Questions about SX vs. Stamps
sealion99
Posts: 23
Hi,
I am trying to make a decision about getting a microcontroller for hobby work (control experimentation, datalogging, robotics, etc.).· I am an EE with lots of industrial SW development experience so I really want something that will provide me with lots of technical features and options.· I've used basic stamps in the past and had good luck with them, so I started looking at the current Stamp options.· The BS2p40 seems to offer quite a bit and I had pretty much decided to go ahead with that chip before I started looking at the SX options.· One of the biggest problems I have with the BS2p40 is that Parallax appears to be discontinuing most of the development board options that can be used with it.· About the only board option that is left is the Professional Development Board, which is nice but also very expensive.· I'm really not sure the reasoning behind that, but it does not make me feel too good.· Does anyone know why this is happening?· Is something new coming out to replace, or is the bare SX the replacement??
Regarding the SX, I'm a little confused about the architecture and how to compare it with the Stamps correctly.· I understand that the SX chips·are used in most of the Stamps, but·they are fairly hidden.· Given the published info,·it seems like the SX48BD makes the most sense for me.· However, I wish they offered it in a DIP package, but that is not too big of an issue for me.· The ability to run it at fast clock speeds, and the standard 36 I/O points makes it quite interesting.· The fact that it can interface with I2C and one-wire devices is also something that I want to have.· Does anyone know if the BS2p's support for I2C and one-wire interfacing is implemented via VPs or is it a physical HW interface?· I'm not too sure about VPs vs. having direct hardware support.· What are the +'s/-'s regarding VPs?· What type of performance issues do VPs introduce?· Since alot of the communication abilities of the SX are handled via VPs, how does that affect its performance?· Due to the architecture differences, I'm having trouble trying to understand the actual performance differences between the SX48BD and the BS2p40.· If anyone has any information, I'd appreciate it it you would share it.
Memory is another area that I would like to be more clear about.· The memory options for the Stamps are given in terms of the number of instructions they can contain.· This type of information is not provided for the SXs.· I am assuming that this is due to the differences in the way code is compiled in the SXs.· Does anyone have info regarding the approx. number of lines of code that can the SXs can handle?· I am assuming that this is larger then the BS2's, is that correct?· Are there any other memory related issues with the SX that should be considered?
I appreciate any help that can be provided.·
Thanks,
Chris
I am trying to make a decision about getting a microcontroller for hobby work (control experimentation, datalogging, robotics, etc.).· I am an EE with lots of industrial SW development experience so I really want something that will provide me with lots of technical features and options.· I've used basic stamps in the past and had good luck with them, so I started looking at the current Stamp options.· The BS2p40 seems to offer quite a bit and I had pretty much decided to go ahead with that chip before I started looking at the SX options.· One of the biggest problems I have with the BS2p40 is that Parallax appears to be discontinuing most of the development board options that can be used with it.· About the only board option that is left is the Professional Development Board, which is nice but also very expensive.· I'm really not sure the reasoning behind that, but it does not make me feel too good.· Does anyone know why this is happening?· Is something new coming out to replace, or is the bare SX the replacement??
Regarding the SX, I'm a little confused about the architecture and how to compare it with the Stamps correctly.· I understand that the SX chips·are used in most of the Stamps, but·they are fairly hidden.· Given the published info,·it seems like the SX48BD makes the most sense for me.· However, I wish they offered it in a DIP package, but that is not too big of an issue for me.· The ability to run it at fast clock speeds, and the standard 36 I/O points makes it quite interesting.· The fact that it can interface with I2C and one-wire devices is also something that I want to have.· Does anyone know if the BS2p's support for I2C and one-wire interfacing is implemented via VPs or is it a physical HW interface?· I'm not too sure about VPs vs. having direct hardware support.· What are the +'s/-'s regarding VPs?· What type of performance issues do VPs introduce?· Since alot of the communication abilities of the SX are handled via VPs, how does that affect its performance?· Due to the architecture differences, I'm having trouble trying to understand the actual performance differences between the SX48BD and the BS2p40.· If anyone has any information, I'd appreciate it it you would share it.
Memory is another area that I would like to be more clear about.· The memory options for the Stamps are given in terms of the number of instructions they can contain.· This type of information is not provided for the SXs.· I am assuming that this is due to the differences in the way code is compiled in the SXs.· Does anyone have info regarding the approx. number of lines of code that can the SXs can handle?· I am assuming that this is larger then the BS2's, is that correct?· Are there any other memory related issues with the SX that should be considered?
I appreciate any help that can be provided.·
Thanks,
Chris
Comments
From my reading it looks like SX/B programming isn't that different from PBASIC. That's about all I can tell you as I am still in process of getting an SX to make the switch.
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NerdMaster
For
Life
In regards to a DIP module for the SX48 there is one in the works and the final PCB's are on order. They should be in within a few weeks. The finished module is pin compatible with the BS2p40 but for programming has a 4-pin header where you plug in either an SX-Key or SX-Blitz. You can see a picture of the prototype and read about the progress on the following thread:
http://forums.parallax.com/forums/default.aspx?f=7&m=166781
The DIP format lends itself well to just working on a reagular breadboard. I just use that method myself as I don't have one of the professional development boards. Either way works fine. What's nice about this new SX48 module is that it should also work on the Professional development board or plug right in to any board that is already setup to accept a BS2p40. Depending upon what you're doing the SX48 can be a step up in performance since you write in SX/B (compiled BASIC similair to PBASIC), assembly, or a combination of both. Having direct access to interrupts is also a plus. The SX48 has on chip flash for program/data storage and a bit of ram for variables. If you need more memory you can use external EEPROMs and other devices but mainly for data storage. I don't believe you can have a larger program and store program code outside the chip though.
At the moment I was only looking at having these modules as kits which will help introduce surface mount soldering.
I do like the Stamps, the SX series, and the propeller. I'm finding uses for each of them in different projects.
I'm sure many others can add more details as to the pros and cons of each one of the processor chips. I just wanted to at least mention that if you do consider the SX route that there should be a DIP module for it in the near future.
Good luck on your projects,
Robert