Patent Application
20140278842
1. Field
The present disclosure relates to temperature sensors and, more specifically, to systems and processes for collecting, encoding, and transmitting cook stove usage statistics using a temperature sensor.
2. Related Art
Traditional cook stoves release carbon dioxide (CO2) into the air, a major global warming gas. Traditional cook stoves also release Short Lived Climate Pollutants (SLCPs), such as black carbon, methane, and ozone. SLCPs have global warming potentials that are even larger than the potential of CO2. In addition to the climate impacts, SLCPs also have grave human impacts. The release of SLCPs into the air have caused over 2 million deaths, hundreds of millions of dollars in crop damages, the melting of glaciers in the Himalayas/Tibet region, and disruption of rainfall.
While improved cook stoves that significantly reduce emissions of CO2 and SLCPs have become available, there is little incentive for owners of traditional cook stoves to expend their limited financial resources to purchase the improved cook stoves. Providing financial incentives for the amount of usage in time of the cleaner burning improved cook stoves will facilitate the adoption of the improved cook stoves. However, there is no existing reliable and accurate method for capturing and tracking the usage of cook stoves in rural areas.
Therefore, a system and method for conveniently, reliably, and accurately capturing and tracking the usage of cook stoves are highly advantageous.
An apparatus and method for encoding a stove usage time is described. The apparatus comprises a circuit, a temperature switch, an input device, and an output device. The circuit comprises a processor and an internal timer. The temperature switch is communicatively linked to the circuit. The input device is electrically connected to the circuit and is configured to transmit a status request to the processor in response to receiving a user input. The internal timer is configured to increment an accumulated time value of the internal timer by a usage time value. The usage time value is based on a duration the temperature switch detects temperatures higher than the minimum threshold. The processor is configured to access the incremented accumulated time value of the internal timer and store the incremented accumulated time value in a memory of the circuit. The processor is further configured to read the incremented accumulated time value from the memory of the circuit, encode the incremented accumulated time value into an encoded value, and in response to receiving the status request from the input device, cause the output device to produce the encoded value.
The present application can be best understood by reference to the following description taken in conjunction with the accompanying drawing figures, in which like parts may be referred to by like numerals.
The following description sets forth numerous specific configurations, parameters, and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present invention, but is instead provided as a description of exemplary embodiments.
Disclosed in the present application are systems and processes for encoding stove cook usage times. In one example, a stove timer is used to capture the duration of time that a stove has been used. This duration information is encoded into an alphanumeric value that is displayed for the stove user. The stove user may transmit this information to a central server. At the central server, the encoded duration information is received and decoded. Based on the received encoded duration information, the central server can determine the overall duration of usage for the stove and/or the duration of usage for the stove since the previous time the central server received encoded duration information for the stove.
The minimum threshold temperature and the maximum threshold temperature are configured to be significantly higher than ambient temperatures. This helps to prevent the temperature switch 104 from incorrectly detecting that the stove 102 is in use when in fact the stove 102 is not in use. For example, the minimum threshold temperature may be 100 degrees Celsius and the maximum threshold temperature may be 65 degrees Celsius. Thus, sensor indicates the stove is in use when the temperature reaches above 100 degrees Celsius and then the sensor indicates the stove is not in use when the temperature drops below 65 degrees Celsius.
When the temperature switch 104 is in the first state, the temperature switch 104 transmits a first signal to the display device 106. The first signal is an “ON” signal indicating to the display device 106 that the stove is in use. When the temperature switch 104 is in the second state, the temperature switch 104 transmits a second signal to the display device 106. The second signal is an “OFF” signal indicating to the display device 106 that the stove is not in use. For example, the temperature switch 104 may achieve these two states by closing a wire circuit connected to the display device 106 when the temperature switch 104 is in the first state (ON) and opening the wire circuit connected to the display device 106 when the temperature switch 104 is in the second state (OFF). Thus, the first signal may be caused by a closed circuit in the temperature switch 104 and the second signal may be caused by an open circuit in the temperature switch 104.
The temperature switch 104 is communicatively connected to the display device 106. Preferably, the connection is by one or more wires, as this reduces complexity and cost. However, the connection between the temperature switch 104 and the display device 106 may also be through other means, such as wireless through the use of a personal area network or the like.
The display device 106 includes circuitry, an output device 108, and an input device 110. The circuitry of display device 106 is communicatively connected to the temperature switch 104. The circuitry is also electrically connected to the output device 108 and the input device 110. The circuitry is used to detect the state of the temperature switch 104. The circuitry may be, for example, an embedded computer chip or computer processor. The circuitry includes an internal timer that increments while the circuitry of the display device 106 detects that the temperature switch 104 is in the first state (ON). When the circuitry of the display device 106 detects that the temperature switch 104 is in the second state (OFF), the internal timer does not increment. Alternatively or in addition, the internal timer does not increment when the circuitry of the display device 106 detects that the temperature switch 104 is not in the first state. As the internal time increments, the value of the internal timer is repeatedly stored in memory. The memory may be in persistent memory, such as solid state memory, or in non-persistent memory, such as random access memory (RAM).
