My robot is better than your robot LOL.·Not to hijack this thread, I have a couple of RB5X robots. One of the robots, I was trying to refit using the SX52 proto board. ·I have come to the conclusion that the SX52 is not working out for me, so I will be going the Propeller route.
Things are looking good so far in regards to the module. The boards should be done in a few weeks. They will have a silkscreen on both sides to help with the installation of parts and also identifying each one of the pins. While i'm waiting for the boards I can work on the assembly instructions to make sure everything is clear. At the moment it looks like a full blown kit would be just under $40 (with machined pin headers for the sides, dip socket, EEPROM, resonator socket, and all parts) with the potential for discounts on multiple kits. I could also offer a bare bones version with just the processor, voltage regulator, etc for less. In either case it could be built as a 5v or 3.3v module by substituting a few parts. It should not affect the cost, just what parts get included with the kit.
I'll be posting updated here as things progress. Once I get my new website up they will be posted on their as well.
As an update I also wanted to note that the boards are being done Lead-free and all of the parts going into the kits are targeted at being RoHS compliant. Not that it may matter to those in the US but I think it will be important for anyone overseas.
I must admit however that I've recently tried the new RoHS comliant solder and i'm not fond of it. I don't know if it is just the brand I picked to try out or if it all acts differently. The final solder connection doesn't apear as shinny as it use to and doesn't quite flow the same. It works well enough but just something to get used to.... Perhaps other brands are better. If anyone here is using some RoHS solder and really likes it, please let me know what you are using.
Oh, and if anyone is curious the boards are going to be blue with white silkscreens. They should look cool.
I hate this new RoHS solder! I don't think it depends on the brand you are using. I have tried various brands but such solder joints always look ugly, i.e. not as shiny as you are used to, and you need higher temperatures to make it flow.
And the RoHS white tin plating is dreadful too, has a shelf life of 3 months or less and is very sensitive to body oil. Don't populate the board within a few months or accidentally touch a pad with a bare finger and say goodbye to the board because no amount of cajoling will make a component solder to the pad.
Well, let us all hope that they will come up with some new formulas for the plating and for the solder. I had hoped it was just the particular brand of solder I had been trying which acted odd but apparently not. For the time being I'll still use my good old leaded solder for my own personal projects and use up the RoHS stuff where I can.
That is a pretty scary thought about the white tin plating and the shelf life. Is that what they consider the Lead free solder finish?? I've seen several different finishes mentioned but not too many sites go into all the pros and cons of the different finishing options. This is the first i've heard about a shelf life for a PCB and it's a bit disturbing. Does that affect any rework? How about just how long a board will hold up under normal use?
I still have some old unpopulated PCB's for the Heathkit HERO's (some of which are nearly 25 years old) and they still solder fine whenever I need to build one up. It doesn't sound like that is the future of PCB's. Great, it will be just like the groecery store and everyone will need to start puttng a "Best if used by: xx/xx/xx" date on the package to ensure the boards are fresh. If they expire, on to the outlet store or make keychains out of em....
Thanks for the note. Perhaps someone that has worked with RoHS for a while and knows the ins and outs could start a separate thread in the general section like "RoHS and you", "RoHS for Dummies", or something along those lines....
I just now did some more reading on the topic and had thought that RoHS is mainly for overseas. It now appears that it may go into effect in the US starting in CA. Anyone else watching what is going on with it? How will this effect the electronics hobbyist?
White tin plating is the economical RoHS plating, spend a little more money and you can get gold flash which doesn't have the same issues, though it doesn't look like you are getting what you paid for because it still looks silver since the gold plating is so thin. Spend even more money and you can get ENIG (Electroless Nickel-Immersion Gold) which really looks like it's gold plated.
RobotWorkshop said...
How will this effect the electronics hobbyist?
If you take a look at the ICs over at www.jameco.com, many of them have two versions, with the non-RoHS costing less.·
Calif. mandated no-clean solder, water-clean solder, etc., but you can still find lots of 60/40 rosin-core.· I worked at a small-business in the 80s that had its own (leased) freon-bath to clean boards with, really made 'em shine, too.·
It's like SMD/SMT, that's the way industry is going and TI, NatSemi, Intel, etc. don't knock out ICs for us guys -- we get what's left.
