SunSPec 5 - Telemetry System

Week 3 & Week 4 We were tasked to work on the transmission of sensor data within the car with the Bluetooth module, HC-06 FC114, hence eliminating the need of using wiring. We are tasked to use the HC-05 FC-114 (master), and HC-06 FC-114(slave) Bluetooth module and pair them up to allow the communication of Arduino through Bluetooth transmission.  http://www.martyncurrey.com/connecting-2-arduinos-by-bluetooth-using-a-hc-05-and-a-hc-06-pair-bind-and-link/ Figure 1: HC-06 FC-114 Bluetooth Modules The HC-05 module can be used to be set as either the master or the slave, while the HC-06 module can only be set as the slave module. In this case, we will be using the HC-05 as the master and the HC-06 as the slave. To do so, pairing and linking of the modules' required. It is so that the modules will connect to each other automatically when powered up. To do so, the modules first have to be powered up and connected correctly. In this case, we are using th...

We spent some time arranging the components found from T1023 and W13 that will be useful for our project and placed them in boxes.  Figure 1: Telemetry components from W13 Figure 2: Boxes of sorted components We accidentally soldered wires onto the optocoupler board instead of headers and had difficulties removing them, where we broke some of the tracks in the process of removing the wires. We met up with our supervisors on Tuesday, we were then briefed and given the HC-06 FC-114 and RedBear Bluetooth modules to test. It is then found out that HC-06 can only be used as a slave module, whereby the HC-05 is required to be used as a master module. We went to Sim Lim Tower's Amicus Engineering to purchase 3 HC-05 FC-114 Bluetooth modules on Wednesday. We faced several problems with the Arduino IDE after trying to set-up for RedBear. >:( We are able to enter the AT mode for HC-06 FC-114 and upload the code onto the board. Whereby the LEDs on the ...

At the Singapore International Energy Week (SIEW) Exhibition... There were a few booths around us, with all the polytechnics and ITE, NTU, SiT, and SUTD having their own booths. We found two notable groups which may be relevant to the Solar Car, else the course of study, Diploma in Energy Systems & Management (DESM) .  The first one's from Nanyang Polytechnic (NYP) group, which was doing an Intelligent Building Energy Management System (IBEMS), which allows automatic switching of certain equipment such as fan or aircon, according to the temperature. It also automatically slows down certain equipment with the use of variable speed drive (VSD) to reduce energy usage, when exceeding a certain percentage (e.g 80%) of the maximum quoted energy usage a building should use, hence avoiding the surpass of maximum limit and additional charges. Figure 1: NYP IBEMS System The second one's from Nanyang Technological University (NTU) group which was doing a 3-D printed Ele...

Start of MDP  Separating High-Voltage ground and Low-Voltage ground We were brief on the ET0923: Multi-Disciplinary Project module regarding its' means of assessments. We are required to log our weekly progress on the project. We have found out some information on the followings: We found out that we would need an optocoupler (ILD213T 751-1312-1-ND) to isolate the two different circuits we will be using(high voltage & low voltage) to avoid shorting of the circuits and burning the low voltage circuit.  Speed Sensing We have also found out three different possible ways to sense the speed: Motion Detector (Infrared Sensor)  -  It is done by using an infrared sensor to determine the revolution per minute (RPM) of the wheel, then converted to speed through calculations. It is the most accurate method out of the three in finding the speed. However, there is no place to mount the sensor. Pulses from motor  - The motor contr...

Week 2 A simple voltage sensing circuit is built by making use of the voltage divider theorem, whereby  Vout = [ {R2 / (R1+R2)] * Vin ]. We had previously experimented with this circuit where R1 is of value 980K while R2 is of value 10K, the voltage display was more inaccurate from the calculated voltage output as the accuracy was around  +/- 1V, as compared to the current accuracy of  +/- 0.4V . We begin experimenting and replaced the R1 with the value of 100K, only then did the circuit start displaying more accurate Voltage values.                     Figure 1: Voltage Divider Theorem Figure 2: Voltage Sensing Circuit The circuit is tested with a voltage output of 5V from the DC Power Supply, 4.72V is then being sensed by the circuit. Whereas for a voltage of 10V, a 9.49V is being sensed. This shows that the circuit is only accurate up to a certain extent, and can be improved.  ...

Recap: Current Sensor testing during the holiday training During the 6 week holidays, we came back to school for 4 weeks to learn more about the different disciplinaries involved in the project. After a few weeks, we were officially assigned under the Telemetry system for the solar car. We started experimenting with the different current sensors that the previous Telemetry group were using for SunSPec 4. The current sensor model used for SunSPec 5 are AMPLoc AMP50 current sensor. We begin coding with reference from online sources that had set-up circuits with the current sensor. We have found out that most of the online examples were using the invasive type of sensors such as the ACS-712, instead of non-invasive types such as AMPloc. 

Week 1 Figure 1: Current Sensors We made some minor adjustments to the code as the sensitivity setting varies with different model. We have used the AMPloc AMP25 for testing purposes, and the code we came up with is as shown below: /* current sensor testing code */ #include LiquidCrystal lcd(12, 11, 5, 4, 3, 2); const int analogIn = A0; int mVperAmp = 37; // ACS712 - use 100 for 20A Module and 66 for 30A Module, AMPLOC - use 37 for 25A and 23 for 50A int RawValue= 0; int ACSoffset = 2500; double Voltage = 0.0; double Amps = 0.0; void setup() { Serial.begin(9600); lcd.begin(16,2); } void loop() { RawValue = analogRead(A0); Voltage = (RawValue / 1023.0) * 5000; // Gets you mV Amps = ((Voltage - ACSoffset) / mVperAmp); if ( (Voltage > 2520) || (Voltage < amps="); lcd.print(Amps,3); delay (2000); } else { lcd.clear(); lcd.setCursor (3,0); Serial.println(" aw="" delay="" input="" lcd.pri...

Week 2 - Small Update The optocoupler circuit is being tested as of right now using a simple circuit (pics of circuit and code to come later being edited). The optocoupler or opto-isolator works by the opto-isolator IC sending a signal from a Low Voltage (LV) circuit to the High Voltage (HV) circuit.  This allows isolation between the two circuits as connecting a HV ground with a LV circuit will result in damage to the LV circuit, so the opto-isolator is essential to avoid damage and burning of the Arduino when we test it with HV circuits later on. The optocoupler is normally used in applications such as allowing a microcontroller to control servos or other motors that use a higher voltage than the TTL logic on the (3.3V or 5V) microcontroller. Source: http://www.sgbotic.com/index.php?dispatch=products.view&product_id=402 We tested the optocoupler using a DC power supply, a simple breadboard circuit, and Arduino to verify the signal sent from a LV circuit to a HV...