--- description: Pressure sensor using the Wio terminal title: Pressure sensor using the Wio terminal keywords: - Wio_terminal Tutorial image: https://files.seeedstudio.com/wiki/wiki-platform/S-tempor.png slug: /Barometric-Pressure-sensor-using-the-Wio-terminal last_update: date: 1/31/2023 author: jianjing Huang --- # High Precision Barometric Pressure sensor using the Wio terminal
## Overview The demo shows that the Grove- high precision pressure sensor DPS310 is fully compatible with the Wio terminal, and its measurement has high precision. ## Features - The range of normal atmospheric pressure values can be display by the dial colour - with the time to display the temperature degrees - High precision barometric pressure and temperature detection ## Hardware - [**Wio terminal**](https://www.seeedstudio.com/Wio-Terminal-p-4509.html) - [**Grove- high precision pressure sensor DPS310**](https://www.seeedstudio.com/Grove-High-Precision-Barometer-Sensor-DPS310-p-4397.html) ### Hardware Connection
## software if you do not have The Arduino IDE, please view [**The Get Started with Wio Terminal**](https://wiki.seeedstudio.com/Wio-Terminal-Getting-Started/) - Install the LCD screen Library `Seeed_Arduino_LCD`, please visit [Wio Terminal LCD](https://wiki.seeedstudio.com/Wio-Terminal-LCD-Overview/). - Install the DPS310-Pressure-Sensor Library `#include `, please visit [DPS310-Pressure-Sensor](https://wiki.seeedstudio.com/Grove-High-Precision-Barometric-Pressure-Sensor-DPS310/). ## Code ```cpp #include #include #include // Hardware-specific library TFT_eSPI tft = TFT_eSPI(); #define TFT_GREY 0x5AEB #define LOOP_PERIOD 35 // Display updates every 35 ms Dps310 Dps310PressureSensor = Dps310(); #define M_SIZE 1.4 TFT_eSprite spr = TFT_eSprite(&tft); // Sprite float ltx = 0; // Saved x coord of bottom of needle uint16_t osx = M_SIZE * 120, osy = M_SIZE * 120; // Saved x & y coords uint32_t updateTime = 0; // time for next update int old_analog = -999; // Value last displayed int value[6] = {0, 0, 0, 0, 0, 0}; int d = 0; void setup(void) { tft.begin(); tft.init(); tft.setRotation(3); Serial.begin(57600); // For debug tft.fillScreen(TFT_WHITE); spr.createSprite(TFT_HEIGHT,TFT_WIDTH); spr.setRotation(3); Dps310PressureSensor.begin(Wire); analogMeter(); // Draw analogue meter updateTime = millis(); // Next update time } void loop() { float temperature; float pressure; uint8_t oversampling = 7; int16_t ret; ret = Dps310PressureSensor.measureTempOnce(temperature, oversampling); ret = Dps310PressureSensor.measurePressureOnce(pressure, oversampling); Serial.println(pressure); if (updateTime <= millis()) { updateTime = millis() + 35; // Update emter every 35 milliseconds // Create a Sine wave for testing d += 4; if (d >= 360) { d = 0; } //////////////////////////////////////////////////////// // this is a excmple, you just need to del '- 100050' //////////////////////////////////////////////////////// plotNeedle(pressure-100050, 0); // It takes between 2 and 12ms to replot the needle with zero delay } delay(100); spr.fillSprite(TFT_WHITE); spr.createSprite(250, 40); spr.fillSprite(TFT_WHITE); spr.setTextColor(TFT_BLACK, TFT_WHITE); spr.setFreeFont(&FreeSansBoldOblique12pt7b); spr.drawNumber(temperature, 0, 0); spr.drawString(" °C", 30, 0); spr.drawNumber(pressure, 120,0); spr.drawString("Pa", 210,0); spr.pushSprite(30, 190); spr.deleteSprite(); } // ######################################################################### // Draw the analogue meter on the screen // ######################################################################### void analogMeter() { // Meter outline tft.fillRect(0, 0, M_SIZE * 239, M_SIZE * 126, TFT_GREY); tft.fillRect(5, 3, M_SIZE * 230, M_SIZE * 119, TFT_WHITE); tft.setTextColor(TFT_BLACK); // Text colour // Draw ticks every 5 degrees from -50 to +50 degrees (100 deg. FSD swing) for (int i = -50; i < 51; i += 5) { // Long scale tick length int tl = 15; // Coodinates of tick to draw float sx = cos((i - 90) * 0.0174532925); float sy = sin((i - 90) * 0.0174532925); uint16_t x0 = sx * (M_SIZE * 100 + tl) + M_SIZE * 120; uint16_t y0 = sy * (M_SIZE * 100 + tl) + M_SIZE * 140; uint16_t x1 = sx * M_SIZE * 100 + M_SIZE * 120; uint16_t y1 = sy * M_SIZE * 100 + M_SIZE * 140; // Coordinates of next tick for zone fill float sx2 = cos((i + 5 - 90) * 0.0174532925); float sy2 = sin((i + 5 - 90) * 0.0174532925); int x2 = sx2 * (M_SIZE * 100 + tl) + M_SIZE * 120; int y2 = sy2 * (M_SIZE * 100 + tl) + M_SIZE * 140; int x3 = sx2 * M_SIZE * 100 + M_SIZE * 120; int