Our Blog

609, 2021

The Sunday Blog: Nextion HMI as a full featured HEX calculator

By |September 6th, 2021|

I'm for sure not the only one among all Nextion HMI users who does a lot of embedded programming. In the old times, with 8bit MCUs, most of the calculus with numbers between 0 and 255 or between -128 and +127 could easily be done in mind or with pencil and paper. But then came the 16 and 32bit MCUs and things like calculating jump and port addresses or bit masks just got more difficult. Not everyone could afford a HP-16C programmer's pocket calculator back in the mid 1980ies and they are not longer in production, today. So, I thought by myself "That could be a nice blog project, we have a 32bit Cortex M0 MCU inside the Nextion HMI, that should be doable!". And it was doable. I made a few design considerations, first: Not using RPN, HP's uncommon but efficient input system, but "classic" algebraic input. Then, I listed and ordered all the functions I wanted to have and all the keys I wanted to see on the screen. This helped me to divide everything up into 3 groups: Entry keys (0-9, A-F) which allow entering numbers into the main display register (X), immediate function keys which don't require waiting for a second operand: CLR, CE, XY, VIEW, +/- (change sign), ! (bitwise NOT), SGN (extract the sign), and, as a special case "=". And finally, the third group, operator keys like +, -, *, /, & (bitwise AND), | (bitwise OR), ^ (bitwise XOR), % (modulo), > (arithmetic shift right).

3008, 2021

The Sunday Blog: Advanced programming – Parsing files from SD card

By |August 30th, 2021|

Sometimes, we'd like to change static content of our Nextion HMI, be it text or colors on the screen, be it to initialize variables or to control variants in our program. And all - preferably - without compiling and uploading a new tft file. Why not use the SD card, save a configuration file on it, let the Nextion parse it and adapt its program at the next startup? That's possible with the FileStream component which exists for the Intelligent (P) series Nextion HMI displays!

2308, 2021

The Sunday Blog: Advanced programming techniques – Nextion HMI as a serial monitor (2)

By |August 23rd, 2021|

Part 1 of this series was already published in April, explaining the basics of the protocol reparse mode and using a Nextion HMI display as "simple" serial monitor. At the end, I promised a follow-up to show how a Nextion HMI could parse and decode the return data of another one - for sure a helpful debug tool. But then, we got the new Intelligent P series displays, followed by new editor releases with new features and then the new Discovery F series. All this led to intensive beta testing work and finally to me blogging about these more actual topics. But now, it's time to keep my promise and to move on.

1508, 2021

The Sunday Blog: New Discovery HMI available – And a first specific Demo project

By |August 15th, 2021|

These are extremely good news: The new Discovery (F) series HMIs are finally available! Attentive readers have already seen my announcement a few weeks before, stating that ongoing component shortages and flamboyant component (CPU) prices made it necessary to offer a drop-in alternative for the smaller Basic (T) series HMIs. But my dear Chinese colleagues went beyond that: The new Discovery HMIs are less expensive, more performant, and more energy efficient than their Basic siblings!

208, 2021

The Sunday Blog: Energy efficient design with Nextion HMI – Portable and wearable designs

By |August 2nd, 2021|

A small Nextion HMI display, an Arduino-like microprocessor board, one or more sensors, and all that in a small housing working on batteries. Doesn't that sound appealing? The answer is clearly "yes". But is it realistic? Again, "yes"! But there are several aspects to consider on the hardware and the software side to prevent your 18350 Lithium-Ion battery to be emptied within half an hour. In this article, we'll try to shed some light on these considerations and I'll give you a few hints.