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Forum Index : Microcontroller and PC projects : CMM2: Next steps?
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| robert.rozee Guru  Joined: 31/12/2012 Location: New ZealandPosts: 2428 |
"The closed hardware, need for NDA etc, make this problematic": not at all. linux on the RPi uses a 'binary blob' to interface with the proprietary stuff, with the linux-facing side completely open for anyone to use, and documented via the linux source code itself. all you need to do is talk to the blob, which is (as far as i am aware) free to distribute however you so choose. is there any functionality, that micromite basic needs to use, within the RPi hardware that is not accessible via the blob? how would the performance of RPi + blob + MMbasic compare with the performance of H7 + MMbasic? bear in mind the massive memory and CPU resources available on even the lowest-end RPi. cheers, rob :-) |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 4033 |
So far as I can see, you can't do it that way unless you GPL the result. Also, you would need to have the copyright owner's explicit permission to use & distribute the blob. (The default with copyright is no permission at all.) There has been talk of NDA(s) so I suspect it is an issue. It may be an OK NDA and the owners may well grant permission. Hopefully so. On the non-copyright end of things (i.e. software) I've not looked due to the copyright problems which I wish not to face. Benchmarks of picromite/CMM2 probably give some indication of (raw) performance. John Edited 2020-06-28 01:57 by JohnS |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2428 |
So far as I can see, you can't do it that way unless you GPL the result: why? the blob isn't GPL, and even if it was, the only requirement would be to release any changes you made to it - and no one is going to be making changes to it! we are merely picking up a chunk of binary code (the blob), from a freely distributed source, and depositing it onto an SD card. next, we're picking up another chunk of binary code (a pre-compiled version of MMbasic from Geoff and/or Peter), and dropping it onto the same SD card. job done. there is even open-source code out there, in the form of an application called "rpi-imager" https://github.com/raspberrypi/rpi-imager, that is capable of grabbing a copy the RPi image from the RPi foundation's servers. so we don't even need to distribute the blob ourselves, we can just use an existing program to uplift it - or create a RPi linux distro on an SD card and then delete the linux part from it (ie, leaving just the blob). i'm afraid that i see the whole closed-source/NDA argument put up by many as simply a spurious excuse. there is no incompatibility between the applicable licences, and the blob is out there and free to be used (via the linux-facing side) by anyone who wishes. the blob does the job, even when used just as broadcom intended. cheers, rob :-) |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 10194 |
The next steps for the CMM2 do not include anything to do with the Raspberry Pi |
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| damos Regular Member  Joined: 15/04/2016 Location: AustraliaPosts: 74 |
Thanks for that info Jim. Where in the manual does it describe how to create arbitrary waveforms? I can't see a specific command to play from an array. I was particularly wanting to pass an array to the play sound function with an array of data that it will repetitively play until told to stop, but would be happy with playing from a large array. The timer routine is buggy. I works for times less than 1ms, but it is inaccurate above 1/650s. dim f - 500 do play sound 11,L,S,f pause 1000/f play stop pause 1 loop This plays a single period and then does 1 ms pause to it is easy to see what is going on. If you look at this on an oscilloscope, it works perfectly for values of f above 650. Below 650Hz it chops the waveform as if it is rounding the pause down to the nearest ms. |
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TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 6266 |
Look up the DAC command VK7JH MMedit |
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Turbo46 Guru Joined: 24/12/2017 Location: AustraliaPosts: 1638 |
Serial Mouse: I would like to have one but not at the permanent cost of a serial COM port. Perhaps another OPTION? OPTION COMnbr MOUSE ON|OFF or OPTION MOUSE COMnbr ON|OFF the COM port parameters could be set in the usual way Return the pointer location by maybe: MM.INFO(MHPOS) MM.INFO(MVPOS) Bill PS I am aware of TassyJim's efforts using a PS2 mouse and Arduino and have used the Silicon Chip USB to serial mouse adaptor myself. Raros started it years ago with a real serial mouse. Now I see vegepete is using one also. PPS Sorry for the repeat post but the first one was not responded to. Keep safe. Live long and prosper. |
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vegipete Guru Joined: 29/01/2013 Location: CanadaPosts: 1127 |
I must say, a mouse is a joy to use, especially now that we can read the state of the [SHIFT] and [CTRL] keys. The trouble is, ps/2 mice are easy (enough) to interface with but are becoming rare, and USB mice need either a chunk of USB stack code or more hardware. For example, look at this USB host board. Visit Vegipete's *Mite Library for cool programs. |
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| Turbo46 Guru Joined: 24/12/2017 Location: AustraliaPosts: 1638 |
I agree, this is the one I use. It uses a close relative of the Micromite (a 270) and can be programmed with the Microbridge. Bill Keep safe. Live long and prosper. |
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| vegipete Guru Joined: 29/01/2013 Location: CanadaPosts: 1127 |
