HardwareCP210xTutorial » History » Version 10
laforge, 10/26/2020 06:02 PM
link to a more maintained version of cp210x-program than the old sourceforge.net
| 1 | 8 | laforge | |
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| 2 | h2. CP210x High Baudrates Tutorial |
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| 3 | |||
| 4 | 9 | laforge | !{width:33%}cp2102.jpg! |
| 5 | 8 | laforge | This page will describe the procedure of programming high, non-standard baudrate mappings to a SiLabs CP210x serial converter using Linux, needed by the burst_ind branch. |
| 6 | 7 | laforge | |
| 7 | 8 | laforge | Small adapter PCBs to which you have to solder your own cable + plug can be bought quite cheaply on eBay and AliExpress. Ready-made adapter cables with the CP2102 can be bought from "shop.sysmocom.de":http://shop.sysmocom.de/products/cp2102-25 |
| 8 | 7 | laforge | |
| 9 | 1 | steve-m | |
| 10 | So far this tutorial has only been tested with the CP2102, but this seems to be the most common chip anyway. |
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| 13 | 8 | laforge | h3. How it works |
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| 16 | 1 | steve-m | Contrary to the FTDI converters, non-standard baudrates can't be directly requested when opening the port, but need to be stored in the EEPROM of the device, overwriting the default entries. |
| 17 | So it works like this: You open the port with a standard baudrate, the converter performs a look-up in the baudrate-table of its EEPROM and uses the non-standard mapping you programmed. |
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| 19 | 8 | laforge | If you have a [[PirelliDPL10|Pirelli DP-L10]] you don't need to continue, the CP2102 in the phone has those mappings already preprogrammed. |
| 20 | 1 | steve-m | |
| 21 | |||
| 22 | 8 | laforge | h3. Programming non-standard mappings |
| 23 | 1 | steve-m | |
| 24 | 8 | laforge | |
| 25 | 10 | laforge | First of all you need to download and unpack the lastest version of "cp210x-program":https://github.com/VCTLabs/cp210x-program, an open-source tool replacing the proprietary windows-only tool from SiLabs (see application note AN205 if you want to mess with that). |
| 26 | 8 | laforge | |
| 27 | 1 | steve-m | To make sure cp210x-program will be the only one talking to the converter, unload the kernel module: |
| 28 | |||
| 29 | 8 | laforge | <pre> |
| 30 | 1 | steve-m | sudo rmmod cp210x |
| 31 | 8 | laforge | </pre> |
| 32 | 1 | steve-m | |
| 33 | After that, perform a dry-run to see everything is okay: |
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| 34 | |||
| 35 | 8 | laforge | <pre> |
| 36 | 1 | steve-m | sudo ./cp210x-program |
| 37 | 8 | laforge | </pre> |
| 38 | 1 | steve-m | |
| 39 | The tool should output the device-string of the converter, some other information, and a baudrate table with the following default entries: |
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| 40 | 8 | laforge | <pre> |
| 41 | 1 | steve-m | [baudrate table] |
| 42 | [...] |
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| 43 | 921600 = FFE6, FFF6, 1 # 923077 Baud, 20 us |
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| 44 | [...] |
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| 45 | 460800 = FFCC, FFEC, 1 # 461538 Baud, 40 us |
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| 46 | [...] |
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| 47 | 230400 = FF98, FFD9, 1 # 230769 Baud, 78 us |
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| 48 | [...] |
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| 49 | 115200 = FF30, FFB2, 1 # 115385 Baud, 156 us |
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| 50 | [...] |
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| 51 | 8 | laforge | </pre> |
| 52 | 1 | steve-m | |
| 53 | Okay, now to the real thing: create a backup of the EEPROM: |
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| 54 | |||
| 55 | 8 | laforge | <pre> |
| 56 | 1 | steve-m | sudo ./cp210x-program -f eeprom.hex |
| 57 | 8 | laforge | </pre> |
| 58 | 1 | steve-m | |
| 59 | The next step is to program the modified, non-standard baudrates: |
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| 60 | |||
| 61 | 8 | laforge | <pre> |
| 62 | 1 | steve-m | sudo ./cp210x-program -p -F eeprom.hex -w --set-baudrate 812500:FFE2,FFF4,1 --set-baudrate 406250:FFC5,FFE9,1 --set-baudrate 203125:FF8A,FFD3,1 |
| 63 | 8 | laforge | </pre> |
| 64 | 1 | steve-m | |
| 65 | Check if the entries have been written successfully: |
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| 66 | |||
| 67 | 8 | laforge | <pre> |
| 68 | 1 | steve-m | sudo ./cp210x-program |
| 69 | 8 | laforge | </pre> |
| 70 | 1 | steve-m | |
| 71 | You should see the following entries: |
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| 72 | |||
| 73 | 8 | laforge | <pre> |
| 74 | 1 | steve-m | [baudrate table] |
| 75 | [...] |
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| 76 | 812500 = FFE2, FFF4, 1 # 800000 Baud, 24 us |
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| 77 | [...] |
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| 78 | 406250 = FFC5, FFE9, 1 # 406780 Baud, 46 us |
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| 79 | [...] |
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| 80 | 203125 = FF8A, FFD3, 1 # 203390 Baud, 90 us |
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| 81 | [...] |
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| 82 | 115200 = FF30, FFB2, 1 # 115385 Baud, 156 us |
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| 83 | [...] |
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| 84 | 8 | laforge | </pre> |
| 85 | 1 | steve-m | |
| 86 | Replug the converter and you're done. |
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| 88 | |||
| 89 | 8 | laforge | h3. Using burst_ind |
| 90 | |||
| 91 | |||
| 92 | 4 | steve-m | If you want to use the burst_ind branch with a CP210x converter, you need to add the following define in osmocon.c: |
| 93 | 8 | laforge | <pre> |
| 94 | 4 | steve-m | #define I_HAVE_A_CP210x |
| 95 | 8 | laforge | </pre> |