·I have tried an SX28 together with a 24LC64 EEPROM, and a MAX3232 on my RS-232/I²C-Adapter, all powered at 3.3V without problems.
Which I would dearly love to be able to order in small quantities as I've said a few time in the past in private emails. Any chance you will make that item available (especially with a dealer discount for quantities?) I would be happy to PayPal you the money in advance.
I guess Guenther doesn't want to talk to me?
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---
James Newton, Host of SXList.com james at sxlist,com 1-619-652-0593 fax:1-208-279-8767
SX FAQ / Code / Tutorials / Documentation: http://www.sxlist.com Pick faster!
I just received the final boards in last night for the SX48 40-pin module. The boards look great! They are dark blue with a white silkscreen for the pin numbers / components and are easy to read. I was up late and built a pair of them. New pictures soon....
Here it is... A picture that shows the original prototype that started this whole thread and the final board. Also another with two different headers for the SX-Key. Every one of the I/O pins is labeled as well as all the component locations. I am cleaning up the schematics now and working on the docs on how to assemble the board and some of the different options on how it can be built. The MAX232 for the Serial port and EEPROM are optional parts that can be left off if desired. Also, if the EEPROM isn't needed a 4-pin header can be installed on one side to pickup +5v, ground, RA.0 and RA.1. It should be easy to use the onboard MAX232 as a bi-directional Serial port to a host PC and use the these other two lines for another or two transmit lines.
This is something that will be available as a full kit, perhaps partial kit, and bare boards for those that already have most of the other parts.
The clock can be set to the internal oscillator or an external resonator underneath. I've used 4Mhz and 20Mhz so far with good results. Still need to try out 50Mhz. No support for a 75Mhz oscillator but I suppose with some creative soldering someone would be able to mount one on it.
If you want to get one of these early and don't mind a couple bumps in the documentation (which will be cleaned up) I could get something together pretty quick.
Hi Robert,
These do look great! The blue color really makes a difference in appearance.
My DIP24 (just plain old green) final revision is scheduled for march 5.
Attached is my revision B that differs from the revision A I posted earlier·in that it
has a regulator onboard (5V/500mA). The final revision has port A dedicated
to the debug serial i/o and reset circuitry so it will plug directly
into a dip24 socket.
Robert,
Looks great. I can tell alot of work went into it.
Just my opinion, but I've always considered 20MHz to be the perfect speed for the SX (for general purpose stuff). Doesn't use too much power (like 50MHz), but has enough horsepower to get most anything acomplished. If you sell them assembled, I would suggest you use the 20MHz resonator.
Nice job.
Bean.
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Cheap used 4-digit LED display with driver IC·www.hc4led.com
Thanks for the feedback. Both of the assembled modules in the latest picture have a socket underneath the module so the resonator is removable. It can be left out or a resonator plugged in. That's the way I would do a kit or assemble them. It's pretty slick since the resonator lays neatly flat against the board.
I don't know if you can see it in the picture or not but if you look closely you will see there is an intentional solder bridge that was added after soldering the CPU to tie the RTCC connection to the ground pin next to it. There a pad next to it so the solder bridge can be moved if someone actually wants to use the RTCC input pin.
I received my final revision yesterday.
There are only 2 through-hole components (apart from the headers),
the regulator and the resonator(socket). The smd parts have fixed values
and provide the debug port on pins SOUT, SIN and ATN. ATN is special, if you pulse
the pc com port DTR, you can via software decide wether just to reset, or perform
some other action. The module resets itself by making pin ra.0 a low output.
This module can be directly inserted into any 24pin socket that also accepts
BS and Javelin. Besides I/O pins P0 to P15 ( RB and RD) there are 16 more I/O pins (RC and RE)
via two 2x5 headers.
That looks great! I'll have to keep that in mind if want to use the SX48 in anything that uses a standard 24-pin socket. Let us know when (and if) you make these available.
I think you may have a form factor there that will be beneficial to anyone wanting to experiment with an SX in place of an existing 24-pin micro-controller. What an easy upgrade path!
I have the first batch of kits ready! The docs themselves are complete and I should have the schematics wrapped up this evening.
