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main.cpp@1:011f0bdaa7f5, 2022-07-17 (annotated)
- Committer:
- marietjie
- Date:
- Sun Jul 17 18:07:55 2022 +0000
- Revision:
- 1:011f0bdaa7f5
- Parent:
- 0:28f2dba63d6c
- Child:
- 2:11714802a55d
rev1;
Who changed what in which revision?
| User | Revision | Line number | New contents of line | 
|---|---|---|---|
| marietjie | 0:28f2dba63d6c | 1 | /*---------------------------------------------------------- | 
| marietjie | 1:011f0bdaa7f5 | 2 | A fictional IoT-enabled Ice cream machine dispenser arm state | 
| marietjie | 1:011f0bdaa7f5 | 3 | The machine runs with an STM32F4 MCU; The Nucleo-F410RB is chosen for implementation, as it has serial communication, several digital outputs and 16 channel 12-bit ADC and more | 
| marietjie | 0:28f2dba63d6c | 4 | |
| marietjie | 1:011f0bdaa7f5 | 5 | Operation: Ice cream machine dispenser arm sensor provides 0-3.3 V (assume based on operating voltage | 
| marietjie | 0:28f2dba63d6c | 6 | of MCU) to one ADC pin on STM32F4 MCU. Voltage is based on position of dispenser arm. | 
| marietjie | 0:28f2dba63d6c | 7 | - voltage > 1.65V implies the arm is pressed down | 
| marietjie | 0:28f2dba63d6c | 8 | - voltage < 1.65V implies the arm is released | 
| marietjie | 1:011f0bdaa7f5 | 9 | To prevent rapid switching, hysteresis is introduced with a counter function, if arm is pressed down for more than 5 seconds, the digital output will go high. | 
| marietjie | 0:28f2dba63d6c | 10 | |
| marietjie | 0:28f2dba63d6c | 11 | Requirements: | 
| marietjie | 0:28f2dba63d6c | 12 | 1. Read ADC value and print over serial port | 
| marietjie | 0:28f2dba63d6c | 13 | 2. Digital output pin high if voltage>1.65V | 
| marietjie | 0:28f2dba63d6c | 14 | 3. Digital output pin low if voltage <1.65V | 
| marietjie | 0:28f2dba63d6c | 15 | |
| marietjie | 0:28f2dba63d6c | 16 | Assumptions: | 
| marietjie | 0:28f2dba63d6c | 17 | 1. The code can run at a low speed as ice cream machines do not dispense ice cream quickly | 
| marietjie | 0:28f2dba63d6c | 18 | 2. Low accuracy and low resolution due to nature of ice cream machine dispensing arms | 
| marietjie | 0:28f2dba63d6c | 19 | |
| marietjie | 0:28f2dba63d6c | 20 | Additional features | 
| marietjie | 0:28f2dba63d6c | 21 | 1. Temperature of ice cream mixture is important, assume temperature sensor can provide analogue | 
| marietjie | 0:28f2dba63d6c | 22 | voltage to MCU | 
| marietjie | 0:28f2dba63d6c | 23 | 2. Level of ice cream mix in machine is important, assume a sensor can detect when the mixture drops | 
| marietjie | 0:28f2dba63d6c | 24 | below a certain level, also be analogue voltage sensor output | 
| marietjie | 0:28f2dba63d6c | 25 | |
| marietjie | 0:28f2dba63d6c | 26 | ADC data on MCU: | 
| marietjie | 0:28f2dba63d6c | 27 | Value from 0.0 to 1.0, depending on input voltage between 0.0V and | 
| marietjie | 0:28f2dba63d6c | 28 | 3.3V; ADC default settings | 
| marietjie | 0:28f2dba63d6c | 29 | ------------------------------------------------------------*/ | 
| marietjie | 0:28f2dba63d6c | 30 | #include "mbed.h" | 
| marietjie | 0:28f2dba63d6c | 31 | Ticker readADC; //Allows timed interval of reading data on ADC lines | 
| marietjie | 0:28f2dba63d6c | 32 | |
| marietjie | 1:011f0bdaa7f5 | 33 | //Serial pc(USBTX, USBRX); | 
| marietjie | 0:28f2dba63d6c | 34 | Serial device(D8, D2); // tx, rx, default settings: 9600 8N1 | 
| marietjie | 0:28f2dba63d6c | 35 | |
| marietjie | 0:28f2dba63d6c | 36 | AnalogIn DispArmIn(A0); //ADC input from dispensing arm | 
| marietjie | 0:28f2dba63d6c | 37 | AnalogIn TempIn(A1); //ADC input from temperature sensor | 
| marietjie | 1:011f0bdaa7f5 | 38 | AnalogIn LevelIn(A2); //ADC input from sensor detecting level | 
| marietjie | 0:28f2dba63d6c | 39 | |
