Our plan for Integrated System Build and Test was to combine both the mechanical and electrical elements into one working prototype using the provided hardware to emulate a real torch as closely as possible. Unfortunately due to some quality issues with the torches we received we were delayed substantially, though we have confirmed each of the subsystems works in isolation as intended. A prototype of a individual torch has been built with the existing materials in the meantime.

Mechanical Test Results.

During this phase, the mechanical team continued to finalize the valve model, as well as design a new pole and base for the torch to sit on. The given parts had weak points at all threaded connections, and due to the construction of the base, the entire system does not remain completely vertical.

Torch Body

The threading pipe inserts would often shear if the connected pipes were not completely parallel. Any gust of wind or other small force would surely send the original design toppling down. This redesign required thicker pipes for more threadable area, as well as to increase overall strength of the torch.

Pipe received from customer with aluminum insert vs Aluminum pipe with integrated threading.

Torch Valve

Due to necessary design changes to the body of the torch, valve testing took a little bit of a backseat. Current designs of the valve have a proper seal, but either get stuck in the open or closed position.

Various Valve Tests

Electrical Test Result.

During this phase, the electrical team continued working toward goals of assembling the individual torch electronics. The main focus for this phase was to integrate the solar panel subsystem with a ESP32 client and finish the code to process the level sensor data.

Integration and Testing Solar Panel

During this phase, the solar power subsystem needed to be modified to include an ESP32 client. Space was made on the breadboard located on the pump electronics test bench to set up the prototype. The picture below displays the integrated system which will ultimately be located on each torch.

Each of the colored boxes represents the following:

• Green: ESP32 Client
• Orange: Voltage Regulator Circuit
• Pink: LiPo Charger
• Blue: LiPo Battery
• Red: Solar Panels

First, the solar panel subsystem was tested by observation. The subsystem was placed in the window on a sunny day in the morning and power generation from the panels was observed by the red and green LED on the LiPo charger turning on when in the sunlight. The red LED signals when the battery is being charge while the green LED signals whether there is sufficient light. A quick video showcasing the preliminary testing is located here.

Following this simple observational testing, the test set up was taken outside for more thorough electrical testing. Electrical measurements were taken at the output of the LiPo charger to gather an inital voltage reading from the solar panel generation and a second measurement was taken directly at the pins where the ESP32 was being powered. Essentially, measurements were taken before and after the voltage regulator circuit. Data was collected every hour starting at 9:30am. The data is displayed below:

It was intended to test for a full 12 hours, however, the set up needed to relocated inside due to rain in the afternoon. No further measurements occurred after 1:30pm. Every hour, connection to the ESP32 via WIFI was tested. This was determined based on observations of the list of available WIFI networks on an iPhone. For all of the tests conducted, there was no observation of the ESP32 working because the WIFI access point was not available. In order to achieve supplying 3-3.3V to the ESP32 so it can function properly, the regulator circuit was removed from the prototype and a direct connection between the LiPo Charger output pins and the ESP32 input pins were made. This was completed once the test set up was moved inside around 1:45pm. Therefore, voltage from the charged battery was used to supply the voltage to the ESP32. Using a multimeter, voltage measurements were taken at the LiPo Charger output pins and the ESP32 input pins. The voltage reading was recorded as 3.29V at both locations. This means there was no voltage drop across the jumper wires. By removing the voltage regulator, the ESP32 access point was accessible via an iPhone as seen in the picture below because there was sufficient voltage being supplied to the ESP32.

Now that the circuit is working with the ideal functionality, the solar subsystem was removed from the base station breadboard to a separate breadboard, so further integration and testing can commence. Also, using extra parts another LiPo charger circuit was created on a prototype board to scale down the size of the circuit and prepare for multiple torch testing as seen below. Currently, the assembly contains only the LiPo charger wired to where the ESP32 client should connect and the battery for the solar power to charge.

To prepare for full integration testing, the original ESP32-C3-Mini model used in testing was exchanged for a ESP32-WROVER model so it can collect capacitive data from the level sensor. The final prototype of the solar subsystem is displayed below with the main change being the replacement of the new ESP32 and removal of the voltage regulator circuit.

Micro-Controller Programming: Preliminary Sensor Testing

Since Phase 6, the objective for this phase was to continue making progress coding the ESP32 client and server. The team aimed to send data collected from the capacitive sensor made from copper tape back and forth between the client and server. A couple notable changes since Phase 6 includes implementing a new ESP32 dev kit into our design. For each of the individual torch (client ESP32), a ESP32-WROVER model will be used, so it can connect capacitive measurements. The ESP32-C3-Mini model used previously for both the client and the server will only be used in the future as the server due to the lack of capacitive sensing capabilities.

