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UART receiver not using the UART component | Cypress Semiconductor

UART receiver not using the UART component

Summary: 12 Replies, Latest post by Graeme Parker on 29 Nov 2016 02:37 AM PST
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Graeme Parker's picture
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43 posts

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.

user_1377889's picture
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9606 posts

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

Graeme Parker's picture
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43 posts

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. 

user_1377889's picture
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9606 posts

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

 

Bob

Graeme Parker's picture
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43 posts

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).

user_1377889's picture
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9606 posts

 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

hli
user_78878863's picture
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2582 posts

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.

Graeme Parker's picture
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43 posts

Thanks hli.

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

hli
user_78878863's picture
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2582 posts

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?

Graeme Parker's picture
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43 posts

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?

 

 

Graeme Parker's picture
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43 posts

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

 

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