A full deluxe kit with onboard MAX232, an extra 20Mhz resonator (to plug into the socket), and an EEPROM would run $39.95. For
those that are interested trying out one of these initial kits I would cover the shipping (within the US) I will also have blank boards
available and perhaps a barebones kit for those that just want a nice compact carrier PCB for their SX48 microcontroller chips.
I've attached a picture of the deluxe kit contents for those that want to see what parts are included.
If you'd like one of these just send me an e-mail at: rdoerr@bizserve.com
For those of you following this thread I wanted to add that the schematics are complete. The kit comes with the full schematics for the module as well as step by step instructions for assembly. The goal with the docs is to ensure that anyone attempting to build the kit will be successful and learn a few new techniques in the process!
I've had a couple people ask about these kits that are a bit leary about soldering the SX48 chip itself as it has the smallest leads of all the parts in the kit. If that is the case just let me know and I can pre-install that one chip o the board to help you get started. The rest of the parts will help get your confidence up working with surface mount parts and the perhaps if you get another kit down the road you can try soldering the SX48 as well. Soldering these parts is getting easier and i've gotten really good at putting the CPU's on the board. Hopefully others out there will have the same results.
I just sent $40 to your paypal for one. However, after reading the threads closer, I see that you have added a MAX232 and EPROM, etc. How different is this to a Parallax Protoboard. I am currently using a SX52 Protoboard but·wanted something that I can use on a solderless breadboard first to develop with (no soldering till the end).
I think this will work out well for you! The MAX232 and EEPROM are included but they are optional.
When they are installed they connect to port A. RA.0 and RA.1 are normally used for the EEPROM at loation U2. The pins are clearly marked on the silkscreen if you want to use them for something else. RA.2 is normally used as a Serial in (RX) and RA.3 as Serial out (TX) via the MAX232. They work great with the serial commands in SX/B.
All the other ports B, C, D, and E are brought out to the DIP headers and are clearly marked. The docs should cover everything pretty well and the schematics are included. I'll be glad to answer any questions about the kit that come up.
Thanks Robert. If I understand you right, you state that the EEPROM is optional as well as the MAX232.
Does that mean that I just don't solder them in place? OR can they be installed and if another external component such as a DS1302 Real Time Clock is added to RA.0 - 3, it will not matter if the EEPROM or MAX232 is soldered in place.
If you need to use RA.2 and RA.3 then you'll probably want to leave off the MAX232 for now (you won't need to install the four 1.0
caps either) If you only need one of those and can use RA.3 (TX line) then leaving the MAX232 onboard won't hurt a thing.
The EEPROM just plugs into a DIP socket. What you may want to do is mount your DS1302IC on a 8-pin machined pin DIP socket and just wire up the appropriate pins on that so you can plug in that or the EEPROM. I've just looked at the datasheet for the DS1302 and you'd just need to bend up leads 1,2,3, and 7. pins 2,3 can get you xtal, pin 1 a cap to pin 4. The whole little 8-pin DIP module plugs into the EEPROM socket. With that just add a small jumper from pin 7 to RA.3 on the MAX232 and you should be all set!
I just received (2) SX48 chips to experiment with. I was shocked to see how small they were. As I thought they would be similar to the SX52 (from my SX52 protoboard - got 2 more of them today too from Parallax). The SX52 is small but solderable - but the SX48 is extremely tiny as compared to the SX52.
How does one work with this? Is there a special socket or something or do you have to use this SX48 or a protoboard?
I have a radio shack 15 watt soldering iron with a thin tip - but not that thin to work with this chip (I don't think). See attachment. Getting a bit nervous.
How about soldering Radio Shack 30 gauge wire to each pin then running them to a solderless breadboard?
Sorry for all the questions - just thinking out loud in a panic. lol.
The tip doesn't need to be as fine as the pitch of the CPU. You'll find that the method of soldering all the pins and then going back afterward to clear off the excess with solder wick gives excellent results. Below are a few paragraphs from the assembly manual for the SX48 40-pin module:
"One of the most important aspects of assembly is the proper alignment of the components. Some people prefer to use a small dot of glue to hold each component in place while soldering. If this works out well for you, by all means use that method. Otherwise the following techniques give excellent results!