The output device 108 may be a visual display, a speaker, a line out, or the like. In the example of
The internal timer may be configured to be reset by the user of the stove timer. The internal timer also has a maximum accumulated time value, after which the internal timer will roll over and begin incrementing from zero again. This will not affect determining the amount of time that has lapsed.
The input device 110 may be a single button, a keyboard input device, a radio frequency receiver, or the like. A user may use the input device 110 to send a status request signal to the circuitry of display device 106. In the example of
The encoded value for each accumulated time value is different than the corresponding accumulated time value. Each encoded value can be converted into a single corresponding accumulated time value, and thus there is no ambiguity when an encoded value is decoded. An encoding technique is used that makes it difficult to convert the encoded value to the accumulated time value. For example, a decryption key may be required to convert the encoded value back into the accumulated time value. In one example, a cryptographic block cipher algorithm is used to transform the accumulated time value to the encoded value. In another example, a look up table is stored in the memory of the display device 106 for encoding the accumulated time value into the encoded value. The same look up table is available at a remote server for use to decode the encoded value into the accumulated time value.
Once the encoded value is displayed in output device 108, the user of the stove captures and transmits the encoded value to a remote server. Generally, the correlation between the accumulated time value and the encoded value is not obvious. This makes it difficult for a user to guess a valid encoded value to be transmitted to a remove server. The transmission of the encoded value may happen many different ways. In one example, a user types the numeric encoded value into a phone and transmits it to the remote server by using SMS. In another example, the user captures an image of the encoded value using the image sensor of a cellular phone and transmits the image to the remote server by using MMS, email, or another image transfer service. In yet another example, the user records an audio recording of the encoded value (which may consist of various tones of different frequencies) and transmits the audio file to the remote server.
In one exemplary embodiment, an internal timer of a stove timer has an initial accumulated time value of 305 minutes. The user of the stove presses a button on the stove timer which causes the stove timer to encode the accumulated time value of 305 minutes into an encoded value of 15662. The encoded value of 15662 is displayed on the LCD of the stove timer. The user reads this encoded value and sends a text message containing the encoded value of 15662 to a remote server. The remote server receives the encoded value of 15662 and converts the encoded value back into the accumulated time value of 305 minutes. Based on an identifier included in the text message, the phone number the text message originated from, or another identifier, the remote server stores the accumulated time value of 305 minutes in association with the user's profile on the remote server. The remote server may also store the date and/or time that the text message communication was received in association with the 305 minutes accumulated time value. Once the remote server receives the text message, the remote server transmits a confirmation to the server indicating a valid or invalid encoded value was received.
Subsequently, the user uses the stove for a duration of 25 minutes. During this 25 minutes of stove use, the temperature sensor of the stove timer detects that the temperature of the stove is above a minimum threshold and signals that the internal timer should increment. The internal timer continues to increment during the 25 minutes. After the user is finished cooking, the user turns the stove off. When the temperature detected by the temperature sensor drops below the maximum threshold, the temperature sensor signals that the internal timer should stop incrementing. The stove timer stores the accumulated time value of 305 minutes +25 minutes into memory as 330 minutes. The user then presses the button on the stove timer. In response, the stove timer encodes the 330 minutes accumulated time value into an encoded value of 91562. The encoded value of 91562 is displayed on the LCD of the stove timer. The user reads this encoded value and sends a text message containing the encoded value of 91562 to a remote server. The remote server receives the encoded value of 91562 and converts the encoded value back into the accumulated time value of 330 minutes. Based on the identifier, the remote server stores the accumulated time value of 330 minutes in association with the user's profile on the remote server. The date and/or time that the text message communication was received may also be stored in association with the 330 minutes accumulated time value. Using the 305 minutes accumulated time value previously stored and the 330 minutes accumulated time value currently stored, the remote server can calculate the amount of time that the stove has been used since the previous text message was received. In this case, the store has been used for 25 minutes. Once the remote server receives the text message, the remote server transmits a confirmation to the server indicating a valid or invalid encoded value was received.
By encoding the accumulated time value into an encoded value, incorrect or purposefully falsified reports of cooking time are minimized. A checksum digit is included in the encoded value to indicate whether the number was correctly entered and transmitted to the remote server. If an invalid encoded value is received, the remote server can prompt the user to resubmit a valid encoded value. The server may also transmit reminder messages to the user via SMS or other communications requesting that the user submit the encoded value displayed on the stove timer.
One technique for registering a stove counter or stove with an attached stove counter is to transmit an SMS message to the remote server for registration. The SMS may include a unique identifier of the stove or stove counter.
In one exemplary embodiment, an individual can use his or her mobile phone at the point of sale of a stove with a stove counter to register the stove. The user can send an SMS message to the remote server in the form of: “register <stove serial number>.” The remote server transmits a conformation SMS back to the user. The confirmation may say, for example: “Thank you for registering with Surya Stove. To submit cooking duration, please send an SMS with the number on the display.”
