The All-band HF Amateur Radio Transceiver: Just waiting to be modified
Lowell has tested current draw on a 2.4″ and a 3.2″ Nextion display following questions from constructors over the likelihood of cooking the existing 5V regulator. With a supply voltage of 5.04 VDC, the 2.4″ display drew 125 ma. and the 3.2″ display drew 110 ma. Both displays were at full brightness. While the figures are slightly above those listed on manufacturer’s website, this suggests the 5V regulator should be fine. If in doubt, add a heatsink!
Ian Lee KD8CEC has released Beta firmware for the µBITx that supports Nextion colour touch screens . He has also released matching files for installing firmware in the Nextion displays for 2.4″ and 2.8″ screen sizes. No programming is required to use these displays.
The photo above shows the touch panel display. Pressing on the screen will perform functions like changing band (up/down), changing frequency, adjusting the Attentuator (ATT), IF Shift and RIT, and going into Split mode.
See Ian’s webpage for details about downloading the various firmware options along with detailed instructions.
If this display looks like it is from a commercial rig, then you are wrong! It is the Nextion display mounted on a µBITx!
Ian KD8CEC will shortly release his newest enhancement to CEC firmware. His latest modification to the CEC firmware supports Nextion screens. This was foreshadowed recently on the BITX20 list.
THIS WILL BE THE MOST AMAZING ENHANCEMENT YET FOR UBITX!
If you want further proof, check out Ian’s recently prepared youtube video of the Nextion screen in operation. His release is imminent.
Get your order in for a Nextion display immediately, as they are likely to sell out when 6000 µBITx owners twig that they really do NEED a Nextion display. [Note that ubitx.net has no relationship with ITEAD – who make the Nextion!]
There are some very good reasons why the Nextion display is the way to go:
Nextion display units cost more than other displays for a reason. The independent processor removes most of the burden for screen manipulation from the main processor, and it is much quicker and easier to develop the user interface and to customise it for different sized screens and to add/subtract features. Nextion displays also include a microSD card reader. They run on +5v DC and include a serial port. Note that the Enhanced Model contains a battery mount for the RTC, but does not include the battery (CR1220) itself. This is not required until you want to use the RTC.
It will be VERY EASY to add a Nextion display to your µBITx. Watch the video!
No hardware modifications are required to your µBITx, but you will of course need enough front panel space to install your colour touch display of choice. You may even need a bigger case if you want to install the 7″ Nextion display!
You will also need to download two new files:
The downloaded firmware for the Nextion needs to match with your screen size. There are two variants for each screen size: a BASIC or ENHANCED version of the Nextion display unit (see the discussion on which version to buy below).
This firmware needs to be saved to a microSD card (a 2GB or larger card is required). Insert the card in the Nextion display and in powering up the Nextion display will automatically load the firmware from the microSD card into the Nextion flash storage. Remove the microSD card when the upload is complete.
Four wires connect the Nextion display to the Raduino. Two lines are for power, and the other two are serial RX and TX that connect to standard IO ports on the µBITx that were used for the 16×2 standard display.
Reboot your µBITx and your Nextion display should be working!
There are two versions of the Nextion Display – one developed for the Chinese market and an English language version that supports the Nextion Windows development environment. Make sure you don’t get the cheaper, but incompatible Chinese version. Look out for “English Version” in the marketing blurb. This won’t be an issue if you buy from the developer (ITEAD).
I understand a downloadable hex file will be available that works the same as the English version, for those of us who purchased the wrong model in error! Thanks to Ian, who did it blind (also not being able to read Chinese)!
Any size will work with the CEC firmware on the Raduino end. However, Nextion firmware is specific to either the BASIC or ENHANCED version of the screen and to the resolution of the screen. That said, any version can be modified to work with any other screen size with just a little bit of work on the part of the user. You can also fully customise your screen to meet your own requirements. Change the colours, or change the entire look and feel. No coding is required to do this, just cut and paste the code from the supplied CEC version for each tool.
Purchase the ENHANCED model of the Nextion (for a few more dollars) if you think you will use the GPIO or RTC features in future. The RTC could be useful for digital modes that require precise timing, or for satellite work, etc. Additional GPIO lines could solve one of the problems with the Raduino: a lack of spare digital ports to support customised add-ons. For example, if you want to add 160m and switch in an additional LPF, or if you are worried about potential spurs, you will be able to pull in bandpass filters for the high bands. In these instances you may want to spend a little more to get the ENHANCED version.
If you don’t want to wait until firmware is available for your screen size, then purchase a 2.4″ or 2.8″ BASIC or ENHANCED Nextion Display now. These two screens have the exact same resolution, and the default version of the Nextion Firmware from Ian KD8CEC will work on both screen sizes without modification.
If you already have a different sized screen, or want to buy a bigger screen, right from the outset, don’t panic. You may need to make some adjustments to the firmware yourself. This is not difficult – but involves resizing graphics and moving around objects to suit the larger screen area/resolution. Some of us are working on modifications to the Nextion firmware to accommodate 3.2″ and 3.5″ screens. Firmware for these screens is likely to be available quickly.
Screen sizes and resolutions for the BASIC models available on ITEAD’s website are as follows:
The ENHANCED versions available from ITEAD are as follows:
Most of us will choose to buy our Nextion displays from Aliexpress or eBay.
They are available in all sizes and in either BASIC or ENHANCED versions. It is unclear which are OEM versions and which are clones. It probably doesn’t matter.
Look for highly rated suppliers and those with higher shipping volumes. The biggest risks are that your screen arrives cracked, or simply never arrives. You will need some form of redress when goods arrive in a damaged state or simply never arrive, and this is where the intermediaries in eBAY, Aliexpress or Paypal can assist.