Before installing a surface mount component apply a small amount of solder to one of the pads on the PCB where the part is going to be installed. Then while warming the solder on that pad use the tweezers to set the part in place. You can do adjustments while the solder is still molten. If it takes too long, let the solder cool to ensure the part is not damaged by excessive heat. Once cool the joint can be warmed up again and the alignment can be adjusted until it is perfect. Before soldering any other joints on the part use the magnifying glass to verify that the alignment is ok.
Components installed on the top of the PCB:
Install the Parallax SX48BD/TQ CPU near the center of the PCB at location U1. Pin one of the CPU should be orientated toward the upper left of the board. There is a small mark on the silkscreen, which shows the location. The alignment of this part is critical. First, tin the iron and tack the CPU in place. Do not worry about solder bridges at the moment. Once it is aligned solder one of the pins on the opposite corner. Double check the alignment with the magnifying glass. If all is well proceed to solder the rest of the pins. Since the pitch is so close on these pins just solder each side without worrying about solder bridges and let it cool before doing the next. After the chip cools go back over each side with solder wick to remove the excess solder. This will remove most of the solder and leave just enough to make a proper connection. Repeat the process if solder bridges still exist. Be sure to let the chip cool between each side so the microcontroller will not be damaged by excessive heat. The results can be fantastic if you take your time."
Everything is step by step and shouldn't be too hard to follow. If anything comes up let me know.
I sent you a PM. I got my SX48 OEM module last night and had it together in a couple of hours (less a fault on my end).
All is working now on my SX48 module. I used a DEVICE SX48, OSCXT1, BOR42 instead of a DEVICE SX48, OSCXT2, BOR42 for the 20 MHz resonator that came with the kit.
As stated in your PM, it does require concentration and a steady hand but I did it. Above all you need a magnifying lense. I got a cheap one at Walmart in the hobby / crafts section that worked ok.
I used a 15w soldering iron from radio shack because of the low wattage and the only one they have with a sort of a narrower point on it. Solder wick is necessary too and the kit came with it. I also used a dot or two of super glue to align and place the chip. This helped alot.
Once this was done I carefully layed solder across every row of pins bridging them together and waited for it to cool a bit for a few seconds. Repeat on the other 3 sides. Then used the solder wick and mag lense to check remove excess solder and check for any solder bridges to be removed. It was easy once·I found a good method.
I really like it now that I can use this on my PDB or any solderless breadboard and not have to solder wires to a Protoboard just yet. That I will save for the finished project. The module is very nice for development.
Here are some pics of the 2 modules I have. I bought a couple of·extra boards·with a few necessary parts as an experiment module. I think my camera is starting to go on me which is surprising for a Sony.
As you can see the first one (complete) I messed up thinking the module did not work so I carefully unsoldered the SX48 but pin 2 lifted on the board. I was able to run a short jumper wire to the OSC pin from pin 2. The problem was not on the board but in my code when I installed the 20 MHz resonator (that comes with it) but had my DEVICE line wrong (e.g. OSCXT1 and supposed to be OSCXT2). I also did not solder in the included EEPROM and socket and did not solder in the MAX232 chip and caps (as I wanted access to RA.0 to RA.3). All is working great now.
The second module has only the necessary resistors and caps (no pins, no 5v regulator and cap, etc.) as it was meant for wire soldering. This one (after my 3rd practice - worked great first time - got my technique mastered - easier than I thought).
Thank you both for the kind words and I am glad you are pleased with your kits! I hope that it ends up being a good introduction for using and getting familiar with the surface mount parts.
I now have some 4Mhz resonators on hand and if someone would prefer that instead of the 20Mhz resonator just let me know and I can substitute that part. Also, the offer still stands for anyone who wants the SX48 pre-installed on the board that I can do that before it goes out.
If you don't need all the extra components the blank PCB is available and makes a nice compact carrier for the SX48 for small projects. Quantity discounts will be available if you'd like several boards or kits.
Comments
Ray
I'll be posting updated here as things progress. Once I get my new website up they will be posted on their as well.
Best Regards,
Robert
I must admit however that I've recently tried the new RoHS comliant solder and i'm not fond of it. I don't know if it is just the brand I picked to try out or if it all acts differently. The final solder connection doesn't apear as shinny as it use to and doesn't quite flow the same. It works well enough but just something to get used to.... Perhaps other brands are better. If anyone here is using some RoHS solder and really likes it, please let me know what you are using.
