Hello FreeCalypso community, This is a periodic update to keep everyone in the loop as to what I am doing with regard to our family of projects and what my planned upcoming steps are.
1) The first development which is expected to happen before all others is that about a month from now, in early to mid-January, we should be getting our first assembled FCDEV3B V2 boards from Technotronix, and it will be a moment of truth: will they work as expected? If the boards work as expected, I am going to make a few minor improvements to the firmware regarding sleep mode handling (hw with working sleep is a prerequisite for these minor fw changes), and I will start sending out subsidized boards to those FreeCalypso supporters who deserve them. The boards will also become available to commercial customers at the same time. 2) Assuming that the previous milestone happens without problems, my next step will be my long-planned experiment of connecting Calypso MCSI from our board to an off-the-shelf OMAP board (BeagleBoard-xM) by way of a small custom adapter which I still need to make. There are two fundamental ways in which a GSM modem can bring out the voice audio interface, analog or digital, some applications use or desire modems with analog voice interfaces (example: ZeroPhone), others use or desire modems with digital voice interfaces (examples: Neo900, other "modern" smartphone designs like Librem 5, and various GSM gateway applications), hence we need to offer both options. The GSM solution we've inherited from TI supports analog voice audio as its native way, whereas adding a digital voice interface option is a job they left for us to do. There are two entirely different ways in which one could bring out digital voice from a Calypso+Iota modem: one way is via MCSI, the other way is by tapping into VSP. MCSI is already brought out on our current FCDEV3B hardware, whereas playing with VSP would require taking the cost hit and adding the time delay of yet another board spin (quantitatively speaking, many thousands of dollars plus many months of time delay), hence I am going to make an all-out effort to get digital voice over MCSI working. But in order to test MCSI, I need to connect it to something, the McBSP on OMAP on the BeageBoard is the most practical thing I could find to which I can connect our MCSI for testing, but there is still that hurdle of having to make a little custom adapter. I also need to address some misconceptions I have found out there on the Internet regarding our work: https://www.reddit.com/r/ZeroPhone/comments/9rsukp/how_can_the_zerophone_owners_take_advantage_of/ specifically this paragraph: > In the future, it's possible they will have an "embedded" modem offering - > I did read that idea on their mailing list some time ago, though it seems > to died down in the last half a year (IIRC there was an old chipset- > compatible Benq modem that could've been a target, but it turned out to > not be compatible enough). Here is the situation with those BenQ M32 modems: taking the existing historical hw that was made by BenQ over a decade ago and trying to run FreeCalypso on it would be a non-starter, as they use a non-TI (looks like Silabs maybe) RF section behind our familiar Calypso+Iota baseband chipset. Instead my idea was different from the beginning: my idea is to produce our own newly-made modem modules in the same or similar form factor, but using our choice of chipset including memory and RF, i.e., take *our* modem as implemented on the FCDEV3B and repackage it into a form factor copied from that old BenQ modem. Why do it, what is the rationale? The answer is that in electronics, size matters, it matters a lot, but in the opposite way from how humans tend to think of it: the general dictum in the electronics industry is the smaller, the better. The imperative is to make all of our electronic components as small as possible; components of large bulky size are obstacles. Right now we have an awesome libre GSM+GPRS modem solution in the form of our FCDEV3B running fully source-enabled firmware, but the problem is its size: a whopping 90x50 mm. Meanwhile, our proprietary competitors very successfully seduce the public into accepting locked- down and backdoored proprietary solutions with their sleek small packages: for example, the popular SIM800 module is only 24x24 mm. I don't think we can ever make our FreeCalypso solution as small as 24x24 mm: SimCom were able to do it because they use much newer chips from MTK which are much more integrated (fewer discrete components), but the available documentation for these newer MTK chips is hopelessly inferior compared to what we got for our TI chipset, and in the case of MTK's reference fw for their chips, almost all of the interesting bits are binary-only, nothing like the quality of source leaks we got from TI. If anyone is thinking about taking our FreeCalypso fw and porting it to an MTK chip, what are you going to do with L1? Our L1 talks to TI's Calypso DSP, and you would need to replace it with a