HC705K1 Replacement Recomendation

[Rodo55]

Hello Everyone,

I’ve been in electronics for a while but I haven’t had the opportunity to work with MCU’S. I have a friend that had a device made for him several years ago with a HC705K1 controller and he has asked me if I would fix/update it. Since HC705’s are not supported very well and they’re getting harder to come by and he wants to add new features I thought an updated MCU would be warranted. I have an associate that has worked with the HC908QY4 and he recommends using it. What I have found is the HC908’s are also coming to their end of life so I hesitate using it. The MCU that looks like it might be good for the application is the MC9S08QG4/8. I can use the A/D converters, internal oscillator, easy programming, etc… to simplify the circuitry.

I’d like to ask users for their advice on a couple of things:

Is the HC908QY2/4 outdated and if so what would be a more up to date replacement for the HC705K1 or HC908QY2/4. Would the MC9S08QG4/8 be a good choice?

Based on a recommended replacement what should I get to write and test code for the application. Or what would be a good development package? It looks like the DEMO9S08QG8E would be a good choice if the MC9S08 was an up to date replacement. It doesn’t look like the DEMO9S08QGE ($50 Digi-Key) comes with software so I think CodeWarrior would be an option?

I know most of you probably hate newbie’s since we can ask stupid questions but I have searched the forums and I don’t see where a newbie like me can get information on replacements for older MCU’s. Also I didn’t find recommendations on specific equipment to get started with a particular MCU. Once the selection is made I think I’ll be OK.

Maybe I didn’t find the getting started forum, is there one? If these questions have been answered elsewhere please point me to the right forum and I’ll check it out.

Any advice is welcome even if it’s hey look over there.

Thanks, Rodo

[RickN]

Hi Rodo,

    It appears that the 9S08QG8 16 PDIP is pin compatible with the 9S08QE8 16 PDIP, so you could buy the DEMO9S08QG8 and swap out the QG8 for a QE8 16 PDIP. 

    Just a thought.

    - Rick

[Rodo55]

Thanks Rick,

I didn't notice they were pin compatible as I was reading all the information.

I think that is an excellent idea.

I’ll do that.

I think I’ll follow Jim’s advice and start working with some SMT stuff too. I've got a good SMT soldering station so that's a step in the right direction but I need to get a microscope. I think that's why I've been hesitating getting into SMT. I get frustrated everytime I have to work SMT circuit boards. Probably because I couldn't see it well enough to do a good job. Maybe the micrscope is my answer.

But to get this project on the road I’ll buy the DEMO9S08QG8 and swap the MCU. Baby steps you know. :smileyhappy:

Thanks everyone again,

Rodo

[RobG]

Hi Rodo,

I'm wondering if the system you want the replacement for is running on 5 Volts. If so a better option might be the new 9S08SHx which will run on 5 Volts. The 9S08QGx is 3.6 Volt max.

Rob

[JimDon]

Rob,
Could you explain this small but persistent obsession with 5Vs?
I starting in engineering the the 1970's when 5Vs was king, but I can not find anything I can't do with 3Vs, including driving 5V devices.(for a few bucks you can add a 3v to 5v charge pump if needs be).
As we move in to the future, most everything will be 3vs.

I don't get it.

[RobG]

Jim,

You want someone who IS obsessed by 5 Volts to debate this with you. I have both 3 Volt and 5 Volt MCU based products. I'm guna sit on the fence.

Rob

[JimDon]

Rob,
Well really, I want a dialog so I can understand their problems an perhaps offer soultions.
It' really not subject to debate, either you can get a workable soultion or you can't.
The things is 3V and below is where we are headed, or perhaps where we are.

[Rodo55]

Thanks Don and Rob for your feedback I appreciate it.

Rob is correct that the original design is a 5v implementation which would allow me to keep a lot of the original layout if I used a 5v MCU. This could save me a lot of redesign time if I stay with the 5v layout.

Don is correct that the future is looking like the 3v MCU’s will be the main stay.  It would also allow for longer battery life but it will require a lot more up front redesign work.