One way to minimize fraud is to limit the number of phones (or phone numbers) that may be associated with one stove. For example, the remote server may only allow a one-to-one relationship between phones (or phone numbers) and stove serial numbers.
Payment for using the stove encourages individuals to purchase the stove and use the cleaner burning stove in place of older conventional cook stoves. When the system determines that a user has used a stove for a duration of time, the user is credited for the time the stove was used. The credit may be issued in the form of cash, check, credit towards an existing bill (such as a phone bill), or the like.
In one exemplary embodiment, two temperature sensors (or temperature switches) may be used. Accordingly, the system is configured to receive temperature readings and/or ON/OFF signals from both temperature sensors. A first temperature sensor is used in association with the minimum temperature value. When the system determines that the first temperature sensor detects temperatures above the minimum temperature value, the timer begins to run. The second temperature sensor is used in association with the maximum temperature value. When the system determines that the second temperature sensor detects temperatures below the maximum temperature value, the timer stops running. The maximum temperature value may be less than the minimum temperature value. One of ordinary skill in the art will appreciate that other aspects described may be incorporated into this embodiment and that aspects of this embodiment may be incorporated into other described configurations.
In another exemplary embodiment, two temperature sensors (or temperature switches) may be used. Accordingly, the system is configured to receive temperature readings and/or ON/OFF signals from both temperature sensors. The first temperature sensor may be a thermistor that sends an analog or digital signal to the device circuitry indicative of the detected temperature. The system accesses this temperature reading and determines whether to power on additional portions of the system (or power off) by comparing the temperature reading to a first set of stored minimum and/or maximum temperature values. The second temperature sensor is used to determine when to start and stop the timer that tracks the duration of stove use. When the temperature reading is above a second minimum temperature value it will start counting. When the temperature value goes below a second maximum temperature value it will stop counting. The second maximum temperature value may be less than the second minimum temperature value. One of ordinary skill in the art will appreciate that other aspects described may be incorporated into this embodiment and that aspects of this embodiment may be incorporated into other described configurations.
At block 202, the stove timer system boots up. At block 204, the system is placed into a high-power mode. When in the high-power mode, all or more aspects of the system are functional, but at the cost of higher power and/or battery usage. At block 206, the system accesses an accumulated time value that was previously stored in memory. At block 208, the system checks the state of the temperature switch. If the temperature switch is OFF, indicating that the temperature switch is not detecting a temperature above a threshold, the system moves to block 210. If the temperature switch is ON, indicating that the temperature switch is detecting a temperature above the threshold, the system moves to block 216.
At block 210, the system checks the state of the input button. If the input button status is ON, it is indicative that the button has been depressed, and the system progresses to block 212. At block 212, the system encodes the accumulated time value accessed at block 206 into an encoded value. The encoded value is displayed on an LCD at block 214. The system then returns to block 208 to check the state of the temperature switch. If the input button status is OFF, it is indicative that the button has not been depressed, and the system progresses to block 226. At block 226, the system enters a low-power mode. The low-power mode shuts off part of the electronics of the system in order to conserve power or battery. This comes at the cost of reduced functionality. The system may be configured to periodically come out of low-power mode to check for inputs or temperature switch states.
At block 216, the system starts an internal timer. The timer may progress starting from the accessed accumulated time value or may progress from 0. At block 218, an indicator informs the user that the internal timer is running. The indicator may be, for example a light on an LED or LCD. At block 220, the system checks the state of the temperature switch. If the temperature switch is ON, the timer continues to run and the system returns to block 218. If the temperature switch is OFF, the system stops the internal timer at block 222. If the timer had progressed from a value of 0, the timer value is added to the accumulated time value of block 206. At block 224, the updated accumulated time value is stored in memory. At block 226, the system enters a low-power mode. The system may be configured to periodically come out of low power mode to check for inputs or temperature switch states.
In one example, the computing system 300 may include one or more processors and instructions stored in a non-transitory computer-readable storage medium, such as a memory or storage device, that when executed by the one or more processors, perform the processes for encoding a stove usage time as discussed above. In the context of the embodiments described herein, a “non-transitory computer readable-storage medium” can be any medium that can contain or store the program for use by or in connection with the instruction execution system, apparatus, or device. The non-transitory computer-readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable optical disc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flash memory such as compact flash cards, secured digital cards, USB memory devices, memory sticks, and the like.
At least some values based on the results of the above-described processes can be saved for subsequent use, such as accumulated time values or encoded values. Additionally, a non-transitory computer-readable storage medium can be used to store (e.g., tangibly embody) one or more computer programs for performing any one of the above-described processes by means of a computer. The computer program may be written, for example, in a general-purpose programming language (e.g., Pascal, C, C++) or some specialized application-specific language.
Although certain exemplary embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible to the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. For example, aspects of embodiments disclosed above can be combined in other combinations to form additional embodiments. Accordingly, all such modifications are intended to be included within the scope of this invention.