very different L1 that talks to MTK's very different DSP. But there is absolutely zero documentation for that DSP or the interface to it; in the case of TI chipsets we don't have any real documentation for this part either, but we got TI's L1 code in full source form, whereas MTK's counterpart is a solid binary blob. But there is one possible compromise: we *can* make a FreeCalypso modem module that isn't as small as the MTK-based SIM800, but still a lot smaller than our current 90x50 mm: if we repackage our FreeCalypso Modem Solution into a form factor copied from BenQ's old M32 module, we will measure 33.8x36.8 mm. However, before we seriously pursue this idea, two prerequisites have to happen first: 1) We need to get our FCDEV3B V2 boards working and thereby prove that my approach for satisfying the reset timing requirements of Spansion flash chips actually works. If this approach turns out to not work, we have plenty of other alternatives, the simplest being to use one of the smaller flash+RAM chips which work fine with TI's classic approach - the huge flash and RAM capacity on our FCDEV3B is only needed for development and can easily be downsized in a production modem - but it would be much more comfortable to know for sure if our FCDEV3B V2 approach works or not before jumping to any decisions. Just one more month of waiting left. 2) We need to come to a resolution on the digital voice issue before we start seriously thinking about the embedded modem module idea. Such a module would absolutely need to provide both analog and digital voice interface options - omitting either of them would be completely unacceptable. Fortunately no extra components will need to be added inside the module for either interface, it is only a matter of bringing out the right pins from the existing chips of our core modem chipset. For the analog voice interface we need to bring out EARN&EARP and MICIN&MICIP from the Iota ABB (and optionally the other less important analog signals from the same Iota ABB that were brought out on BenQ's module, if we are going to be copying their pinout with only minor changes), whereas for the digital voice interface we will need to decide between MCSI vs. VSP tap. MCSI is 4 signals, whereas my idea of tapping VSP would involve 5 signals. The decision will be pinned on the outcome of my MCSI-to-BeagleBoard experiment: if we can get MCSI to work reliably, it would make the most sense in terms of cost reduction to go into the embedded module phase with this MCSI approach, otherwise we would have to do another very slow and expensive development board spin with the VSP tap before we can come back to the embedded module idea - which is why I am pursuing the MCSI approach so vigorously. And then, after we resolve the two points above (hopefully in 2019Q1), comes the most unpleasant part of all: cost. Arsenijs wrote in that Reddit comment: > Maybe if someone throws enough money at Mychaela, we'll have something > small enough to fit inside the ZP =) As far as fitting inside the ZeroPhone, I remember you saying somewhere that it would have to fit within 24x24 mm or something similar to that - if your space constraints are that tight, then even my proposed 33.6x36.8 mm module wouldn't be good enough for you. However, for those who do like my 33.8x36.8 mm module idea, let me give you the cost figures: my estimate for the total project cost from the start to the point of having the first batch of modules produced and brought up to fully working state is about 30 kUSD. The following major cost steps will be involved: * Sending a sacrificial BenQ M32 module to a professional PCB reverser to slice it and image its inner layers - I will need to have a good idea of BenQ's layout before starting our own module layout using a similar (but not identical) chipset in the same form factor following the same floorplan or with only minor changes. * Finding and hiring a GSM cellphone RF design expert to provide some vital advice and guidance for some parts in our new RF section. Copying the RF section verbatim from BenQ won't work because we need to use TI's Rita transceiver (the one for which we have documentation and firmware driver code), and copying it verbatim from our current FCDEV3B (originally from Openmoko) won't work either because we would need a very different floorplan (one like BenQ's) to fit into that module form factor - hence we would have to bite the bullet and do our own RF layout. There is a little bit of silver lining though: because BenQ's floorplan matches TI's Leonardo, we should be able to make our new modem module quadband - in contrast, both our FCDEV3B and BenQ's original are triband. But there is no way to bypass the requirement of finding and hiring a GSM cellphone RF design expert. * After we get the key bits of advice and specific RF layout instructions from the to-be-hired GSM RF expert, we would need to hire someone to do the main bulk of the PCB layout job. Such PCB layout labor does not come cheap, and I would not feel comfortable