Oh, and if anyone is curious the boards are going to be blue with white silkscreens. They should look cool.
Robert
I hate this new RoHS solder! I don't think it depends on the brand you are using. I have tried various brands but such solder joints always look ugly, i.e. not as shiny as you are used to, and you need higher temperatures to make it flow.
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Greetings from Germany,
G
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Paul Baker
Propeller Applications Engineer
Parallax, Inc.
That is a pretty scary thought about the white tin plating and the shelf life. Is that what they consider the Lead free solder finish?? I've seen several different finishes mentioned but not too many sites go into all the pros and cons of the different finishing options. This is the first i've heard about a shelf life for a PCB and it's a bit disturbing. Does that affect any rework? How about just how long a board will hold up under normal use?
I still have some old unpopulated PCB's for the Heathkit HERO's (some of which are nearly 25 years old) and they still solder fine whenever I need to build one up. It doesn't sound like that is the future of PCB's. Great, it will be just like the groecery store and everyone will need to start puttng a "Best if used by: xx/xx/xx" date on the package to ensure the boards are fresh. If they expire, on to the outlet store or make keychains out of em....
Thanks for the note. Perhaps someone that has worked with RoHS for a while and knows the ins and outs could start a separate thread in the general section like "RoHS and you", "RoHS for Dummies", or something along those lines....
I just now did some more reading on the topic and had thought that RoHS is mainly for overseas. It now appears that it may go into effect in the US starting in CA. Anyone else watching what is going on with it? How will this effect the electronics hobbyist?
Robert
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Paul Baker
Propeller Applications Engineer
Parallax, Inc.
Calif. mandated no-clean solder, water-clean solder, etc., but you can still find lots of 60/40 rosin-core.· I worked at a small-business in the 80s that had its own (leased) freon-bath to clean boards with, really made 'em shine, too.·
It's like SMD/SMT, that's the way industry is going and TI, NatSemi, Intel, etc. don't knock out ICs for us guys -- we get what's left.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
---
James Newton, Host of SXList.com
james at sxlist,com 1-619-652-0593 fax:1-208-279-8767
SX FAQ / Code / Tutorials / Documentation:
http://www.sxlist.com Pick faster!
Best Regards,
Robert
This is something that will be available as a full kit, perhaps partial kit, and bare boards for those that already have most of the other parts.
The clock can be set to the internal oscillator or an external resonator underneath. I've used 4Mhz and 20Mhz so far with good results. Still need to try out 50Mhz. No support for a 75Mhz oscillator but I suppose with some creative soldering someone would be able to mount one on it.
If you want to get one of these early and don't mind a couple bumps in the documentation (which will be cleaned up) I could get something together pretty quick.
Best Regards,
Robert
These do look great! The blue color really makes a difference in appearance.
My DIP24 (just plain old green) final revision is scheduled for march 5.
Attached is my revision B that differs from the revision A I posted earlier·in that it
has a regulator onboard (5V/500mA). The final revision has port A dedicated
to the debug serial i/o and reset circuitry so it will plug directly
into a dip24 socket.
regards peter
Looks great. I can tell alot of work went into it.
Just my opinion, but I've always considered 20MHz to be the perfect speed for the SX (for general purpose stuff). Doesn't use too much power (like 50MHz), but has enough horsepower to get most anything acomplished. If you sell them assembled, I would suggest you use the 20MHz resonator.
Nice job.
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheap used 4-digit LED display with driver IC·www.hc4led.com
Low power SD Data Logger www.sddatalogger.com
SX-Video Display Modules www.sxvm.com
·
Now. Just to get going on those docs....
Robert
Robert
There are only 2 through-hole components (apart from the headers),
the regulator and the resonator(socket). The smd parts have fixed values
and provide the debug port on pins SOUT, SIN and ATN. ATN is special, if you pulse
the pc com port DTR, you can via software decide wether just to reset, or perform
some other action. The module resets itself by making pin ra.0 a low output.
