Does anyone have 15C LE dissection pics? - Printable Version +- HP Forums (https://archived.hpcalc.org/museumforum) +-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html) +--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html) +--- Thread: Does anyone have 15C LE dissection pics? (/thread-196943.html) |
Does anyone have 15C LE dissection pics? - Hugh Evans - 09-20-2011 I'm curious if anyone has done this yet. HP seems to have taken a liking to screws over heat stakes in recent years. If that is indeed the case with the 15C LE, I will take a stab at improving a couple of minor issues involving the keys. The first step will be that of taking the wiggle out of f and g. Then I will move on to filling them, probably with some polyurethane reactive hot melt to minimize downtime.
Re: Does anyone have 15C LE dissection pics? - Lincoln R. - 09-20-2011 I've opened the back of one. It's heat-staked, there's foam tape behind the LCD to keep it from bouncing around in the case, and the Atmel CPU is in an LQFP package instead of being a raw die underneath epoxy like my 12C+ is. I have a picture but the quality's not that great, I'll see if I can clean it up a bit.
Re: Does anyone have 15C LE dissection pics? - Katie Wasserman - 09-20-2011 It's the same as the 12C+. I've posted these pictures before:
Re: Does anyone have 15C LE dissection pics? - Eric Smith - 09-21-2011 Nice pictures of the 12C, but if Lincoln R. is correct, the 15C LE does NOT look the same. That seems rather surprising since there isn't any need for the hardware to differ.. I haven't opened mine, though, so I can't confirm.
Re: Does anyone have 15C LE dissection pics? - Tim Wessman - 09-21-2011 I believe the 15c uses a packaged IC. That is the only difference IIRC.
TW Edited: 21 Sept 2011, 1:28 a.m.
Re: Does anyone have 15C LE dissection pics? - Thomas Radtke - 09-21-2011 Does the AE 12C have bad keys, too?
Re: Does anyone have 15C LE dissection pics? - Katie Wasserman - 09-21-2011 Indeed, the PCB on the 15C LE doesn't have the potted chip on board, it's got the real packaged Atmel chip in all it's glory showing. If I'm reading this correctly the date code on this chip is from September 2009, ancient! Why the switch away from the potted chip on board? Is this the same in the 12C 30th AE and newer 12C+ calculators too?
Edited: 21 Sept 2011, 3:34 a.m.
Re: Does anyone have 15C LE dissection pics? - Thomas Chrapkiewicz - 09-21-2011 Katie: Nice work! This is indeed good news in enabling any potential hardware modifications or studies.
TomC
Re: Does anyone have 15C LE dissection pics? - Masaki Adachi - 09-21-2011 Are there instructions to open up the 12C+/15C LE posted somewhere? Edited: 21 Sept 2011, 12:02 p.m.
Re: Does anyone have 15C LE dissection pics? - Katie Wasserman - 09-21-2011 There are 6 screws to remove, one under each foot and two inside the battery compartment (one of these is smaller than the other 5). Once you do this it prys apart quite easily.
Re: Does anyone have 15C LE dissection pics? - Thomas Chrapkiewicz - 09-21-2011 The only mechanical constraints appear to be along the top and bottom edges of the case. ALSO BE CAREFUL: Try to have the calc face down as you pry it apart as there are three springs in plastic collars in the keyboard half of the calc which can fall out. (These are used to electrically connect the keyboard to the metal plate on the battery compartment half of the calc - for ESD protection.)
TomC
Re: Does anyone have 15C LE dissection pics? - Kerem Kapkin (Silicon Valley, CA) - 09-21-2011 Spec details on Atmel AT91SAM7L128 A member of the Atmel SAM7L series of microcontrollers based on the 32-bit ARM7TDMI processor. It operates at a maximum speed of 36MHz and features 128KB of flash and 6KB of SRAM. The peripheral set includes a 40-segment LCD controller, two USARTs, UART, SPI, TWI (I2C), three 16-bit timers, RTC and four 10-bit ADC. The SAM7L128 operates in single-supply mode down to 1.8V and consumes 0.5mA/MHz typical in active mode when executing code out of its flash memory, and a mere 100nA in power-down mode. The SAM7L128 is supplied in a 128-pin LQFP and 144-pin LFBGA packages.
It is the SAME Chip on HP20b Calculator:
Another good article about the 15c and ATMEL Processor
Edited: 21 Sept 2011, 1:26 p.m.
Re: Does anyone have 15C LE dissection pics? - hpnut - 09-21-2011 Katie,
is that lipstick on the Atmel chip? LOL!
Re: Does anyone have 15C LE dissection pics? - Katie Wasserman - 09-21-2011 Yes, but not mine. Probably whoever did the assembly in China was kissing it goodbye. If it were an HP-16C+, that might be another story.
Re: Does anyone have 15C LE dissection pics? - DaveJ - 09-21-2011 I haven't checked, but if there is a bigger memory chip in the same package, it could be replaced fairly easily.
Dave.
