UART receiver not using the UART component

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Anonymous
Not applicable

Hi

   

Due to an unforeseen requirement (an LVTTL RS232 sensor device output needs to be connected to an RS232 level convertor input), the RS232 RX data is received inverted at the PSoC4.

   

I see that the standard UART component has an IrDA mode which allows an inverted RX but the signaling is of course different, and the inversion setting is not available in non-IrDA modes.

   

So, does anyone know of a software RS232 RX example for a baud rate of 9600?

   

Thanks for any pointers.

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1 Solution
HeLi_263931
Level 8
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The CYBLE-014008-00 data sheet says it got 4 UDBs: www.cypress.com/file/190771/download . I just created a new project with this module, and could place an UDB UART.

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12 Replies
Bob_Marlowe
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When using a CY8C42xx you may use the UDB-version of the UART, there you can put a NOT gate to the Rx pin.

   

 

   

Bob

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Anonymous
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Thanks.

   

I think there is so much I have to learn.

   

I'm using a CYBLE-014008-00. I can't see a UDB version in the component catalog. 

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Bob_Marlowe
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Too bad, but none of the CYBLE modules have got UDBs.

   

 

   

Bob

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Anonymous
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That's a bit of a bu**er!

   

So, either I stick a proper RS232 level translator onto this sensor, or I implement a software UART (Rx only needed).

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Bob_Marlowe
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 I can assure you that a software Rx is quite more difficult to realize than a Tx. Did you consider pruning with the generated sources to see if it is possible to invert the signal at the pin?

   

EDIT: Just checked: seems not possible. Can you use a chip with opamps and use one of them as an inverter?

   

Bob

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HeLi_263931
Level 8
Level 8
100 solutions authored 50 solutions authored 25 solutions authored

The CYBLE-014008-00 data sheet says it got 4 UDBs: www.cypress.com/file/190771/download . I just created a new project with this module, and could place an UDB UART.

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Anonymous
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Thanks hli.

   

What is the process of adding the UDB UART as I can't see it in the component catalog?

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Are you sure your project has the BLE module selected you stated above? Because I just used the latest Creator version (maybe you should update), created anew project with this component and the UART was available for selection (you can search for it in the component selector).

   

If not - can you post your project?

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Anonymous
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I updated yesterday and am now running PSoC Creator 4.0 (4.0.0.432).

   

I don't have a project to share as it is a new project. File > New > Project. Select target module as CYBLE-014008-00, Click next.

   

Choose empty schematic, click next. Select workspace and project name. Click finish.

   

I then get an empty schematic page and move the mouse to the component catalog (maybe that's out of date). If I search for UDB then all I can see is a UDB Clock Enable and a UDB Timer. If I search for UART I get a Software Transmit UART, UART (SCB mode), UART (v2.50), USBUART, and a Base UART (verilog).

   

Could you post a project you've created with just the UDB UART?

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Anonymous
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Hmm. Would I be correct in saying that the component listed as UART[v2.50] is actually the UDB one?

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Bob_Marlowe
Level 10
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Yes, that is quite right. In the datasheet under "Resources" you will see the used UDBs.

   

 

   

Bob

Anonymous
Not applicable

Thanks.

   

I do indeed see used UDB resources with that UART.

   

Problem solved.

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