y3 = sy2 * M_SIZE * 100 + M_SIZE * 140; // Yellow zone limits if (i >= -50 && i < -25) { tft.fillTriangle(x0, y0, x1, y1, x2, y2, TFT_GREEN); tft.fillTriangle(x1, y1, x2, y2, x3, y3, TFT_GREEN); } if (i >= -25 && i < 0) { tft.fillTriangle(x0, y0, x1, y1, x2, y2, TFT_YELLOW); tft.fillTriangle(x1, y1, x2, y2, x3, y3, TFT_YELLOW); } // Green zone limits if (i >= 0 && i < 25) { tft.fillTriangle(x0, y0, x1, y1, x2, y2, TFT_RED); tft.fillTriangle(x1, y1, x2, y2, x3, y3, TFT_RED); } // Orange zone limits if (i >= 25 && i < 50) { tft.fillTriangle(x0, y0, x1, y1, x2, y2, TFT_RED); tft.fillTriangle(x1, y1, x2, y2, x3, y3, TFT_RED); } // Short scale tick length if (i % 25 != 0) { tl = 8; } // Recalculate coords incase tick lenght changed x0 = sx * (M_SIZE * 100 + tl) + M_SIZE * 120; y0 = sy * (M_SIZE * 100 + tl) + M_SIZE * 140; x1 = sx * M_SIZE * 100 + M_SIZE * 120; y1 = sy * M_SIZE * 100 + M_SIZE * 140; // Draw tick tft.drawLine(x0, y0, x1, y1, TFT_BLACK); // Check if labels should be drawn, with position tweaks if (i % 25 == 0) { // Calculate label positions x0 = sx * (M_SIZE * 100 + tl + 10) + M_SIZE * 120; y0 = sy * (M_SIZE * 100 + tl + 10) + M_SIZE * 140; //////////////////////////////////////////////////////////// // In here, you can change the dial plate //////////////////////////////////////////////////////////// switch (i / 25) { case -2: tft.drawCentreString("100000", x0, y0 - 12, 2); break; case -1: tft.drawCentreString("100025", x0, y0 - 9, 2); break; case 0: tft.drawCentreString("100050", x0, y0 - 7, 2); break; case 1: tft.drawCentreString("100075", x0, y0 - 9, 2); break; case 2: tft.drawCentreString("100100", x0, y0 - 12, 2); break; } } // Now draw the arc of the scale sx = cos((i + 5 - 90) * 0.0174532925); sy = sin((i + 5 - 90) * 0.0174532925); x0 = sx * M_SIZE * 100 + M_SIZE * 120; y0 = sy * M_SIZE * 100 + M_SIZE * 140; // Draw scale arc, don't draw the last part if (i < 50) { tft.drawLine(x0, y0, x1, y1, TFT_BLACK); } } //tft.drawString("%RH", M_SIZE * (5 + 230 - 40), M_SIZE * (119 - 20), 2); // Units at bottom right tft.drawCentreString("K/Pa", M_SIZE * 120, M_SIZE * 80, 4); // Comment out to avoid font 4 tft.drawRect(5, 3, M_SIZE * 230, M_SIZE * 119, TFT_BLACK); // Draw bezel line plotNeedle(0, 0); // Put meter needle at 0 } // ######################################################################### // Update needle position // This function is blocking while needle moves, time depends on ms_delay // 10ms minimises needle flicker if text is drawn within needle sweep area // Smaller values OK if text not in sweep area, zero for instant movement but // does not look realistic... (note: 100 increments for full scale deflection) // ######################################################################### void plotNeedle(int value, byte ms_delay) { if (value < -10) { value = -10; // Limit value to emulate needle end stops } if (value > 110) { value = 110; } // Move the needle until new value reached while (!(value == old_analog)) { if (old_analog < value) { old_analog++; } else { old_analog--; } if (ms_delay == 0) { old_analog = value; // Update immediately if delay is 0 } float sdeg = map(old_analog, -10, 110, -150, -30); // Map value to angle // Calcualte tip of needle coords float sx = cos(sdeg * 0.0174532925); float sy = sin(sdeg * 0.0174532925); // Calculate x delta of needle start (does not start at pivot point) float tx = tan((sdeg + 90) * 0.0174532925); // Erase old needle image tft.drawLine(M_SIZE * (120 + 20 * ltx - 1), M_SIZE * (140 - 20), osx - 1, osy, TFT_WHITE); tft.drawLine(M_SIZE * (120 + 20 * ltx), M_SIZE * (140 - 20), osx, osy, TFT_WHITE); tft.drawLine(M_SIZE * (120 + 20 * ltx + 1), M_SIZE * (140 - 20), osx + 1, osy, TFT_WHITE); // Re-plot text under needle tft.setTextColor(TFT_BLACK); tft.drawCentreString("K/Pa", M_SIZE * 120, M_SIZE * 80, 4); // // Comment out to avoid font 4 // Store new needle end coords for next erase ltx = tx; osx = M_SIZE * (sx * 98 + 120); osy = M_SIZE * (sy * 98 + 140); // Draw the needle in the new postion, magenta makes needle a bit bolder // draws 3 lines to thicken needle tft.drawLine(M_SIZE * (120 + 20 * ltx - 1), M_SIZE * (140 - 20), osx - 1, osy, TFT_RED); tft.drawLine(M_SIZE * (120 + 20 * ltx), M_SIZE * (140 - 20), osx, osy, TFT_MAGENTA); tft.drawLine(M_SIZE * (120 + 20 * ltx + 1), M_SIZE * (140 - 20), osx + 1, osy, TFT_RED); // Slow needle down slightly as it approaches new postion if (abs(old_analog - value) < 10) { ms_delay += ms_delay / 5; } // Wait before next update delay(ms_delay); } } ```