https://stone-hmi.com/mcu-controller/
Using APM32F103CBT6, 32-bit ARM Cortex-M3 core, Maximum operating frequency of 96MHz, Flash capacity of 128KB
Using STONE serial touch screen portable monitor, the hardware department decided to use NXP’s 32-bit microprocessor chip as the whole machine monitoring, ECG analysis, control center, by ECG bioelectricity acquisition amplification, right leg drive, import MIT ECG database to do an algorithm, but also monitor SpO2 sensor electrical signal, blood pressure, respiratory electrical signal amplification, and filtering processing, through high-speed baud rate communication, drive STONE serial touch screen to display waveform and parameter changes in real-time, and compare with a reference value to make a judgment, and monitor and alarm the changes of human body parameters. If there is a range deviation, it automatically issues voice prompts.
The new version of the STONE serial touch screen perfectly supports curve depiction and display, the communication protocol is simple and easy to remember, microcontroller engineers can use it after reading the manual, there are many examples of drivers in the command set, directly copied to modify the name and parameters can be used. Serial connection is simple, you can use the official adapter board, whether it is a direct serial connection or USB to serial, it is very convenient and easy to use. The monitor displays multiple groups of vital parameters at the same time, especially 3 curves that are dynamically drawn and displayed at the same time very smoothly, and should be able to draw more groups of curve graphics at the same time, you can try as needed. Of course, the command set curve function has an example of multiple data pushed at the same time, but the actual use of the current hardware does not respond, I hope the official can be optimized as soon as possible. It may also be solved by updating the firmware. For this new version of the drawing curve function, I first tried how can not be tuned out, and finally learned that the serial screen has a new firmware, brushed the new firmware to see the “real face of the mountain”. Seeing the smooth ECG curve coming out of the serial screen with the firmware brushed, the mood is happy, huh ……
The design picture of this project is shown in Figure (1). The interface is based on a STWI101WT-01 serial screen with 1024*600 resolution, the left side shows 2/3 of the waveform curve and the right 1/3 shows the value.
This article will focus on the creation and depiction of the curve chart view. It is completely according to the production process of the project demo, with no classification, maybe you feel messy, but it is the real process of real development.
First, We Decided To Fix The Curve Depiction Of ECG.
This demo simulates a 75bpm heart rate, which is equivalent to an 800ms heartbeat, i.e. one point every 40ms, one cycle every 20 points, based on the whole chart view control X axis divided into 100 equal parts, 4s waveform per screen, screen refresh rate 25Hz, looks very smooth. The line series element of this chart view control is set to smooth = false (ECG waveform is sharp), the lower envelope is not displayed, and the point marker is not displayed. area. Here see Figure (4), min = 0, max = 140 for the Y axis, the maximum value given in the program is 130, and the range is relatively full. See Figure (2) – Figure (7) for other parameters, which are set for chart view1 and its elements X axis1, Yaxis2, bar series1, and line series1. We choose transparent rgba (0,0,0,0) for the bg color of the chart view control, which reveals the base color (black), and other controls, such as view, have the same characteristics.
