Recommended Touchscreen for nRF52810

RE: Recommended Touchscreen for nRF52810

Jørgen Holmefjord — Wed, 15 May 2019 09:22:29 GMT

We have a GFX Library Example that can be used as a starting point.

RE: Recommended Touchscreen for nRF52810

Jeremysee — Wed, 15 May 2019 07:32:00 GMT

Thank you so much for the clarification! May I ask if there is any example code for writing an image to a display?

RE: Recommended Touchscreen for nRF52810

Jørgen Holmefjord — Wed, 15 May 2019 07:29:54 GMT

Like I explained above, the 8 MHz SPI interface is capable of transferring more than double the data rate required for 240x240 pixels @ 60 Hz refresh rate. If the interface will be a bottleneck will depend on how data are written to the display, and how often you need to update the data being transmitted.

If you can reduce the refresh rate is not something I can answer. You will have to check the datasheet of your device about that. The nRF can control anything over SPI so if you display support lower refresh rates, there should be no problems.

RE: Recommended Touchscreen for nRF52810

Jeremysee — Wed, 15 May 2019 07:22:59 GMT

Will the nRF52810 limited SPI bus speed bottleneck the screen refresh rate? If yes, is it possible to reduce the refresh rate or would it be more advisable to switch to the nRF52840?

RE: Recommended Touchscreen for nRF52810

Jørgen Holmefjord — Tue, 14 May 2019 11:47:50 GMT

I'm not sure I understand your question. Do you have any specific doubts about getting it to work with nRF52810?

RE: Recommended Touchscreen for nRF52810

Jeremysee — Tue, 14 May 2019 10:14:25 GMT

What would happen if I were to try and run it on the nRF52810? I am not intending to play animations on the screen, just update data once the touchscreen is pressed.

RE: Recommended Touchscreen for nRF52810

Jørgen Holmefjord — Tue, 14 May 2019 09:25:36 GMT

240x240 @ 60 Hz corresponds to 3 456 000 bits/s. This should be possible with a dedicated SPI interface if it supports constantly streaming data, but you will have to verify this with your hardware. If you will be reading touch data through the same interface, you might be facing throughput issues.

RE: Recommended Touchscreen for nRF52810

Jeremysee — Tue, 14 May 2019 09:16:05 GMT

Should I be worried about any hardware bottlenecks for a 60Hz refresh rate on a 240x240 panel?

RE: Recommended Touchscreen for nRF52810

Jørgen Holmefjord — Tue, 14 May 2019 09:12:43 GMT

If you want to use Dual SPI mode, you will have to move to nRF52840. This has a QSPI peripheral, supporting single/dual/quad line SPI.

RE: Recommended Touchscreen for nRF52810

Jeremysee — Tue, 14 May 2019 08:44:40 GMT

To overcome the limitations of the 8Mbps SPI interface, I intend to buffer the data I send to the screen. Would that be enough or switching to a more powerful chip like the nRF52832 or nRF52840 be more advisable?

RE: Recommended Touchscreen for nRF52810

awneil — Tue, 14 May 2019 08:42:09 GMT

[quote userid="78255" url="~/f/nordic-q-a/47246/recommended-touchscreen-for-nrf52810"]using the nRF52810 chip[/quote]

Note that the nRF52810 is cut-down version of the nRF52832; it has limited Flash and RAM - so may not be a great choice if you're thinking of adding an HMI with graphics and touch ...

There is no specific touch interface.

RE: Recommended Touchscreen for nRF52810

Jeremysee — Tue, 14 May 2019 08:27:55 GMT

The screen I'm looking at uses a dual SPI interface, to use it a 60Hz refresh rate requires a 45Mbps data rate.