Hello FreeCalypso community, Here is the current status with my effort to build our own Calypso GSM mobile station board that would serve as a better platform for our FC firmware development and debugging than any of the available phones:
* FOSS PCB approach: I haven't heard anything from Ineiev yet, and my current leaning is that redoing the layout from scratch in FOSS PCB is a step which we should tackle in a somewhat later stage of our project - see below. * Altium approach: the off-list person who took a stab at loading Openmoko's PADS PCB file into Altium (the software he happens to be using) and editing it there didn't progress very far. He did a gerber export from what he had and sent it to me so I could see it (not having Altium myself), and I saw that the translation from PADS to Altium was quite lossy: the copper pours were lost, the footprints ended up on the wrong layers etc. I am not putting much faith into this Altium approach any more. The approach which seems most promising at this point is for me to do the layout of the first version of our development board in PADS based on the PADS file for GTA02-MB-A6 which we recovered from Openmoko. It began with me finding a cracked copy of PADS on the well-known pirate site: https://thepiratebay.la/torrent/8569591/PADS.9.4.1-EFA Then there was the problem that it's Windows-only software, and I am absolutely not a Windows user. I solved that one by digging up a sacrificial laptop and installing WinXP on it. (Why XP and not something newer? Well, I figured that Windows only gets more evil as it gets newer, hence older versions ought to be a little less evil - and security isn't an issue as that box will never be connected to the Internet or any other networks, totally isolated and air-gapped, data in and out only via USB flash drive sticks.) So I transferred the pirate copy of PADS to that isolated WinXP laptop via a USB stick, and it installed fine. The pirate license key generator worked too - PADS swallowed the license file it generated and is now able to load large design files (like Openmoko's) without disabling save and export operations like it does in "demo" mode when it has no license key. I know that using PADS can be considered cheating: the morally right approach would be to do all of our PCBs solely in FOSS PCB. But right now we are in a peculiar situation: if we deem the triband RFFE configuration to be sufficient for our first development board (i.e., if we don't need quadband capability right away), we have the opportunity to reuse Openmoko's known-working PCB design verbatim without having to redo it anew - but such verbatim reuse practically requires that our FCDEV3B board (FreeCalypso development board, triband) be done in PADS; doing it in FOSS PCB would practically imply having to redo the layout from scratch. While I still see it as a goal that we should eventually produce a quadband Calypso modem whose PCB design is done purely in FOSS, my current plan of attack is to split the task into two stages: 1: Produce a triband version (FCDEV3B) through verbatim reuse of Openmoko's 8-layer PCB design with blind and buried vias (L1-L2, L2-L3, L3-L6, L6-L7, L7-L8). Do it in PADS: start with the GTA02-MB-A6 PCB file from Om, delete all components outside of the modem section, load the new netlist for FCDEV3B, place and route the newly added peripheral components (connectors etc) and voila, we'll have a board design ready to go to PCB fab. We'll be able to use this board for all FC fw development and debugging tasks for which the band support doesn't matter: find and fix the current DSP patch loading bug that prevents voice calls from working, play with the pdt_2092 (UI included) configuration of TCS211, explore the melody generation capabilities of the Calypso DSP, play with CSD and GPRS, etc. 2: After FCDEV3B has been built and fully proven working (calibration followed by full TCS211 functionality), we can tackle the challenge of making a quadband version as a separate subproject. Openmoko's specific PCB layout of the modem section works only with their specific type of triband antenna switch and its particular pinout; replacing this triband RFFE with Epcos M034F (the magic component used by TI in their Leonardo and E-Sample designs that made them quadband) will require redoing the whole layout in a different way, using a different component placement arrangement that is more like Leonardo and E-Sample. And if we have to redo the layout anew in order to make our modem quadband, that would be the perfect time to switch from PADS to FOSS PCB. When the time comes to do our quadband design as stage 2 per the above, I hope Ineiev will be available to do the PCB layout for us, but as for stage 1 (doing FCDEV3B in PADS), I would like to try doing it myself. Yes, you read it right: I, Mychaela Falconia, would like to try my own hand at a PCB layout job. I reason that I may be able to do this one on my own because the vast majority of the layout, including the tricky GHz RF section and the mass of digital signals between Calypso, Iota and the memory chip, is to be reused verbatim from Openmoko, and the only new routing to be done consists of just a few signals, none of which are particularly critical. Oh, and the pirate copy of PADS at the torrent link above does come with quite thorough documentation on how to use it. :) And for anyone who thinks that piracy is bad or immoral, I disagree: it is immoral for Mentor Graphics (the makers of PADS) and other such companies to make money by selling super-expensive licenses to involuntary customers who are kept hostage by proprietary file formats and the practical infeasibility of moving a complex PCB design from one EDA package to another without losing half of it in translation, so by using a pirate copy we avoid giving any of our money to those vultures. Note about E-sample: that was TI's development board for the Calypso+ chipset. We happen to have a copy of TI's layout for this board: ftp://ftp.freecalypso.org/pub/GSM/PCB/Esam-406.zip And guess what - it is also done in PADS! With a working installation of PADS that can read the Esam-406.pcb file we got, I could easily generate gerbers for that board, we could send them to a fab and get a physical E-sample board back. But unfortunately it won't do us any good: we only have firmware for the classic Calypso and for LoCosto, but not for Calypso+. :-( So we still need to build our own board with the chipset we need, based on Openmoko. The specific chipset we are working with is Calypso/Iota/Rita. TI's D-Sample board was Calypso/Iota/Clara, while E-Sample is Calypso+/Syren/Rita - hence the chipset we are working with is later than D-Sample but earlier than E-Sample. Thus when we build our own development board for the chipset we need, we can call it DD-Sample: more than a D, but not quite an E. :-))))) Happy hacking, SF _______________________________________________ Community mailing list [email protected] https://www.freecalypso.org/mailman/listinfo/community