The major accomplishment for the code for this phase was getting a server and client to be able to fully connect and be able to send over data over the same network. The previous phase had shown just a server being set up with a phone being able to connect to the server. For this phase we were able to get a client (ESP32-WROVER) to also connect to the server and hook up a sensor to it and be able to transmit data read from the capacitive sensor. Since we have taken the approach of using a point-to-point Wi-Fi connection, we are sending over data by POST and GET requests.

Once the code was implemented to add capacitive sensing capabilities via the copper tape sensor, testing to discover the appropriate threshold voltage began. Using a metal bowl, some copper tape was applied to the outskirts of the bowl with a wire attached to the tape as seen in the picture below. The wire connected to the bowl was placed in Pin 4 of the ESP32, so that data values for capacitive sensing could be collected. The team simulated capacitive sensing on the client by placing water into the bowl. Simply by adding water the team observed little change in values. The next test was to place a finger in the bowl which showed a larger change. The team predicts that with a liquid of a larger viscosity we will be able to detect a large change in capacitance compared to water.

Individual Torch Integration and Testing

After simulating the solar system and the capacitive sensor individually, the next task was to integrate the two together so that we would see an individual torch working. Minor adjustments to the solar system breadboard were made in order to accommodate the new ESP32 client and to integrate capacitive sensing. The pictures below shown the building process and final results of the build:

(a) torch tank with capacitive sensing leads and power and ground wires

(b) full torch assembly with capacitive sensing torch tank and tubing

(c) new solar assembly attached to torch tank

(d) breadboard containing solar power circuit and ESP32 Client

(e) full torch head assembly containing all individual torch electronics

After the torch was fully assembled with the subsystem prototypes, the torch was taken outside to test on October 27th. The weather was partly cloudy but had adequate sun in the morning to test. Once placed in the grassy area between the James Gleason building and Booth Hall, we immediately saw the green LED on the LiPo charger light up signaling power was being generated from the solar panels. After several seconds the red LED turned on indicating the LiPo battery was charging. Several seconds after that, the red LED on the ESP32 was turned on. Both red LED were dim and flickered compare to when a constant voltage source was applied such as voltage from a computer when programming the ESP32. A picture of the lit LED are seen below. Thus, voltage measurements were taken using a multimeter at the output pins of the LiPo charger and the input pins on the ESP32. At both, a reading of approximately 3.0V was recorded, however, the reading was very unstable. Next a reading at the solar panel input leads were taken and record to be approximately 5V which was significantly higher. Reasoning for this dramatic difference may be attributed to the battery not being able to charge simultaneously with trying to power up the ESP32.

Next, testing to see if data could be transmitted to the server and read was conducted. Unfortunately, we could not do this wirelessly which was most likely due to the lack of a steady voltage. Further troubleshooting will occur in Phase 8. Instead, to ensure that the set up actually works we made a hard connection from the ESP32 client to the computer. A server was not used to receive the values, and instead, the capacitive sensing values were read from the connection between the computer and ESP32 client. Compared to the values during the bowl testing which range from 30-50, the values of capacitance were much smaller. Capacitive values sent from the server via the client are shown below with the corresponding source of capacitance as seen below in the table.

Possible reasoning behind the low values are hypothesized to be from the smaller tank sized used. During this test we noticed by even touching the pole of the ESP32 the capacitance would change which is a concern due to the small range of detected capacitances. For Phase 8, we will explore the display value capabilities in efforts to acquire a bigger range of value that will avoid falsely triggering the pump to refuel.

• Pre-read: P21389_IntegratedSystemBuild&Test_Preread (3).pdf
• Presentation: Phase VII_ Review.pdf

Here is an outline of tasks that we aim to accomplish in order to meet our objective:

• General
  • Create a schedule outline to test system with citronella oil
• Mechanical
  • Finish manufacturing a new torch body for testing purposes
  • Resume work and testing of tank refueling valve
• Electrical
  • Research/select a new LiPo Charger with a switching circuit for charging and discharging
  • Improve precision of reporting capacitive values to create bigger distinction between "high" and "low" levels of fuel
• Administrative
  • Seek approval for burning torch on campus

(three week plans here):

Our plan for Integrated System Build and Test was to combine both the mechanical and electrical elements into one working prototype using the provided hardware to emulate a real torch as closely as possible. Unfortunately due to some quality issues with the torches we received we were delayed substantially, though we have confirmed each of the subsystems works in isolation as intended. A prototype of a individual torch has been built with the existing materials in the meantime.