| marietjie | 0:28f2dba63d6c | 40 | float DispArm_data; //Dispenser arm data | 
| marietjie | 0:28f2dba63d6c | 41 | float Temp_data; //Temperature data | 
| marietjie | 0:28f2dba63d6c | 42 | float Level_data; //Mixture level data | 
| marietjie | 0:28f2dba63d6c | 43 | bool ADC_ready; //Indicate data has been read | 
| marietjie | 1:011f0bdaa7f5 | 44 | int counter; //Hysteresis for dispenser arm | 
| marietjie | 0:28f2dba63d6c | 45 | |
| marietjie | 1:011f0bdaa7f5 | 46 | DigitalOut dout(A4); //Digital output to indicate if dispensing arm has crossed the halfway mark | 
| marietjie | 0:28f2dba63d6c | 47 | DigitalOut led(LED2); //Digital output for general use on LED | 
| marietjie | 0:28f2dba63d6c | 48 | |
| marietjie | 0:28f2dba63d6c | 49 | void ReadAnalog() | 
| marietjie | 0:28f2dba63d6c | 50 | { | 
| marietjie | 0:28f2dba63d6c | 51 | //Assume default AnalogIn read settings | 
| marietjie | 0:28f2dba63d6c | 52 | DispArm_data = DispArmIn; | 
| marietjie | 0:28f2dba63d6c | 53 | Temp_data = TempIn; | 
| marietjie | 0:28f2dba63d6c | 54 | Level_data = LevelIn; | 
| marietjie | 0:28f2dba63d6c | 55 | |
| marietjie | 1:011f0bdaa7f5 | 56 | if (DispArm_data>0.5f) //Use counter function to prevent rapid switching | 
| marietjie | 0:28f2dba63d6c | 57 | {//Trigger output pin; Add this section here as it is one of the critical requirements. | 
| marietjie | 0:28f2dba63d6c | 58 | counter++; | 
| marietjie | 0:28f2dba63d6c | 59 | if(counter>5) | 
| marietjie | 0:28f2dba63d6c | 60 | { | 
| marietjie | 0:28f2dba63d6c | 61 | dout = 1; //Arm is pressed down | 
| marietjie | 0:28f2dba63d6c | 62 | counter=0; | 
| marietjie | 1:011f0bdaa7f5 | 63 | } | 
| marietjie | 0:28f2dba63d6c | 64 | } | 
| marietjie | 0:28f2dba63d6c | 65 | else { | 
| marietjie | 0:28f2dba63d6c | 66 | dout=0; //Arm is released | 
| marietjie | 0:28f2dba63d6c | 67 | counter=0; | 
| marietjie | 0:28f2dba63d6c | 68 | } | 
| marietjie | 0:28f2dba63d6c | 69 | ADC_ready=1; //ADC have been read | 
| marietjie | 0:28f2dba63d6c | 70 | } | 
| marietjie | 0:28f2dba63d6c | 71 | |
| marietjie | 0:28f2dba63d6c | 72 | int main() | 
| marietjie | 0:28f2dba63d6c | 73 | { | 
| marietjie | 0:28f2dba63d6c | 74 | //Initialise variables here | 
| marietjie | 0:28f2dba63d6c | 75 | ADC_ready=0; | 
| marietjie | 0:28f2dba63d6c | 76 | counter=0; | 
| marietjie | 0:28f2dba63d6c | 77 | DispArm_data = 0.0; | 
| marietjie | 0:28f2dba63d6c | 78 | Temp_data = 0.0; | 
| marietjie | 0:28f2dba63d6c | 79 | Level_data = 0.0; | 
| marietjie | 1:011f0bdaa7f5 | 80 | |
| marietjie | 1:011f0bdaa7f5 | 81 | readADC.attach(&ReadAnalog, 0.5); // the address of the function attached and the interval (0.5 seconds) | 
| marietjie | 0:28f2dba63d6c | 82 | device.printf("\nIce cream machine state:\n"); | 
| marietjie | 0:28f2dba63d6c | 83 | |
| marietjie | 0:28f2dba63d6c | 84 | while (1) { | 
| marietjie | 0:28f2dba63d6c | 85 | if (ADC_ready) | 
| marietjie | 0:28f2dba63d6c | 86 | { | 
| marietjie | 0:28f2dba63d6c | 87 | //pc.printf("%f \n\r",ADCdata); | 
| marietjie | 0:28f2dba63d6c | 88 | device.printf("Dispenser arm %f \n\r",DispArm_data); | 
| marietjie | 0:28f2dba63d6c | 89 | if(Temp_data>0.7f) | 
| marietjie | 0:28f2dba63d6c | 90 | { | 
| marietjie | 0:28f2dba63d6c | 91 | device.printf("Ice cream mixture not cooling: %f \n\r",Temp_data); | 
| marietjie | 0:28f2dba63d6c | 92 | } | 
| marietjie | 0:28f2dba63d6c | 93 | if (Level_data<0.3f) | 
| marietjie | 0:28f2dba63d6c | 94 | { | 
| marietjie | 0:28f2dba63d6c | 95 | device.printf("Ice cream mixture level low: %f \n\r",Level_data); | 
| marietjie | 0:28f2dba63d6c | 96 | } | 
| marietjie | 0:28f2dba63d6c | 97 | ADC_ready=0; | 
| marietjie | 0:28f2dba63d6c | 98 | } else {} | 
| marietjie | 0:28f2dba63d6c | 99 | wait (0.2f); | 
| marietjie | 0:28f2dba63d6c | 100 | } | 
| marietjie | 0:28f2dba63d6c | 101 | } |