HP-25C Eumulator

[Mark Hardman]

(11-18-2014 03:43 AM)Chris Chung Wrote:  Looks like we are set for another batch.

The cost again is CAN $30 for kit, $40 assembled. Shipping for each unit is $3.00 Canada, $5.00 US, $8.00 elsewhere.

I will be using the V0 screen silk (see below) and it resembles the HP-25 key legends (except those symbols I cannot reproduce).

Please add me to the list for an assembled V3 board.

Thanks again!

[Didier Lachieze]

(11-18-2014 12:43 PM)Chris Chung Wrote:  

(11-18-2014 08:33 AM)Didier Lachieze Wrote:  Please count me in also. A kit would be fine for me.

The project is all thru-hole parts. But to conserve space, it's a double sized zigzag layout (like a back-split house) and will require cutting down some component pins during assembly. Also the tactile button spaces are rather tight and a thin tip temperature controlled iron will work better. Please watch my video (which includes construction) on the top post. You may decide to take a kit or assembled when we have the parts available.

OK, I have seen the video and I have the soldering equipment. I think it should be fun to assemble the kit but we'll see when the parts will be available. Thanks for this project anyway

[Namir]

(11-18-2014 05:35 PM)Mark Hardman Wrote:  

(11-18-2014 03:43 AM)Chris Chung Wrote:  Looks like we are set for another batch.

The cost again is CAN $30 for kit, $40 assembled. Shipping for each unit is $3.00 Canada, $5.00 US, $8.00 elsewhere.

I will be using the V0 screen silk (see below) and it resembles the HP-25 key legends (except those symbols I cannot reproduce).

Please add me to the list for an assembled V3 board.

Thanks again!

Count me in for two assembled units.

Thanks!

Namir

[Chris Chung]

Hi All,

Guenter, BobVA 1or2?, EdS2, Nigel, Namir X2, Didier, Mr. J, Mark.

It appears we will have 9 or 10 units for V3, and a typical batch is 10 units.

I am closing this batch for now, I have 2 pending orders of V2 (waiting for buttons and 74HC164s) which I will ask if they want the option to move to a V3 board.

If other members are interested (or just saw this thread and also want one), please do indicate in this thread. There will be 1 to a few spares extras in the end. Sometimes my PCB fab will throw in 1 or 2 extras boards that they had used as testers and they are as good.

/EDITED, forgot Mr. J via PM

[John R]

(11-19-2014 01:43 PM)Chris Chung Wrote:  If other members are interested (or just saw this thread and also want one), please do indicate in this thread. There will be 1 to a few spares extras in the end. Sometimes my PCB fab will throw in 1 or 2 extras boards that they had used as testers and they are as good.
/EDITED, forgot Mr. J via PM

If it's not too late, I'll take one assembled unit too. Thanks!

[Chris Chung]

Updated list.

Mr. H, Guenter, BobVA 1or2?, EdS2, Nigel, Namir X2, Didier, Mr. J, Mark (10 or 11)

Extra board wait list

John.

(11-19-2014 05:31 PM)John R Wrote:  If it's not too late, I'll take one assembled unit too. Thanks!

It is likely (9 out of 10 times) that I will get 1 or 2 extra boards per fab. Otherwise you could be in another batch.

I do not want to order 20 boards at a time because this is a newer design and there is always risks that I (or the fabrication house) make mistakes.

For all, please don't worry about payment. I will PM individual members for shipping address and paypal arrangements when the unit / kits are ready.

[SlideRule]

(11-18-2014 03:43 AM)Chris Chung Wrote:  Looks like we are set for another batch.

Chris

Count me in for a version 3 release.

SlideRule

[BobVA]

(11-19-2014 01:43 PM)Chris Chung Wrote:  Hi All,
BobVA 1or2?

Two, please!

Bob

[brouhaha]

I'd also like to get two of the next batch. Thanks!

[PANAMATIK]

There is another one for me, please.
Thanks too!

[Chris Chung]

Progress and group-buy update.

V3 pcb list
Mr. H, Guenter, BobVA X2, EdS2, Nigel, Namir X2, Didier, Mr. J, Mark (11)

Extra board wait list
John, Brouhaha X2, PANAMATIK (4)

I had submitted the design to my fab house and they had checked it (very quick) and it's in production. Usually it will take another 20 days before it reaches me. Again this batch is 10 boards only. When I received them, I will build immediately and if there are no major issues, I will ask for another 10 boards.