Mechanical Test Results.

During this phase, the mechanical team continued to finalize the valve model, as well as design a new pole and base for the torch to sit on. The given parts had weak points at all threaded connections, and due to the construction of the base, the entire system does not remain completely vertical.

Torch Body

The threading pipe inserts would often shear if the connected pipes were not completely parallel. Any gust of wind or other small force would surely send the original design toppling down. This redesign required thicker pipes for more threadable area, as well as to increase overall strength of the torch.

Pipe received from customer with aluminum insert vs Aluminum pipe with integrated threading.

Torch Valve

Due to necessary design changes to the body of the torch, valve testing took a little bit of a backseat. Current designs of the valve have a proper seal, but either get stuck in the open or closed position.

Various Valve Tests

Electrical Test Result.

During this phase, the electrical team continued working toward goals of assembling the individual torch electronics. The main focus for this phase was to integrate the solar panel subsystem with a ESP32 client and finish the code to process the level sensor data.

Integration and Testing Solar Panel

During this phase, the solar power subsystem needed to be modified to include an ESP32 client. Space was made on the breadboard located on the pump electronics test bench to set up the prototype. The picture below displays the integrated system which will ultimately be located on each torch.

Each of the colored boxes represents the following:

• Green: ESP32 Client
• Orange: Voltage Regulator Circuit
• Pink: LiPo Charger
• Blue: LiPo Battery
• Red: Solar Panels

First, the solar panel subsystem was tested by observation. The subsystem was placed in the window on a sunny day in the morning and power generation from the panels was observed by the red and green LED on the LiPo charger turning on when in the sunlight. The red LED signals when the battery is being charge while the green LED signals whether there is sufficient light. A quick video showcasing the preliminary testing is located here.

Following this simple observational testing, the test set up was taken outside for more thorough electrical testing. Electrical measurements were taken at the output of the LiPo charger to gather an inital voltage reading from the solar panel generation and a second measurement was taken directly at the pins where the ESP32 was being powered. Essentially, measurements were taken before and after the voltage regulator circuit. Data was collected every hour starting at 9:30am. The data is displayed below:

It was intended to test for a full 12 hours, however, the set up needed to relocated inside due to rain in the afternoon. No further measurements occurred after 1:30pm. Every hour, connection to the ESP32 via WIFI was tested. This was determined based on observations of the list of available WIFI networks on an iPhone. For all of the tests conducted, there was no observation of the ESP32 working because the WIFI access point was not available. In order to achieve supplying 3-3.3V to the ESP32 so it can function properly, the regulator circuit was removed from the prototype and a direct connection between the LiPo Charger output pins and the ESP32 input pins were made. This was completed once the test set up was moved inside around 1:45pm. Therefore, voltage from the charged battery was used to supply the voltage to the ESP32. Using a multimeter, voltage measurements were taken at the LiPo Charger output pins and the ESP32 input pins. The voltage reading was recorded as 3.29V at both locations. This means there was no voltage drop across the jumper wires. By removing the voltage regulator, the ESP32 access point was accessible via an iPhone as seen in the picture below because there was sufficient voltage being supplied to the ESP32.

Now that the circuit is working with the ideal functionality, the solar subsystem was removed from the base station breadboard to a separate breadboard, so further integration and testing can commence. Also, using extra parts another LiPo charger circuit was created on a prototype board to scale down the size of the circuit and prepare for multiple torch testing as seen below. Currently, the assembly contains only the LiPo charger wired to where the ESP32 client should connect and the battery for the solar power to charge.

To prepare for full integration testing, the original ESP32-C3-Mini model used in testing was exchanged for a ESP32-WROVER model so it can collect capacitive data from the level sensor. The final prototype of the solar subsystem is displayed below with the main change being the replacement of the new ESP32 and removal of the voltage regulator circuit.

Micro-Controller Programming: Preliminary Sensor Testing

Since Phase 6, the objective for this phase was to continue making progress coding the ESP32 client and server. The team aimed to send data collected from the capacitive sensor made from copper tape back and forth between the client and server. A couple notable changes since Phase 6 includes implementing a new ESP32 dev kit into our design. For each of the individual torch (client ESP32), a ESP32-WROVER model will be used, so it can connect capacitive measurements. The ESP32-C3-Mini model used previously for both the client and the server will only be used in the future as the server due to the lack of capacitive sensing capabilities.

