The Industrial Raspberry Pi Forum

Hi,

I have multiple questions since I am considering migrating an existing project from a Pi Compute to the RevPi's.

1. I have a python app that runs on a touchscreen and interacts with the GPIOs through python module RPi-GPIO. With the RevPi DI and DO modules, can I still use my RPi-GPIO module that references the BCM pin numbers to interact with the GPIO? The RPi-GPIO module already provides rising/falling monitoring of GPIO inputs and it is easy to write to outputs. Will my transition be seamless or is there some other layer to interacting with the GPIOs?

2. Is there any protection from powering off the RevPi while the eMMC is being written? I know in some cases the eMMC can become corrupted if power is abruptly turned off.

3. As for the OS, is there an image that has no desktop? I have been using the Raspbian Lite and installing the XWindows packages myself to run my python touchscreen app.

Thanks in advance!!

1. I have a python app that runs on a touchscreen and interacts with the GPIOs through python module RPi-GPIO. With the RevPi DI and DO modules, can I still use my RPi-GPIO module that references the BCM pin numbers to interact with the GPIO? The RPi-GPIO module already provides rising/falling monitoring of GPIO inputs and it is easy to write to outputs. Will my transition be seamless or is there some other layer to interacting with the GPIOs?

The GPIOs of the compute module within Revolution Pi are used internally (e.g. for communication tih extension modules). There are workarounds to access certain GPIOs (e.G. SPI, UART) on the RevPi Connect via the ConBridge.
But it is not meant to be done this way. The supported and standard way is: Customers use touchscreens via HDMI and USB. E.g. Waveshare (as Component) or complete industrial touchschreens like https://revolution.kunbus.de/shop/en/accessories.

2. Is there any protection from powering off the RevPi while the eMMC is being written? I know in some cases the eMMC can become corrupted if power is abruptly turned off.

The official answer would be: Use a USP. RevPi Connect for instance has a digital input where you can attach a USP's signal. This allows you to perform a graceful shutdown when USP battery runs low.
https://revolution.kunbus.com/tutorials ... rect=en_US
That is the official 100% bullet-proof answer. BUT: I have been using RevPi Cores as a customer for years in countless projects. I have never everperienced or heared of any problems with eEMMC. Hard power off was always our standard routine. Also our support team has not experienced any case in that direction yet.

3. As for the OS, is there an image that has no desktop? I have been using the Raspbian Lite and installing the XWindows packages myself to run my python touchscreen app.

No there is not. As you might know you can deactivate the desktop in the pi settings or via the console. https://www.raspberrypi.org/documentati ... -config.md

Hope this helps.

nanok66 wrote: ↑11 Jun 2021, 00:42 3. As for the OS, is there an image that has no desktop? I have been using the Raspbian Lite and installing the XWindows packages myself to run my python touchscreen app.

We currently don't provide an Lite image. But you can create one with our imagebakery: https://github.com/RevolutionPi/imagebakery

Best regards,
Philipp