) and HP 10bII+ (2015+):

1 ERASE1 (connect to pin 6 to erase)
2 NRST (connect to pin 4 to reset)
3 USBD- (bidirectional)
4 GND
5 USBD+ (bidirectional)
6 ERASE6 (connect to pin 1 to erase)

So, the pinouts of the two connectors are for the most part compatible:

USB data lines have much lower operational voltages, but per the USB specification the circuitry must be able to withstand ca. 3.3V on them, so there isn't any risk of damage when using the old serial programming cable on the new USB calculator model - it just won't work. Well, in theory (depending on the boot loader code), it would be even possible to support both, USB and serial I/O over these pins.

For the serial pinout there was a risk to permanently damage the calculator when not powering the calculator externally (through VBAT) without batteries, but through older batteries inserted. This risk does not exist for the USB pinout any more, as USB data lines aren't strong enough to reverse power the calculator through the clamping diodes.

The arrangement of the ERASE1 and ERASE6 pins certainly warrants some more investigation. It's possible that one of them is actually VBUS (or a 3.3V-compatible derivation of it).

Greetings,

Matthias