The major accomplishment for the code for this phase was getting a server and client to be able to fully connect and be able to send over data over the same network. The previous phase had shown just a server being set up with a phone being able to connect to the server. For this phase we were able to get a client (ESP32-WROVER) to also connect to the server and hook up a sensor to it and be able to transmit data read from the capacitive sensor. Since we have taken the approach of using a point-to-point Wi-Fi connection, we are sending over data by POST and GET requests.

Once the code was implemented to add capacitive sensing capabilities via the copper tape sensor, testing to discover the appropriate threshold voltage began. Using a metal bowl, some copper tape was applied to the outskirts of the bowl with a wire attached to the tape as seen in the picture below. The wire connected to the bowl was placed in Pin 4 of the ESP32, so that data values for capacitive sensing could be collected. The team simulated capacitive sensing on the client by placing water into the bowl. Simply by adding water the team observed little change in values. The next test was to place a finger in the bowl which showed a larger change. The team predicts that with a liquid of a larger viscosity we will be able to detect a large change in capacitance compared to water.

Individual Torch Integration and Testing

After simulating the solar system and the capacitive sensor individually, the next task was to integrate the two together so that we would see an individual torch working. Minor adjustments to the solar system breadboard were made in order to accommodate the new ESP32 client and to integrate capacitive sensing. The pictures below shown the building process and final results of the build:

(a) torch tank with capacitive sensing leads and power and ground wires

(b) full torch assembly with capacitive sensing torch tank and tubing

(c) new solar assembly attached to torch tank

(d) breadboard containing solar power circuit and ESP32 Client

(e) full torch head assembly containing all individual torch electronics

After the torch was fully assembled with the subsystem prototypes, the torch was taken outside to test on October 27th. The weather was partly cloudy but had adequate sun in the morning to test. Once placed in the grassy area between the James Gleason building and Booth Hall, we immediately saw the green LED on the LiPo charger light up signaling power was being generated from the solar panels. After several seconds the red LED turned on indicating the LiPo battery was charging. Several seconds after that, the red LED on the ESP32 was turned on. Both red LED were dim and flickered compare to when a constant voltage source was applied such as voltage from a computer when programming the ESP32. A picture of the lit LED are seen below. Thus, voltage measurements were taken using a multimeter at the output pins of the LiPo charger and the input pins on the ESP32. At both, a reading of approximately 3.0V was recorded, however, the reading was very unstable. Next a reading at the solar panel input leads were taken and record to be approximately 5V which was significantly higher. Reasoning for this dramatic difference may be attributed to the battery not being able to charge simultaneously with trying to power up the ESP32.

Next, testing to see if data could be transmitted to the server and read was conducted. Unfortunately, we could not do this wirelessly which was most likely due to the lack of a steady voltage. Further troubleshooting will occur in Phase 8. Instead, to ensure that the set up actually works we made a hard connection from the ESP32 client to the computer. A server was not used to receive the values, and instead, the capacitive sensing values were read from the connection between the computer and ESP32 client. Compared to the values during the bowl testing which range from 30-50, the values of capacitance were much smaller. Capacitive values sent from the server via the client are shown below with the corresponding source of capacitance as seen below in the table.

Possible reasoning behind the low values are hypothesized to be from the smaller tank sized used. During this test we noticed by even touching the pole of the ESP32 the capacitance would change which is a concern due to the small range of detected capacitances. For Phase 8, we will explore the display value capabilities in efforts to acquire a bigger range of value that will avoid falsely triggering the pump to refuel.

• Pre-read: P21389_IntegratedSystemBuild&Test_Preread (3).pdf
• Presentation: Phase VII_ Review.pdf

Here is an outline of tasks that we aim to accomplish in order to meet our objective:

• General
  • Create a schedule outline to test system with citronella oil
• Mechanical
  • Finish manufacturing a new torch body for testing purposes
  • Resume work and testing of tank refueling valve
• Electrical
  • Research/select a new LiPo Charger with a switching circuit for charging and discharging
  • Improve precision of reporting capacitive values to create bigger distinction between "high" and "low" levels of fuel
• Administrative
  • Seek approval for burning torch on campus

(three week plans here):