## 2-25-2025 - 2-26-2025: Starting on Kicad schematic
<details><summary>Click to expand</summary>
2/25:
- We didn't do much. We worked more on the PCB schematic and used ltspice to simulate our lock
- We used LT spice to simulate what how our lock circuit could be set up to all.The resulting cirucit and graph are shown below.
The cirucit uses a bjt to limit current to the lock selectively. The green line on the graph shows how when we send the signal to the bjt the current being
flowing to 30mA then when we disconnected the signal to the bjt the current stopped flowing. Although 30mA isnt the exact Ampages we may want the behavior is what we want.
- We had our TA meeting and we showed our TA the start of our schematic. He told us we should keep traces in mind and that we should go to the the PCB design review on friday. I have to go home this week but my partners will attend
2/26:
- We learned we needed to redo out esp schematic design becuase there are different esps and we were not using the right footprint fo the r one we wanted to use.
- We are reconsidering heating because we dont know if we will have time to implement it and all the other component are more important to the functionality than heating.
- We order some the lock and the temperature.
</details>
## 3-2-2025 - 3-8-2025: Design Doc, started work for Breadboard demo
<details><summary>Click to expand</summary>
3/2:
- Druva sent the PCB design and it passed audit. Also started the design doc.
3/5:
- We finished the Design doc.
3/6:
- We went to the ece shop and bought a dev board for the breadboard demo next week (picture of layout below).
The lock, and fingerprint sensor, the temperature sensor arrived. We tried to install ardino on all three of our computers
but it didnt work for Dhruva and me so we are going to use Rohans computer.
Once we got arduino to work we tested wifi through our devboard using gpio 5 and it worked.
Then we connected the temp sensor to one of the gpios and checked to check that it was working and reading accurately.
At first it didnt read accurate but after ajusting the calibration factor a little we got more accurate readings. We werent
sure if it worked at first so we took it outside while it was a little cold and windy and we saw reasonable decrease in temperature, but it too a little time.
3/8:
- Dhruva got his arduino to work and made the code for the website
- We worked on the bjt ( [(tip120)](https://www.onsemi.com/pdf/datasheet/tip120-d.pdf), with [(current and voltage ratings)](https://www.st.com/content/ccc/resource/technical/document/datasheet/f9/ed/f5/44/26/b9/43/a4/CD00000911.pdf/files/CD00000911.pdf/jcr:content/translations/en.CD00000911.pdf)) lock cirucit with the devboard but we couldnt get it right reason.
So we used our own breadboard and played around with the circuit without the devboard and used 2 power sources in the lab for the 12v and 3.3v.
After changing resistors and trying to connect the the base, collector, and emmitor different ways we, with the help of another group who used a lock, drew the circuit on the
whiteboard to make sure we were wiring it right (drawing below). After doing this and confirming which pins were the base, collector, and emmitor we finally got it to work.
After that we slowly transfered the circuit back to the original breadboad with the devboard and it worked.
</details>
## 3-10-2025 - 3-12-2025: More breadboard demo prep, Demo, PCB order 2
<details><summary>Click to expand</summary>
3/10:
- We tried to wire up the fingerprint sensor to the devboard but
we couldn't connected it. We got it to light up so it was getting power from the esp but
for some reason it wasn't recognized by arduino. We kept trying it but we ended up breaking it by giving it too much voltage to the point where the lights wouldnt turn on again.
We then checked out a new fringerprint sensor from the lab but decided not test it before we figure out the problem.
- We tried to work on the weight sensor, but we were not getting a proper reading, we think it might be that the signal isnt beign amplified enough. We used the ina that came with the sensor but we might use the [hx711](https://cdn.sparkfun.com/datasheets/Sensors/ForceFlex/hx711_english.pdf) as the signal amplifier instead because there is more documentation using it.
- Wired keypad with [matrix scanning](https://cdn.sparkfun.com/assets/7/e/f/6/f/sparkfun_keypad.pdf) to the devboard.
I worked rather consistantly but sometimes wires come loose.
3/11:
- Breadboard demo day. Really early. We showed them the box locks the keypad works and that we have a website. Asked about swithcing to a button on the website
instead of the fingerprint sensor but that would reduce complexity, so we either find another way or make the fingerprint sensor work.
3/12:
- Whole aday was spent on pcb design, We dont think the first pcb will work because of the traces might be wrong because we used auto router,
so this time we manually routed everything.
</details>
## 3-25-2025 - 3-28-2025: Tested the Nichrome heating and the voltage subsytem on pcb order 2
<details><summary>Click to expand</summary>
3/25:
- Both pcb order 1 and 2 came. We forgot to give the parts to the machine shop.
- We tried the different fingerprint scanner but we had the same problem.
- We tried the Nichrome wire on the breadboard with just the devboard and a resistor just to see if it would get hot and it did.
We tried multiple different resistors.We then tried using the same ciruit setup as the lock with bjt so that we could selectively turn on heating but it would no loger heat up.
- We decided to try and replace fingerprint with RFID. We borrowed one from the lab.
3/27:
- Dhruva took the rfid home and got it working.
- We began soldering parts to our second order to test the voltage requlator with the esp using the lab equipment.
We measured the voltages using the multimeter and the correct voltages were not being outputted so we know our order 2 power subsystem is wrong.
3/28:
- We tested all our current parts on the devboard gpios one last time to check the gpios that work for each component.
- We got the wrong weight sensor because its too small, so we ordered a new one.
</details>
## 3-30-2025 - 4-6-2025: Tested the Nichrome heating and the voltage subsytem on pcb order 2
<details><summary>Click to expand</summary>
3/30:
- sent the 2 PCBs files, 1 with the esp chip and one witht he devboard just in case we dont get voltage regulation to work.
4/1:
- TA meeting today, we talked about changing to RFID instead of fingerprint.
We also grading for the final demo and we found out that its most important get the esp chip onto the board and be able to program it.
We also found out that it was ok to have tiny devboards like the hx711 or the ina for the weight sensor.
- We dropped off our paerts to the machine shop.
- We tested the heater with the same setup as the lock again and it wasn't getting noticeable warmer.
We used the multimeter and saw rhat the wire wasn't getting 12V.