I toyed w/ a V0 pcb yesterday and produced a kit-test unit. It will be helping me to test led modules, 74HC164s and the MSP430G2533 MCUs. For kit orders, I will test all these major components before shipping them out. The V0 boards have some wrong traces and I have to run a couple of wires over them.

It has the low-profile keys that we will be getting on the V3 board, the benefit being that the key legends will be more visible from different angles. The keys will be however lighter to the click, but still a firm click.



This is the back-side, I had IC sockets for component testing, the led modules can be friction fitted (they have thicker pins) for testing. If you plan to use IC sockets, you should get the "machined pin" ones (round) instead of these cheap ones. I only have these on-hand.

[Didier Lachieze]

The legends with the low-profile keys look very good !

(11-20-2014 03:03 PM)Chris Chung Wrote:  If you plan to use IC sockets, you should get the "machined pin" ones (round) instead of these cheap ones.

Do you have any reference example for these ?

[Chris Chung]

(11-20-2014 03:42 PM)Didier Lachieze Wrote:  The legends with the low-profile keys look very good !

Yes, I am surprised that the whole thing is so much lighter too! May be I can send it as Letter mail. It's just that there is no easy (and cheap) way to do multi-color silk-screen prints as they use special inks. Otherwise it would be much prettier.

Quote:

(11-20-2014 03:03 PM)Chris Chung Wrote:  If you plan to use IC sockets, you should get the "machined pin" ones (round) instead of these cheap ones.

Do you have any reference example for these ?

It's just for kit builders who want to have sockets.

The socket w/ the rounded pins are machined. It does not matter much on all digital circuits. But for analog circuitry it may affect performance. In my design I use a RC delay trick to push bits into the 74HC164 shift register (for led segments). I need it to save one IO pin. And the cheaper sockets can affect the RC timing.


I had previous head-scratches during prototyping when things works w/o socket and fails w/ socket.
Actually if I use a Atmel mega328/168 (28 pins), the circuit will be cleaner and reduce to just 1 IC (no shift register needed). But I haven't use AVRs for quite awhile now and it's more interesting to do it w/ an MSP430.

[Harald]

(11-20-2014 04:10 PM)Chris Chung Wrote:  Actually if I use a Atmel mega328/168 (28 pins), the circuit will be cleaner and reduce to just 1 IC (no shift register needed). But I haven't use AVRs for quite awhile now and it's more interesting to do it w/ an MSP430.

Why not use the MSP430G2533IPW28? That has 28 pins as well. I thought about doing that, but to be honest so far I didn't even find the time to look at the datasheet...

Edit:
I just had another look, the demoboard comes with an MSP430G2553. Your code also says 2553, but in your post you mention 2533. I haven't got your board handy to check, but I guess its the 2553. Anyhow, the differences appear to be minute and the 2553 is available as a 28 pin device too.

[Chris Chung]

(11-25-2014 03:55 PM)Harald Wrote:  

(11-20-2014 04:10 PM)Chris Chung Wrote:  Actually if I use a Atmel mega328/168 (28 pins), the circuit will be cleaner and reduce to just 1 IC (no shift register needed). But I haven't use AVRs for quite awhile now and it's more interesting to do it w/ an MSP430.

Why not use the MSP430G2533IPW28? That has 28 pins as well. I thought about doing that, but to be honest so far I didn't even find the time to look at the datasheet...

Edit:
I just had another look, the demoboard comes with an MSP430G2553. Your code also says 2553, but in your post you mention 2533. I haven't got your board handy to check, but I guess its the 2553. Anyhow, the differences appear to be minute and the 2553 is available as a 28 pin device too.

I started w/ 2553 (adc + comparator) since it comes w/ the launchpad and I had lots of it. When I order for kits I get the 2533 (adc only) as it's more available and less expensive. The project only requires a 2513 (no adc nor comparator).

The 2553 has all the peripherals but in our case, we only need IO pins for led multiplexing and key scanning.

