AWR1843AOP: mW Power and GPIO variable frequency question

Chris Willis

Part Number: AWR1843AOP
Other Parts Discussed in Thread: AWR1843

I have questions about the AWR1843AOP

It specifies a transmit output in dB but I am looking for mW. Can you provide? I am trying to meet a <100mW requirement

Also for the GPIO, I would like to use a variable frequency output which I can change depending on conditions at a frequency of 10Hz (10 times per second) and vary between 0.1Hz and 6.5kHz

Does the 1843AOP have a GPIO which could provide this?

Thank you

8 months ago

0 aozer 8 months ago

TI__Mastermind 26925 points

Hello,

The AWR1843 has an EPWM module which may be suitable for your use case. You can review section 21 of the TRM to see the details of the EPWM module.

https://www.ti.com/lit/ug/swru520e/swru520e.pdf

Regards,

Adrian

0 Chris Willis 8 months ago in reply to aozer

Intellectual 290 points

The PWM allows varying width but I want to vary the frequency. So a square wave (50% width) but vary frequency at a rate of 10Hz

0 aozer 8 months ago in reply to Chris Willis

TI__Mastermind 26925 points

Hello,

Can you provide more details on what you will use this signal for?

Also, regarding your question on output power, the transmitter output power is specified in terms of dBm (16dBm with 0dB backoff). You can directly convert this to mW using P (mW) = 1 W x 10 (P (dBm) / 10). Even at max output power you will be below the 100mW requirement.

Regards,

Adrian

0 Chris Willis 8 months ago in reply to aozer

Intellectual 290 points

Hello,

I can do my best to provide anything that will help.

We will be measuring a value and want to communicate that value on an output via a frequency which will vary from the lowest measurement at 0Hz to the highest at 6.5kHz and want to update it 10x/sec as the measurement changes.

What specifically are you wanting to know?

Thank you
Chris

0 aozer 8 months ago in reply to Chris Willis

TI__Mastermind 26925 points

Hello,

We do not have any GPIO that could accomplish this. I think you would need to look into some kind of VFO but I don't know if anything exists in that frequency range.

Regards,

Adrian

0 Chris Willis 8 months ago in reply to aozer

Intellectual 290 points

1. What are the frequency options for the PWM?

2. What rate(s) are available to change this frequency?

0 aozer 8 months ago in reply to Chris Willis

TI__Mastermind 26925 points

Hello,

I need to check with someone more familiar with the PWM module and get back to you.

Regards,

Adrian

0 Josh Wyatt 8 months ago in reply to aozer

TI__Guru* 91206 points

Chris -

Another of your colleagues posted similar question - please see it here, where the PWM usage details are covered in TRM, along with some sample code: https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1342009/awr1843aopevm-pwm-frequency-range-that-can-be-generated-using-awr1843

0 Chris Willis 8 months ago in reply to Josh Wyatt

Intellectual 290 points

Thank you Josh, but they have not answered his question either. I see that Adrian is looking into it.

0 Josh Wyatt 8 months ago in reply to Chris Willis

TI__Guru* 91206 points

Chris -

Adrian was tied up today - this is why I jumped in on this. And it was me that answered the other post and just replied to you there as well.

The way I see it, the TBCLK definitions are in table 21-15 (page 2338) and these are what is to be referenced with any of the waveform or PWM type specific formulas. Hope that helps clear it up.

0 aozer 8 months ago in reply to Josh Wyatt

TI__Mastermind 26925 points

Hello,

I checked with our team and we do not have anybody who is familiar with the PWM module. This IP was taken from previous processors and integrated into our sensor, a driver for the radar sensor was never developed for our SDK.

There is a lot of documentation on the PWM module from the processor team which you may find useful for configuring the PWM. There are also several links at the bottom for examples and API usage. All of the details are also applicable for the radar PWM module. I know this does not really answer your question, unfortunately.

Enhanced Pulse Width Modulation (PWM) and High Resolution ePWM Overview

Regards,

Adrian

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AWR1843AOP: mW Power and GPIO variable frequency question