This module can be directly inserted into any 24pin socket that also accepts
BS and Javelin. Besides I/O pins P0 to P15 ( RB and RD) there are 16 more I/O pins (RC and RE)
via two 2x5 headers.
regards peter
That looks great! I'll have to keep that in mind if want to use the SX48 in anything that uses a standard 24-pin socket. Let us know when (and if) you make these available.
Best Regards,
Robert
I think you may have a form factor there that will be beneficial to anyone wanting to experiment with an SX in place of an existing 24-pin micro-controller. What an easy upgrade path!
Good work.
- Sparks
I have the first batch of kits ready! The docs themselves are complete and I should have the schematics wrapped up this evening.
A full deluxe kit with onboard MAX232, an extra 20Mhz resonator (to plug into the socket), and an EEPROM would run $39.95. For
those that are interested trying out one of these initial kits I would cover the shipping (within the US) I will also have blank boards
available and perhaps a barebones kit for those that just want a nice compact carrier PCB for their SX48 microcontroller chips.
I've attached a picture of the deluxe kit contents for those that want to see what parts are included.
If you'd like one of these just send me an e-mail at: rdoerr@bizserve.com
Best Regards,
Robert
For those of you following this thread I wanted to add that the schematics are complete. The kit comes with the full schematics for the module as well as step by step instructions for assembly. The goal with the docs is to ensure that anyone attempting to build the kit will be successful and learn a few new techniques in the process!
I've had a couple people ask about these kits that are a bit leary about soldering the SX48 chip itself as it has the smallest leads of all the parts in the kit. If that is the case just let me know and I can pre-install that one chip o the board to help you get started. The rest of the parts will help get your confidence up working with surface mount parts and the perhaps if you get another kit down the road you can try soldering the SX48 as well. Soldering these parts is getting easier and i've gotten really good at putting the CPU's on the board. Hopefully others out there will have the same results.
Best Regards,
Robert
I just sent $40 to your paypal for one. However, after reading the threads closer, I see that you have added a MAX232 and EPROM, etc. How different is this to a Parallax Protoboard. I am currently using a SX52 Protoboard but·wanted something that I can use on a solderless breadboard first to develop with (no soldering till the end).
Good job!
I think this will work out well for you! The MAX232 and EEPROM are included but they are optional.
When they are installed they connect to port A. RA.0 and RA.1 are normally used for the EEPROM at loation U2. The pins are clearly marked on the silkscreen if you want to use them for something else. RA.2 is normally used as a Serial in (RX) and RA.3 as Serial out (TX) via the MAX232. They work great with the serial commands in SX/B.
All the other ports B, C, D, and E are brought out to the DIP headers and are clearly marked. The docs should cover everything pretty well and the schematics are included. I'll be glad to answer any questions about the kit that come up.
Best Regards,
Robert
Does that mean that I just don't solder them in place? OR can they be installed and if another external component such as a DS1302 Real Time Clock is added to RA.0 - 3, it will not matter if the EEPROM or MAX232 is soldered in place.
caps either) If you only need one of those and can use RA.3 (TX line) then leaving the MAX232 onboard won't hurt a thing.
The EEPROM just plugs into a DIP socket. What you may want to do is mount your DS1302IC on a 8-pin machined pin DIP socket and just wire up the appropriate pins on that so you can plug in that or the EEPROM. I've just looked at the datasheet for the DS1302 and you'd just need to bend up leads 1,2,3, and 7. pins 2,3 can get you xtal, pin 1 a cap to pin 4. The whole little 8-pin DIP module plugs into the EEPROM socket. With that just add a small jumper from pin 7 to RA.3 on the MAX232 and you should be all set!
Robert
How does one work with this? Is there a special socket or something or do you have to use this SX48 or a protoboard?
I have a radio shack 15 watt soldering iron with a thin tip - but not that thin to work with this chip (I don't think). See attachment. Getting a bit nervous.
How about soldering Radio Shack 30 gauge wire to each pin then running them to a solderless breadboard?
Sorry for all the questions - just thinking out loud in a panic. lol.
The tip doesn't need to be as fine as the pitch of the CPU. You'll find that the method of soldering all the pins and then going back afterward to clear off the excess with solder wick gives excellent results. Below are a few paragraphs from the assembly manual for the SX48 40-pin module:
"One of the most important aspects of assembly is the proper alignment of the components. Some people prefer to use a small dot of glue to hold each component in place while soldering. If this works out well for you, by all means use that method. Otherwise the following techniques give excellent results!
