Need information regarding nrf52833 usage

[AIRAM]

Hi,

I have been conducting research for a product configuration that necessitates HDMI video output, alongside the integration of HX711 and st7920 components. In consideration of microcontroller options, I am contemplating the utilization of the nrf52833. My understanding is that both HX711 and st7920 utilize the SPI protocol, . Fortunately, the nrf52833 supports both of these communication protocols. Additionally, the desired BLE functionality is also available in the nrf52833.for hdmi video i'll be using a HDMI Transmitter.

I seek confirmation regarding the appropriateness of this microcontroller choice for seamless integration with the mentioned components, or if there are alternative microcontrollers that better support the functionalities required for this configuration.

[Jørgen Holmefjord]

Hi,

By default, it looks like HX711 does not support normal SPI protocol, but it can be read using bit-banging (see example in driver implementation for Zephyr). ST7910 seems to support a serial interface mode, which should be interfaceable using SPI.

I'm not sure what interface your HDMI transmitter chip supports, or what kind of throughput you would require for your application, but note that BLE is not ideal for video streaming.

The nRF52833 might work if you do not have have heavy CPU activity, but given that you need to support multiple interfaces, data sampling, and BLE, you might want to consider one of the newer generations with dual-core CPU support (nRF5340 available now, nRF54H20 coming soon).

Best regards,
Jørgen

[AIRAM]

Hi Jorgen Holmefjord,

Thanks for the information, at HDMI output i just need monochrome text to display, and i am thinking to use a HDMI transmitter IC TDA19988 with it for HDMI output.
Is this okay , can nRF52340 r nRF52833 handle this easily?

[Jørgen Holmefjord]

I did not study the datasheet of the HDMI transmitter in details, but it looks like it takes video as 3*8-bit clocked parallel input. The nRF52833 does not support parallel output in HW, and I do not think it would be feasible to bit-bang high resolution/frequency video. Unless the HDMI transmitter can be interfaced/controlled in some other way, I'm not sure if this is the best fit for your application.

[AIRAM]

Thank jorgen,

Is there any possibility that nRF52833/840 can do a VGA video out , by using some additional components. And then from VGA to HDMI conversion.

[Jørgen Holmefjord]

I'm not aware of anything. You could check online if you find anything that supports SPI, but I think this will be too slow for video output.