In SX Microcontrollers, SX/B Compiler and SX-Key Tool, g_daubach wrote:

The primary idea when I designed the SX Multi Board was to create a board useful for various SX 28 applications, not primarily to be used as a prototype board. Besides the usual parts around the SX, like a resonator, a parallel resistor, a reset circuit, the pull-up for the RTCC input, and the SX-Key header, a MAX 232 level shifter with its components and a SUB-D 9 jack (the "RS-232 section"), a TO 220 packaged voltage regulator with its components (the "Regulator Section") may be installed. There are also places for a 4-pin header (I²C), jumpered I²C pull-up resistors, a 6-pin Header (serial TTL port), and for two resistors and a capacitor to be used for ADC/DAC purposes. All important SX oins are also available on e 2*13 pin header. When installed on the solder side, it may be used to "piggy-back" the board on top uf another PCB, or - when installed on the component side - for a ribbon cable connector.

So, the  the SX 28 Multi-Board can be used for applications in small series where a dedicated PCB design would be too expensive, or for the pre-series of a larger application. I recently used it exactly for this purpose to build an evaluation sample for one of my customers. Now, that this application is going into series production, I have replaced the SX 28 Multi-Board by a PCB especially designed for this application. I'm also using it for my RS-232/I²C Adapter/Monitor, and for various motor controllers for concrete saws where it is sitting "piggy-backed" on top of a larger board. If not needed, the "RS-232" and the "Regulator-Sections" may be cut off which I did in case of the motor controllers in order to minimize used real estate on the main board. You may ask why I did not integrate the SX parts on the main board in this case. There are two reasons: The main board is a 2-layer board, so the 4-layer SX 28 Multi-Board provides aome better EMI protection. The second reason is ease of service. People who handle such boards are used to handle heavy machinery stuff, and not small DIL packages. In case of a software update, I feel much better having them replace the whole SX 28 Multi-Board instead of pulling out the SX 28 off its socket, and inserting a new one.

I too was thinking of having the board manufactured in the US - it simply depends on the sales figures. I think I should start sending boards in bulk to a US distributor (Parallax, may daughter, or someone else), and see how things develop.

Concerning the parts kit - as this is not a prototype board on first side, a full parts kit does not make much sense because which parts are really required depends on the specific application. Maybe, it makes sense to add a socket for the SX28, and the power connector as these parts may not be available in a shop around the corner. The SX28 and the resonator should be better acquired from Parallax instead of shipping them across the atlantic twice.

---------- End of Message ----------


You can view the post on-line at:
http://forums.parallax.com/forums/default.aspx?f=7&p=2&m=105106#m107035

Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com

The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2006 (http://www.dotNetBB.com)