Before installing a surface mount component apply a small amount of solder to one of the pads on the PCB where the part is going to be installed. Then while warming the solder on that pad use the tweezers to set the part in place. You can do adjustments while the solder is still molten. If it takes too long, let the solder cool to ensure the part is not damaged by excessive heat. Once cool the joint can be warmed up again and the alignment can be adjusted until it is perfect. Before soldering any other joints on the part use the magnifying glass to verify that the alignment is ok.
Components installed on the top of the PCB:
Install the Parallax SX48BD/TQ CPU near the center of the PCB at location U1. Pin one of the CPU should be orientated toward the upper left of the board. There is a small mark on the silkscreen, which shows the location. The alignment of this part is critical. First, tin the iron and tack the CPU in place. Do not worry about solder bridges at the moment. Once it is aligned solder one of the pins on the opposite corner. Double check the alignment with the magnifying glass. If all is well proceed to solder the rest of the pins. Since the pitch is so close on these pins just solder each side without worrying about solder bridges and let it cool before doing the next. After the chip cools go back over each side with solder wick to remove the excess solder. This will remove most of the solder and leave just enough to make a proper connection. Repeat the process if solder bridges still exist. Be sure to let the chip cool between each side so the microcontroller will not be damaged by excessive heat. The results can be fantastic if you take your time."
Everything is step by step and shouldn't be too hard to follow. If anything comes up let me know.
Best Regards,
Robert
I sent you a PM. I got my SX48 OEM module last night and had it together in a couple of hours (less a fault on my end).
All is working now on my SX48 module. I used a DEVICE SX48, OSCXT1, BOR42 instead of a DEVICE SX48, OSCXT2, BOR42 for the 20 MHz resonator that came with the kit.
As stated in your PM, it does require concentration and a steady hand but I did it. Above all you need a magnifying lense. I got a cheap one at Walmart in the hobby / crafts section that worked ok.
I used a 15w soldering iron from radio shack because of the low wattage and the only one they have with a sort of a narrower point on it. Solder wick is necessary too and the kit came with it. I also used a dot or two of super glue to align and place the chip. This helped alot.
Once this was done I carefully layed solder across every row of pins bridging them together and waited for it to cool a bit for a few seconds. Repeat on the other 3 sides. Then used the solder wick and mag lense to check remove excess solder and check for any solder bridges to be removed. It was easy once·I found a good method.
I really like it now that I can use this on my PDB or any solderless breadboard and not have to solder wires to a Protoboard just yet. That I will save for the finished project. The module is very nice for development.
Great job to Robert for an excellent product!
As you can see the first one (complete) I messed up thinking the module did not work so I carefully unsoldered the SX48 but pin 2 lifted on the board. I was able to run a short jumper wire to the OSC pin from pin 2. The problem was not on the board but in my code when I installed the 20 MHz resonator (that comes with it) but had my DEVICE line wrong (e.g. OSCXT1 and supposed to be OSCXT2). I also did not solder in the included EEPROM and socket and did not solder in the MAX232 chip and caps (as I wanted access to RA.0 to RA.3). All is working great now.
The second module has only the necessary resistors and caps (no pins, no 5v regulator and cap, etc.) as it was meant for wire soldering. This one (after my 3rd practice - worked great first time - got my technique mastered - easier than I thought).
I want to add that Robert has done an OUTSTANDING job on this. A very complete package and you couldn't ask for better docs.
Now, if I could get some free time, I'll try my hand at this SMT stuff.
Chris
Thank you both for the kind words and I am glad you are pleased with your kits! I hope that it ends up being a good introduction for using and getting familiar with the surface mount parts.
I now have some 4Mhz resonators on hand and if someone would prefer that instead of the 20Mhz resonator just let me know and I can substitute that part. Also, the offer still stands for anyone who wants the SX48 pre-installed on the board that I can do that before it goes out.
If you don't need all the extra components the blank PCB is available and makes a nice compact carrier for the SX48 for small projects. Quantity discounts will be available if you'd like several boards or kits.
Best Regards,
Robert