entrusting this job to anyone other than my established PCB layout contractor with whom I have a good working relationship. * Once we have the PCB layout done for our new module, simply getting those module PCBs made and populated won't be enough - we will also need to design and build a special test fixture (a test board with a special custom-made spring socket for the modem modules to go into) for bring-up and RF calibration. Summing up all of the above is how I arrive at my rough order-of- magnitude estimate of about 30 kUSD for the whole venture. Needless to say, I am not in any position to cover such a cost myself, thus unless we get some sponsor or investor for it, this whole idea will forever remain nothing but a pipe dream. In the absence of a sponsor or investor giving us 30 kUSD to produce a modem module in this proposed 33.8x36.8 mm form factor, what can we do on our own? As the situation stands presently, I believe that the shortest way to put a FreeCalypso phone into the hands of an end user would be to make a hacked-up version of the ZeroPhone with our current 90x50 mm modem board (FCDEV3B) hacked in. As I understand it, the main "sandwich" structure of the ZP has 4x10 cm overall dimensions and is very tightly packed. Trying to squeeze our FCDEV3B somewhere in there would involve two problems: our board is a centimeter wider than the main ZP sandwich, and there is no designated place in that structure to fit an "alien" board like ours. But here is what I am thinking: if you are going to use your ZeroPhone as an actual carry-around phone, you will need to make some custom case for it, right? You are not going to try to carry a complete bare board stack of the ZP in your pocket, are you? If a custom case is required, perhaps someone who desires a Libre Phone badly enough would be willing to build a custom case that accommodates both the regular ZP sandwich and an FCDEV3B underneath? In order to increase the chance of someone stepping up to do what I just suggested above, I plan on doing the following: if the first batch of 8 FCDEV3B V2 boards which is supposed to be done in January turns out good, with all 8 boards (or least most of them) working, I am going to offer one fully subsidized board completely free of cost to the recipient (with the actual production cost of about $500 covered by me) to anyone who steps forth to couple it with a ZeroPhone, and who would be willing to commit to aggressively promoting the resulting solution in various "free my phone" communities, spreading awareness of the existence, availability and viability of this solution. Finally, it would be rightful to ask why do we need a ZeroPhone or similar component in the first place, why can't we produce a complete FreeCalypso end user phone (a libre dumbphone) entirely on our own, without putting ourselves at the mercy of other people and their capriciousness? The answer is that we very much *can* produce our own complete FreeCalypso phone handset, and that idea is still very much in the plans, but it will be a very very slow journey, which is why I believe that the ZeroPhone approach would be much faster *if* we can get someone to do it. For those who are interested in the Calypso-only handset idea (no pies or other application processors), my current estimate of the timeline looks like this: * Absolutely nothing at all will happen between now and the big day in January when I get our first FCDEV3B V2 boards; * I will probably spend January fully testing these boards and getting our firmware and documentation updated for the new state of the project; * The rest of 2019Q1 and possibly going into 2019Q2 will be spent experimenting with MCSI and getting digital voice to work, using a BeagleBoard-xM for the other end of the interface. * Once I get MCSI fully working, I will need to spend more time and effort on documentation updates and aggressive marketing, spreading awareness of our fully complete modem solution and trying to find a sponsor or investor for my 33.8x36.8 mm modem module idea. This work will probably go till the end of 2019Q2. * Unless a miracle happens and I find someone to fund my modem module idea, in 2019Q3 I will finally switch my attention to the FreeCalypso handset project. I will then start working on some preliminaries for that project, but don't expect anything fast - it will probably be another year or two from that point before we will have our first prototype of my desired handset motherboard. Needless to say, all of these timelines can be sped up by at least an order of magnitude if someone were to throw a lot of money at me, as Arsenijs put it in his Reddit comment. But in order to *really* speed up the timelines, it would need to be a *frigging lot* of money, even more than the ~30 kUSD cost of the modem module idea, hence I am not holding my breath. Hasta la Victoria, Siempre, Mychaela aka The Mother _______________________________________________ Community mailing list Community@freecalypso.org https://www.freecalypso.org/mailman/listinfo/community
