Ksenia Kondrashova
Measuring air flow, relative humidity & temperature, then showing results at TFT
Dependencies: FT800_2 HYT mbed
Air flow is measured with FS7 sensor by IST-AG, humidity & temperature are measured by HYT-271 sensor by IST. Graphs displayed it TFT by Riverdi via graphical controller FFT801.
Hardware
- HYT-271 / HYT-221 / HYT-939 humidity and temperature sensor by IST-AG
- FS7 gas flow sensor by IST-AG
- FS-flowmodule for FS7 sensors
- TFT module uxTouch by Riverdi
- Break Out Board 20 by Riverdi
- Any mbed platform with I2C interface, SPI interface, 2 free GPIO for PD and INT signals and one ADC input.
For documentation on the FT800 library, please refer to the library pages.
Connection
MCU-board to TFT-module
MCU-board is connected to TFT-module via Break Out Board. You need 6 signals to connect: SCK, MOSI and MISO are connected to a SPI channel, SS is the chip select signal, PD work as powerdown and INT for interrupts from TFT to MCU.
You have to connect VDD to BLVDD at Break Out Board if you use the board:
MCU-board to HYT sensor
MCU-board is connected to sensor via I2C. Remember to use pull-up resisrors there:
MCU-board to FS7 sensor
MCU-board is connected to sensor via FS flowmodule. FS-flowmodul is a PCB implementing bridge circuit which is necessary for FS7.
Diff: main.cpp
- Revision:
- 0:3f440c2facb0
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Thu Mar 16 08:58:18 2017 +0000
@@ -0,0 +1,88 @@
+#include "mbed.h"
+#include "FT_Platform.h"
+#include "HYT.h"
+#include "Display.h"
+
+HYT SENSOR(PD6, PD7); // sda, scl [efm32hg_stk3400]
+FT800 TFT(PE10, PE11, PE12, PE13, PA1, PB11); // mosi, miso, sck, ss, int, pd [efm32hg_stk3400]
+AnalogIn ADC(PD4); // [efm32hg_stk3400]
+
+Display disp(&TFT);
+
+uint8_t humidity;
+float flow;
+int8_t temperature;
+
+#define HUMIDITY_CORRECTION 15
+#define TEMPERATURE_CORRECTION -1
+
+/*************************************************************************************************************************/
+float calculateFlow(uint16_t resultADC)
+{
+ uint16_t flowVoltage;
+ if ((resultADC / 1000) - 32 >= 0) {
+ flowVoltage = (resultADC / 1000) - 32;
+ } else {
+ flowVoltage = 0;
+ }
+
+ float voltageToSpeed[31] = { 0, 0, 0, 0.1, 0.1, 0.1, 0.2, 0.2, 0.3, 0.3,
+ 0.4, 0.5, 0.6, 0.7, 0.8, 1.0, 1.2, 1.5, 2.0, 2.3, 2.8, 3.2, 3.9,
+ 4.5, 5.1, 5.8, 6.5, 7.4, 8.2, 9.1, 10
+ };
+ float flowSpeed = voltageToSpeed[flowVoltage];
+
+ return flowSpeed;
+}
+
+/*************************************************************************************************************************/
+uint8_t calculateHumidity(uint8_t humidityFromHYT)
+{
+ uint8_t humidityFinal;
+ if (humidityFromHYT + 15 >= 100) {
+ humidityFinal = 100;
+ } else {
+ humidityFinal = humidityFromHYT + HUMIDITY_CORRECTION;
+ }
+
+ return humidityFinal;
+}
+
+/*************************************************************************************************************************/
+int8_t calculateTemperature(int8_t temperatureFromHYT)
+{
+ return temperatureFromHYT + TEMPERATURE_CORRECTION;
+}
+
+/**************************************************************************************************************************/
+int main()
+{
+ disp.Calibration();
+
+ disp.LoadImagesAndFonts();
+ disp.HandleAllBitmaps();
+
+ disp.showHumidity = 1;
+ disp.showFlow = 1;
+ disp.showTemperature = 1;
+
+ // first point
+ SENSOR.MRCommand();
+ wait_ms(100);
+ SENSOR.DFCommand();
+
+ while (1) {
+ SENSOR.MRCommand();
+
+ humidity = calculateHumidity((uint8_t) SENSOR.humidity);
+ flow = calculateFlow(ADC.read_u16());
+ temperature = calculateTemperature((int8_t) SENSOR.temperature);
+
+ disp.UpdateDataToDraw(humidity, temperature, flow);
+ disp.MainScreen();
+
+ disp.GetTouch();
+
+ SENSOR.DFCommand();
+ }
+}