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.
Figure (1) Project Design Expected Interface
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.
Figure (2) Property settings of chart view1
Figure (3) X axis1 property setting of chart view1
Figure (4) Y axis1 property setting of chart view1
Figure (5) bar series1 property setting of chart view1
Figure (6) The line series1 property setting of chart view111
Figure (7) line series1 property setting of chart view12