That looks great, Tari! Where should we proceed from here? Would you like geekboy or myself to think about a version that would fit onto the USB and I/O pins of the TI-84+, or should we go ahead and get this fabbed (and stencils made) so we can start testing and writing firmware before we worry about form factors?

It'll probably take at least a few revisions to get something that works reliably, so I'd rather just run with this port layout for now. Before anything can be fabbed, we need to finalize a BOM.

Excellent point; I sort of figured that was the answer to my question as I was writing it. We at least know all the major ICs from our discussions; how about all the passives?

Yeah a BOM please. *is excited to mess with the solderpaste*

Kerm did you ever order yours?

Tari. You need to adjust the pcb design to expose the xtal pins for Dco calibration. I'v. Narrowed that down to a big reason why my old code was failing

No need for a change. The TCK pin (which is broken out to the programming header) can be reconfigured to output SMCLK, which can in turn be pegged to MCLK.

IIRC this device has factory calibration values for 1, 8, 12 and 16 MHz MCLK via the DCO, so I don't think manual calibration is even necessary unless you're planning to use some weird DCO frequency.

Alternately, throw a 32 kHz crystal on LFXT1 and implement a PLL in software (with two timers) for self-calibration.

Self calibration was the idea because reading through stuff. People say that the Dco pre calibrated data can vary a lot. It would really just be for a sanity measure.

I've not done any empirical testing of factory-calibrated DCO values, but I'd assume they're pretty spot-on. Certainly the incidental measurements I've done have been correct to at least a few decimal places.

'course, adding a crystal doesn't affect the system much. I'll have a look at it next time I pull out the designs.

please and thank you ^^ its also because wiping the precalibrated data is really easy depending on the debugger you are using...case and point both of my msp430s are wiped :/

Sorry, I have not read all of this thread, but could you power this off of the usb port?

My idea for the networking is to have an index for the packet, lets say 8 bit, so if the interface has seen that number within ten or so, or it's age is to high, the packet will not be repeated, otherwise it will be if it is not a broadcast or for the current device. How does this sound?

Yes, I have been thinking about this since I found out about calcnet a few years ago, it helps to have a basic understanding of how the current networks are working. ☺

Is this project like, totally dead?

We want it finished but the time has not be available to work on it for any of the parties involved. So yes its been backburnered but not not dead dead

*KermMartian pulls out the designs and dumps them over Tari's head as a reminder.

*CalebHansberry does too

Thanks for reminding us about this, Caleb. It hasn't been forgotten; it's just on the back burner until the three of us manage to find the time to do the project justice.

In case you missed it, Hackaday posted an article about another point-to-point calculator wireless link. Although it's nothing new (cf. the old RF link that ticalc.org posted as well as Sami's IR link), it's cool that they got it working, and we should consider trying to recruit the creators to help with this project.

Bump bump bumpity bump. Just a reminder to all parties involved that this is definitely a project we should pick up in the near future. At the very least, we should all ensure that we have the proper tools (like a decent reflow oven) for working with the necessary SMT parts.

Just out of stupid curiosity, how well would this work with the stuff Brandon has been working on for the last 2 weeksish?

With the currently decided hardware it will not. the hardware we have picked is a radio chip that talks on a very different frequency then the stuff Brandon has been working on. So it would be a completely different item. It could in theory replicate the features of what Brandon has been hacking tho.

What is the current ic for the wireless coms?