Re: Does anyone have 15C LE dissection pics? - Katie Wasserman - 09-22-2011
Quote:
There isn't one with a larger non-volatile RAM at least last time I checked.
Re: Does anyone have 15C LE dissection pics? - Kerem Kapkin (Silicon Valley, CA) - 09-22-2011 I remember seeing an AT91SAM7L256, I think that is double the memory. I will confirm and check on the packaging.
Re: Does anyone have 15C LE dissection pics? - Katie Wasserman - 09-22-2011 There's a AT91SAM7S256 with lots of RAM, but without the LCD driver and requires higher voltage and more power.
Re: Does anyone have 15C LE dissection pics? - Paul Dale - 09-22-2011 Flash isn't the big problem. RAM is. The 34S could use more RAM. Lots more. I know how to squeeze more into flash. It will require recoding many of the mathematics routines but it is possible.
Re: Does anyone have 15C LE dissection pics? - Katie Wasserman - 09-22-2011 There are a few spare i/o pins that are made available on the 20b and 30b PCBs. Have you experimented with adding a small serial non-volatile RAM chip? Such RAM wouldn't be in the calculator's memory space but you could write routines to page it in as needed or it might be fast enough to use for all memory access.
Re: Does anyone have 15C LE dissection pics? - uhmgawa - 09-22-2011 Quote: Very nice indeed.
Quote:
The change to (and developemnt cost of) a new board layout with
Frankly I'm still not sure how a bare sam7l die ended up in the Re: Does anyone have 15C LE dissection pics? - Eric Smith - 09-22-2011 Cost. In the quantities that HP makes the 12C, they are able to buy the bare die, attach and bond it, and encapsulate it, for less than what it costs to buy the packaged part.
The reason Atmel doesn't "openly sell" the part in bare die form is that they don't want to sell it that way to anyone that isn't buying a large volume and prepared to deal with the complexity of chip-on-board assembly. If you design a high-volume product, you can negotiate a bare die contract with Atmel too.
Re: Does anyone have 15C LE dissection pics? - Kerem Kapkin (Silicon Valley, CA) - 09-22-2011 Packaged chips go through extensive relaibility and retention tests including at high temperatures. Sometime the defects are not detectible until a high temperature test is performed. However bare die only goes through a simple probbing test. Testing becomes much more complex and difficult once the bare SoC chip is sureface mounted on a board, and some tests such as high temperature testing are not possible.
Therefore I would argue that 15C could be more reliable than 12C at least as far as the reliability of the SoC is concerned.
Re: Does anyone have 15C LE dissection pics? - uhmgawa - 09-22-2011 Quote:
Possibly, but I believe the answer is only known to HP.
Quote:
Apparently they do but through specialized die distributors
Re: Does anyone have 15C LE dissection pics? - sylvandb - 09-22-2011 Quote: speculation follows... The lqfp might be the new design/layout. Has anyone opened a recent 12c (30th AE or similar vintage) to see if it is still using the COB? Perhaps the bare chip contract ended, and rather than extend it the board was redesigned for the lqfp. Maybe the lqfp price was near enough the COB not to matter? Maybe the 12c volume has declined so that the COB was no longer justified/cost-effective?
Re: Does anyone have 15C LE dissection pics? - Eric Smith - 09-22-2011 Quote: I stated that, less precisely. However, they don't add very much to the manufacturing cost, because the ODM in China is already equipped to do all of that, and does it routinely for many products. This is why if you open up just almost any sub-$50 electronic item, you'll find that it uses CoB assembly. SMT assembly in low-cost items is the exception.
This is what makes it particularly bizarre that the 15C LE has moved to SMT assembly.
Re: Does anyone have 15C LE dissection pics? - Mike Morrow - 09-22-2011 Quote:
An interesting (to me) example of that is the Casio fx-115/991ES. It has a 204-connection chip die under the black epoxy blob, most of which go to the 31x96 dot-matrix LCD with 18 annunciators (2994 elements). It sells for less than $13 at some US major retailers.
Re: Does anyone have 15C LE dissection pics? - uhmgawa - 09-22-2011 Quote:
Most contemporary graphic lcd controllers of such density are Re: Does anyone have 15C LE dissection pics? - Paul Dale - 09-23-2011 We've not experimented but this possibility has been mentioned :-)
- Pauli
Re: Does anyone have 15C LE dissection pics? - Marcus von Cube, Germany - 09-23-2011 This opens up opportunities to connect the missing JTAG connector and crystal for repurposing.
Re: Does anyone have 15C LE dissection pics? - Katie Wasserman - 09-23-2011 Yes it does if you're good at doing some very precise soldering, it's a 0.5mm lead pitch.
Re: Does anyone have 15C LE dissection pics? - uhmgawa - 09-24-2011 Quote:
0.5mm pitch gull wing packages aren't too formidable.
Alternatively (judging from the autopsy above) the 15c le as Re: Does anyone have 15C LE dissection pics? - uhmgawa - 09-24-2011 Quote:
After a chat with an Atmel die reseller today it isn't quite
No idea if any of the above applies to the 15c le's manufacturing |