As for the 28 pin devices, they are only available on TSSOP packages. If we use one of these, it will be a one chip design as we will have enough IO pins to drive everything. I.e. no 74LS164 and the tricky one-line shifting. It just happened that I am more inclined to use DIP devices as it's easier to build for everyone. /EDIT Also I think DIP device looks better in a retro project /END-EDIT. Now that I look again, a TSSOP is not too bad to hand solder except that it is not commonly carried by my usual supplier (newark.com) and could be harder to get.

If I am to do it again, I would move to a F2274 (38 pin tssop) and I will be able to to fit another HP-34C inside w/ doubled flash and RAM.

There are many improvement possibilities, like instead of shut-off, we could make the MCU deep sleep at LPM4 (low-power-mode 4) and have RAM retention (continuous memory), the MSP430 at this mode consumes only 0.1uA.

[Namir]

Chris,

How difficult will it be to add subroutine support (at least one level). You will need to commands: GSB and RTN. The GSB can refer to a line-number. There are two keys with no shift functions and that's where the GSB ad RTN commands can be located on the keyboard. Even a single-level subroutine will greatly enhance the programming features of the HP-25.

Namir

[Chris Chung]

(11-26-2014 10:41 PM)Namir Wrote:  Chris,

How difficult will it be to add subroutine support (at least one level). You will need to commands: GSB and RTN. The GSB can refer to a line-number. There are two keys with no shift functions and that's where the GSB ad RTN commands can be located on the keyboard. Even a single-level subroutine will greatly enhance the programming features of the HP-25.

Namir

Wouldn't that make a HP-33C. It's already included! There are 3 ROMs inside the unit, 21, 25C and 33C and you can switch between them. The silkscreen, however, was done as if it's a HP-25C (more popular). May be one can try and make overlays for other models. This the the most powerful MSP430 MCU in DIP package. If we want to also emulate 34C, I will have to move to SMT devices.

Here is a simple operation tutorial (posted earlier, in case you miss it)
http://youtu.be/0bu46mYKqck

[Namir]

(11-27-2014 12:24 AM)Chris Chung Wrote:  

(11-26-2014 10:41 PM)Namir Wrote:  Chris,

How difficult will it be to add subroutine support (at least one level). You will need to commands: GSB and RTN. The GSB can refer to a line-number. There are two keys with no shift functions and that's where the GSB ad RTN commands can be located on the keyboard. Even a single-level subroutine will greatly enhance the programming features of the HP-25.

Namir

Wouldn't that make a HP-33C. It's already included! There are 3 ROMs inside the unit, 21, 25C and 33C and you can switch between them. The silkscreen, however, was done as if it's a HP-25C (more popular). May be one can try and make overlays for other models. This the the most powerful MSP430 MCU in DIP package. If we want to also emulate 34C, I will have to move to SMT devices.

Here is a simple operation tutorial (posted earlier, in case you miss it)
http://youtu.be/0bu46mYKqck

Sorry I missed that fact. No need to add the GSB since the hardware emulates the HP-33C. Thanks for the YouTube link. The video is nice!

Namir

[Didier Lachieze]

(11-27-2014 12:24 AM)Chris Chung Wrote:  This the the most powerful MSP430 MCU in DIP package. If we want to also emulate 34C, I will have to move to SMT devices.

I would like to have a 34C dedicated version in addition to the 21/25C/33C current one.

[Chris Chung]

(11-27-2014 07:31 AM)Didier Lachieze Wrote:  

(11-27-2014 12:24 AM)Chris Chung Wrote:  This the the most powerful MSP430 MCU in DIP package. If we want to also emulate 34C, I will have to move to SMT devices.

I would like to have a 34C dedicated version in addition to the 21/25C/33C current one.

The current hardware design does not allow for that. At most, one can replace the 3 ROMs (21/25C/33C) w/ a single 34C ROM with minor software modification. And due to the limited RAM the MSP430G25x3 provides, there will not be full programming steps available.

Replacing the G25x3 w/ a more potent F2274 MCU will allow for 4 ROMs plus enough RAMs for a 34C emulation. It will also eliminate the need for the 74HC164 shift register. This requires a re-design hardware and quite a bit of changes on the software (mostly LED driving). This design exists only on my head and I am not planning to work on it right now as there are other interesting projects for me. I will however work on a reduce 34C firmware that runs on the current PCB later on. If you have a unit it is a good idea to find out how to acquire firmware flashing capability so that you can flash new / patched firmware in the future. I had mentioned how (and what's needed) this can be done in previous posts.