Among the PCBs I got back was a version of BasicUART V2 that uses FT232RL in place of MCP2200. The previous version of this design had a problem with a zone not connecting to a GND pin, which caused it to be flaky at best.
I built up one last night and it worked nicely. I will get to updating the docs and producing a few of these in the near future.
Another design in the PCB batch was a high speed DAC conversion board. This board had some issues. First the footprint for the DAC chip wasn’t correct (I needed the wide version but used the narrow version opps!). Second the opamp circuit was unstable. I was able to hack fixes for both onto the PCB to do some testing. After the fixes the output was not bad at all. It still needs improvement and that will likely require another 2 PCB iterations for what I have in mind to really test fully.
MSPism got a minor tweak to its design, which looks fine but still needs to be tested. I have some firmware written for MSPism but it isn’t what I envisioned as the final features which is why it still hasn’t been released and put on sale. If you feel strongly I should just release what I have done, sound off.
The other boards have yet to be built up for testing of any kind. One of them is for a contract and the other is a new design, for an old idea.
As noted yesterday PCBs were in the mail, today they arrived.
So this week we are giving away the new (and not yet tested) design of BasicUART. This design is based on FT232RL. I will have time to put some together this weekend I hope.
After last week’s giveaway I found out that it is against Google’s terms of service for pages to give things away directly on Google+, so while I will announce giveaways there (and thus it might be effective to join the teho Labs page) I won’t conduct the giveaways there anymore.
A random commentor will win this week’s PCB in 24 hours. Comments for first time posters are held in moderation to prevent spam.
Edit: I just built one and they do indeed work. Cristian has won.
Things are not as idle as they may seem. I know most of the posts recently have been about Free Fridays, but there are some things cooking.
Here is a brief summary of what is in the pipe.
Boards are in the mail for two designs (Seeed’s free shipping generally takes 2-3 weeks to reach me).
The first design is an updated BasicUART. These are the kinds of boards everyone needs. Basically it keeps the Ardunio friendly pinout of Sparkfun’s FTDI Basic but adds the ability to set the supply and working voltages independently. Because the internal LDO on the FT232RL isn’t really designed to supply a lot of power it uses 5V as the default rail voltage and 3.3 V for signaling (which is compatible with 5V levels anyway). If you need a small amount of 3.3V power you can set it.
The second design is an I2S (yes S) DAC board based on WM8740. This is a long delayed board for doing openHiFi.
The first batch of MSPism boards are actually assembled and finished on my workbench. However I still haven’t had time to do a polished rewrite of the firmware for that board.
Following the MSPism firmware is completing the BluePanel Andorid application and releasing the source code.
I have a couple of designs cued up to submit for a new PCB order (after I verify the new BasicUART design the new PCB order will probably go out).
I also have been working on a Java program for managing part inventories and optimizing running costs. I will be releasing more details and opening the source when it gets to a complete enough level to be useable.
I have been made aware by a user that StellarisWare’s directory structure has changed making the make files in the examples I provide incompatible with the newest version. Therefore I will try to update the guides and examples this weekend.
For those of you who can’t make the Maker Faire or just want to know what we will have here is a video of our main demo:
The Demo is based on Alpha quality MSPism boards as the slave nodes, Cygni as the master controller, the I2C sensor board we have been giving away and a few other bits and bobs. BluePanel is the name of the new Android app, which is also Alpha quality. Everything will be open sourced but it requires some cleanup work before it would be understandable to anyone else. We expect to have everything a lot more stable and tidy in October. Check back for updates!
Also we would like to note that both Cygni and BasicUART are temporarily out of stock. Normally we make a board every time we sell one so that there is always stock on hand but with Maker Faire prep there has not been time. Parts for Cygni are on hand so they should be available again soon. BasicUART has a longer lead time.
We would love to hear any thoughts on FT232RL vs MCP2000. We selected MCP2200 for revision 1 because it was less expensive and available in a less fine pitch package (less rework).
However if you build a lot of something placements also matter. FT’s offering has an internal 3.3V LDO, and doesn’t require a crystal. That reduces the external components by at least 4 placements. If you have the board manufactured that might cost 0.01/pin or it might cost 0.25/part. No matter how you look at it the external parts cost money as does placing them. This removes much of MCP22200′s cost advantage.
The question is does the community strongly prefer one or the other?