Our client who had a restaurant in NY and served Italian food requested us to design a customized pasta cooker. Based on the favor of his customers and his longtime experience in working with different existing pasta cookers, he set a number of requirements for the new cooker.
1. As the device is plugged into the 110Vac inlet, the water in the tank is warmed up to 70°C
2. The water level in the tank and the jag is monitored and alarmed as it goes under a critical level.
3. Valves and water pump are supplied by the 12Vdc power supply.
4. Draining the water in the jag is controlled by a level sensor. But spraying salt liquid into the jag is by time counter in the program.
5. Water temperature in the jag is kept always around 100°C while the machine is working and the thermostat is just for safety. Water temperature in the tank is 65 to 75°C controlled by the thermostat. It is just a pre-warming up aimed at reducing the cooking time.
6. The cooking cycle is started just when the pallet is inside the device and the jag is seated in its place. This is controlled by magnetic safety switches.
7. Ultimately, the cooking of pasta be done in 3 minutes.
1. Finding the best cooking pattern for the product
2. Making a robust while cost-effective product
Based on the given requirements, a solution was followed that included the above requirements and had the followed 3 cooking modes. Each mode had its own procedures. Also, a timetable was created to include different cooking options.
Among the existing kinds of pasta in the market, some of the pastas that were requested by the client included Maggi pasta and Ramen (a Japanese food made with noodles)
1. Main mode
a. Water tank and liquid salt container are filled previously.
b. When the device is plugged to the main power (220v/50Hz power), the level sensor of the tank will check the level and if it is inside acceptable limit, the tank heater starts to warm the water inside the tank. The temperature is controlled by a thermostat and kept between 65 to 75°C.
c. The user pulls the pallet back and puts pasta inside the jag and push pallet back to the device.
d. The safety switches of “jag seat” and “pallet location” send a signal and let the machine is ready to start the operation. LCD displays “Machine is ready”.
e. The user pushes the “start” button.
f. The machine starts the default program as follow.
g. The “Hot water valve” turns on and at the same time the water pump starts to pump water from the tank to the jag and jag heater turns on to warm water up to 100°C. The water level is monitored by a level sensor inside the jag.
h. When the water level reached its limit, the “salt valve” turns on and “hot water valve” turns off. And after 5 seconds the salt valve turns off.
i. Stirring motor starts to turn the metal basket inside the jag. And a timer counts down the cooking time for 3.5 minutes. The time is displayed on the LCD.
j. As the timer reaches the zero, the heater turns off and “drain valve” turns on to drain liquid from the jag and at the same time, “Hot water” valve and water pump turn on to wash pasta inside the jag, for 10 seconds.
k. “hot water valve” and the water pump turns off and after a while, the drain valve turns off too.
l. An alarm announces the end of the cooking operation and LCD displays:” the pasta is ready”.
m. The user pulls the pallet off the device and takes the basket off the jag to serve the pasta.
2. Selecting other modes
a. time select: user can change the time of cooking by “up” and “down” buttons and register it by pressing the “start” button once.
b. wash mode: “water pump” and “stirring motor” turn on for one minute then “exhaust valve” turns on the level sensor senses the water is completely exhausted and then “exhaust valve” turns off and this will repeat triple times and then “water pump” and “stirring motor” turn off.
3. Main components
a. For the core processor an ATMEGA328P-AU (Arduino Nano) was selected. This processor was used to control the main functions of the cooker such as the followings:
i. Jag Safety switch
ii. Pallet safety switches
iii. Tank Water level sensor
iv. Jag water level sensor
v. Thermistor for tank temperature
vi. Thermistor for jag temperature
vii. Exhaust valve
viii. Water pump
ix. Stirring motor
x. The LCD display is I2c
b. Safety switches: (59020 Miniature Firecracker Reed Sensor + 57020 Actuator)
c. Thermistor: (PT100 Platinum Resistance Temperature Detector 22810 “StikonTM”)
d. Level sensors: (Madison liquid sensing technologies model: ML5555)
e. LCD: TC2004A-01
The project took about 9 months to get successfully finished and delivered to the client. The main challenge was to make sure that the cooking pattern was what the client had requested; therefore, it was actually tested by the client before the final prototype was made.