An entire PIC32MX270 to serve as a USB host controller? Yikes. I'm watching Bitluni's USB host controller project for ideas. An interface with 2 USB ports, mouse and joystick/game controller, would be just the ticket. Perhaps linked by I2C. Visit Vegipete's *Mite Library for cool programs. |
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thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4301 |
Good morning, Can anything be done about the fact that the first parameter of RUN needs to be string literal and not a string variable ? With this restriction in place if program A want to pass control to program B then program B has to be in a fixed location ... and you wouldn't even make SEARCH PATH a fixed location  In an earlier thread you pooh-poohed Jim's clever workaround of writing a temporary .BAS file containing the hardcoded RUN describing it thus: "This is a CATASTROPHICally bad idea and causes the flash to be re-written twice." So what is our alternative? Incidentally how many writes is the CMM2 flash guaranteed for? My understanding is each time we RUN then unless the program currently stored in the flash is identical to the program we are RUNNing then the flash is overwritten. That means I could easily be rewriting the flash 50-100 times in an evening's development. If the flash is guaranteed for <ignoramus pulls figure from google>10,000 writes</ignoramus> then do I need to be lining up spare Waveshare boards like printer-cartridges? Regards, Tom Edited 2020-06-28 19:54 by thwill MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 10194 |
No: the choice is between three options string literal and MM.CMDLINE$ or variable and no MM.CMDLINE$ or no RUN without a filename and MM.CMDLINE$ There is no possible way of parsing and getting all three |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4301 |
I know your reserved about the details, but I'm going to ask "Why?" 1. Tokenize the statement. 2. All tokens after RUN and up to the first comma (unless that comment is enclosed in quotes) are evaluated as a string expression used to determine the file to RUN. 3. Everything after that first comma token is passed verbatim to MM.CMDLINE$ Edit 1: OK, not quite so trivial, but IMO still doable as you need to handle someone deciding that they want to use a string expression involving a multi-dimensional array or a function call with more than 1 parameter as these add additional commas ... Edit 2: If it helps then *I believe* I can write this code in BASIC since I've already built a tokenizer. If you want it in C then that will take me a bit longer. Unless that is there are limitations outide of parsing that you've not expounded upon. Regards, Tom Edited 2020-06-28 20:46 by thwill MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 10194 |
Because on this one I'm simply not going to spend more time and effort for a limited use case |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4301 |
Fair enough. Could you please comment on my question about flash rewriting ? - Have I got the essential details correct ? - Do we potentially have the Tesla problem ? - I recognise I'm not a hardware guy and might be talking complete sh*t. One of the reasons I'm concerned is that my proposal for a utility that manages the contents of SEARCH PATH and creates "links" between files in there and the actual implementations means an additional flash write for an execution and I don't want to be responsible for people's Waveshares wearing out. Regards, Tom Edited 2020-06-28 21:09 by thwill MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 10194 |
Minimum guaranteed flash endurance is 10,000 writes. I don't suppose anyone will get near the number I've done in development and I haven't hit an issue |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4301 |
Thank you. 10,000 / 50 = 200 days ... hmm, I'm still a little concerned. I think maybe I'll buy a spare ;-) Tom MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 4033 |
I replied to your post about using the Linux source code to figure out how to use the blob. Doing that opens you to GPL. To avoid it you'd have to do it the "clean room" way used e.g. to create a non-copyright-infringing IBM PC BIOS. If you're confident, though, just do it :) It may well be that in practice no-one will care, especially as the number of potentially infringing copies would be very low. However, the RPi strikes me as a poor choice due to its very limited I/O. Also, its rather high power usage. John |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4301 |
Not that I'm terribly familiar with it, but what do you hope to gain that you wouldn't get running RISC OS on the Pi? That boots almost instantaneously and has a powerful BASIC with O/S level integration a couple of key presses away. It even comes with a community of ardent devotees. Regards, Tom MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2428 |
i'd have to agree on that - there is limited I/O, and the newer ones are starting to get up there with their power consumption. the RPi 4 is no better than a low-end laptop in many regards. plus, it would not be an easy programming task, certainly not something i could be bothered with myself! the pluses of the RPi that i've always seen for ANY project are: 1. it is CHEAP, especially for a RPi zero or A+; 2. it has HDMI socket soldered to the PCB, which is increasingly becoming a necessity; 3. 256mb is heaps of onboard RAM for a basic or a BASIC computer; 4. the 'early' ones could be configured for relatively low power consumption. having said that, the CMM2 is a wonderful bit of kit, a major draw being that people can solder it together themselves. there are far too few things these days that you can build yourself! cheers, rob :-) |
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