So, I have more to think through but I do appreciate your help on getting me heading in the right direction with MCU options and development tools.

Also, being a little old school I do like the idea of a PDIP package just because that’s what I’m used to. I do own a SMD rework station but as an old dog it’s hard to change, especially when my eyes are not as good and my hands aren’t as steady as they used to be. But if I want to continue to work/play in the electronics world I guess I should look at the SMT world a little closer to keep up. From reading all the forums I’m probably the last one to move to the MCU technology anyways.

Thanks Again,

Rodo

[Rodo55]

Well, I think I’ve decided to go with the MC9S08QE8CPG which is a QE family member and has a 16 pin PDIP connection. This will allow me to jump into MCU development yet keeping me within some of my comfort zone with PDIP. The trouble is I am unable to locate a development board that’s compatible with it.?

The DEMO9S08QE8 seems like it would be the board to use but The DEMO9S08QE8 documentation says it’s only compatible with the MC9S08QE8CLC and the DEMOQE128 doesn’t seem to be compatible with anything other than the 128’s. What I don’t see is a PDIP daughter board for the DEMO9S08QE8. Is that still true?

Does anyone know of a demo/development board compatible with the MC9S08QE8CPG 16 pin PDIP package?  If there isn’t a PDIP compatible daughter board is there another DEMO board that will work?

What is the next easiest package to work with if the PDIP isn’t an option?

Maybe go with the MC9S08QG8 and its demo board if the QE8 family doesn’t work out

Thanks again for your help.

Rodo

[Rodo55]

I meant to say, Thanks Jim and Rob.

Sorry Jim, I don't why I got hung up on calling you Don.

[JimDon]

No problem.

I'm an old dog too, and I recently made the jump to SMT.

There were two tools that I purchased that made it possible - a used microscope and a used JBC Solder iron. the old Weller just didn't cut it. I paid about 350 for a Nikon stereo zoom and 180 for the solder iron.
The JBC is like 10 years old but works perfectly - it's an amazing unit the tip comes up to full temperature in 3 seconds - not "like 3 seconds" really 3 seconds . The Nikon is probably even older, but it works like a charm.

If you don't go beyond 32 or maybe 64 LQFP and your eye sight is good, you might get buy with one of  those magnifiers on an arm, but I love the Nikon.

I also have a pair  of used JBC hot tweezers, which are pretty handy as well. A hot air gun is fine though.
JBC equipment is pricey, but it works perfectly and forever.

Also, SMT is less expensive to have assembled. If you limit your self to DIP and 5V you will have less selection.

There is a good chance you could double battery life. "stop" mode currents are quite often measured in nano amps and run currents are very low.

[JimDon]

Hi Rodo and welcome.

I 100% agree that you want to move into the HCS Family.
The debugging is much better and the selection is awsome.

The DEMO9S08QG is not a bad choice, but you should also look at DEMOQE128. The QE Family is the newest one and starts with a 1.00 8 bit 4K part and goes up to a 32 bit 128K (and shortly beyond, WAY beyond). The 8 and 32 bit parts are 100% pin compatible and device compatible (meaning the I/O blocks work the same) and the Codewarrior tools allow for easy porting between the parts.  The QE Family is also low power enabled.

DEMOQE128 is 49.00, and comes with both an 8 bit and 32 bit daughter card. Digikey has it stock.
Also some cool toys on the board like an accelerometer.

Here is a link to the Flexis QE Family.

If you are at all interested in having USB in the product, another great demo board is the DEMOJMSKT.
This is also part of the Flexis Family but has USB on board and is also 8/32 bit.

Here is a link to the JM Flexis Family.

In all cases, the demo board can be used as a BDM for your prototype boards as well.

Code Warrior Special Edition is a free down load and is good to 32K for the 8 bit part and 64K for the 32 bit part. It also has a cool feature called Processor Expert that helps to set up all the registers and will put device drivers into your project.

And if you have any problems, you will have help here.