Timeline for UART devices: Baud rates different by a factor
Current License: CC BY-SA 3.0
15 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 24, 2017 at 8:02 | vote | accept | Potaito | ||
| Nov 21, 2017 at 17:56 | answer | added | bigjosh | timeline score: 2 | |
| Nov 21, 2017 at 17:38 | comment | added | Mitu Raj | Writing your own software UART is the only option I guess... | |
| Nov 21, 2017 at 14:12 | comment | added | Potaito | It is a proprietary product I am using. So yeah, it does not allow arbitrary baud rates, but a few custom ones that are hard-coded (again, proprietary product. With the source code I could change it). That's why I am restricted to these rates or the very standard ones. Also I don't know what exact microcontroller/oscillators are on that board. | |
| Nov 21, 2017 at 13:29 | comment | added | Tom Carpenter | I'd be highly surprised if it can do a custom rate of 3M but couldn't do custom rates of 150k or 300k or 600k. Your proposed idea of running 5 times faster forgets that there are start and stop bits in UART, so if your data doesn't happen to have a 1 where the stop bit needs to be and 0 where the start bit should be it won't work. Plus you can't guarantee that the MCU won't leave gaps between each packet. | |
| Nov 21, 2017 at 13:25 | comment | added | Tut | How about stating what board/microcontroller you are talking about. If possible, also state the frequency(frequencies) of it's oscillator(s). | |
| Nov 21, 2017 at 13:21 | history | edited | Potaito | CC BY-SA 3.0 |
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| Nov 21, 2017 at 13:21 | comment | added | Arsenal | Hacking a hardware UART to do this will probably fail. If you implement a software UART on the corresponding pin, you can get those baudrates. But I've not encountered a micro with such restrictions on the UART - care to share which one it is? | |
| Nov 21, 2017 at 13:19 | comment | added | Potaito | See my updated question | |
| Nov 21, 2017 at 13:18 | history | edited | Potaito | CC BY-SA 3.0 |
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| Nov 21, 2017 at 8:34 | comment | added | pipe | You might be missing something. This is a pretty odd situation, and I think you will get far better solutions if you don't hide what you're trying to configure, and give us the baud rates or equations to calculate them. | |
| Nov 21, 2017 at 8:19 | comment | added | Tom Carpenter | What devices are you using. Some USB to serial devices don't support custom baud rates and default to the nearest allowed. | |
| Nov 21, 2017 at 8:13 | comment | added | Jubatian | How much they differ? Two UART devices may be able communicate with each other if their rate is within about 3%. Otherwise you are out of luck with the UART device, but you may implement it in software by bit-banging. But nowadays it shouldn't be necessary (UARTs are usually flexible enough in their capability to set up arbitrary data rates). Could you tell what are the devices in question? (Someone might have some knowledge of them to help) | |
| Nov 21, 2017 at 8:02 | review | First posts | |||
| Nov 21, 2017 at 10:34 | |||||
| Nov 21, 2017 at 7:59 | history | asked | Potaito | CC BY-SA 3.0 |