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RadioInterface Update

A project log for VUHF Radio

A dual band VHF/UHF module based around two AX5043 radios. Built to work with HAM Radio communications using AFSK and G3RUH modulations.

NotBlackMagicNotBlackMagic 07/18/2021 at 19:291 Comment

The RadioInterface Module software has been updated to now be able to switch between both the two VUHFRadio channels, VHF and UHF, seamlessly. Also, some performance tweaks were done to the SPI driver that communicates with the LCD (ILI9341): removing the CS toggle for every byte transfer and keeping it LOW all the time, the transfer speed was more then doubled.

Also, a new special feature was added, a Waterfall window. It takes the RSSI and RF tracking variables and creates a Waterfall of it, with a "traditional' color gradient and vertical scrolling! The refresh rate is currently limited to 5Hz as it takes around 150ms to refresh the Waterfall window. The vertical scrolling consumes around 99% of this time as every line has to be read from the LCDs GRAM and written back one line/row further down. The hardware accelerated scrolling included in the ILI9341 LCD driver can't be used as it does not modify the GRAM content and therefore when the vertical scrolling mode is exited, to draw on other parts of the screen, the scrolling is lost.

There is still has some margin for improvements, specially in the refresh speed, but it is working pretty well and is very useful already. Bellow is a short clip showing the Waterfall Window working, with a frequency sweep at the VUHFRadio module input:

The updated code of the RadioInterface module is published on GitHub and a new section has been added to the website with some more information.

Discussions

Burrmaster97 wrote 07/24/2021 at 17:19 point

A waterfall is a great thing, considering the speed of the PLL chip!

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