Apparatus and method for accurate barcode scanning using dynamic timing feedback
An apparatus and method are described for accurately reading barcodes. For example, one embodiment of an apparatus comprises: a sensor to detect transitions between bars on a barcode having bars with N different widths as the barcode passes by the sensor; a timer to associate a time value with each of the transitions; a delta calculation module to determine a current delta value for a current bar; a bar identification module to compare the current delta value with N delta values stored in a memory, each of the N delta values associated with a different one of N different bar widths, the bar identification module to identify the current bar as being one of the N widths based on a difference between the current delta value and each of the N delta values, the bar identification module to update the memory to include the current delta value as a representative value for the one of the N widths which the current bar is determined to be; and a code translation module to receive a sequence of detected bar widths from the bar identification module and responsively translate the sequence of detected bars into a code.
1. An apparatus comprising:
a sensor to detect transitions between bars on a barcode having bars with N different widths as the barcode passes by the sensor;
a timer to associate a time value with each of the transitions;
a delta calculation module to determine a current delta value for a current bar;
a memory to store N delta values;
a bar identification module to compare the current delta value with one or more of the N delta values stored in the memory, each of the N delta values associated with a different one of N different bar widths, the bar identification module to identify the current bar as being one of the N widths based on a difference between the current delta value and each of the N delta values,
the bar identification module to update the memory to include the current delta value as a representative value for the one of the N widths which the current bar is determined to be, the current delta value replacing a prior delta value as the representative value for the one of the N widths, the bar identification module to use the current delta value to compare to subsequent delta values read from the same barcode as the current delta value; and
a code translation module to receive a sequence of detected bar widths from the bar identification module and responsively translate the sequence of detected bars into a code.
2. The apparatus as in claim 1 wherein the delta calculation module determines the current value by taking the difference between a first time at a transition point between the current bar and a next bar and a second time at a transition point between a previous bar and the current bar.
3. The apparatus as in claim 1 wherein the bar identification module identifies the current bar as being one of the N different widths by choosing the smallest difference between the current delta value and the delta values of each of the N different widths.
4. The apparatus as in claim 3 wherein N=2 and the bar width comprise narrow bars and wide bars.
5. The apparatus as in claim 4 wherein the barcode comprises a Code39 barcode.
6. The apparatus as in claim 3 wherein the barcode comprises a first set of N bars each having a different one of the N widths and positioned in a known order, wherein the delta calculation module is to determine initial delta values for each of the N bars using the known order.
7. The apparatus as in claim 6 wherein the delta calculation module is to initially compare a current delta value of a current bar with the initial delta values for each of the N bars.
8. The apparatus as in claim 1 further comprising:
a hub communicatively coupled to the code translation module, the hub having a first communication interface to communicatively couple the hub to a cloud service over the Internet, the hub to responsively transmit the code over the Internet to the cloud service.
9. The apparatus as in claim 8 wherein the hub comprises a second communication interface to establish local wireless connections with a plurality of devices, wherein the barcode is associated with a new device being communicatively coupled to the hub, the hub registering and/or pairing the device using the code provided by the code translation module.
10. The apparatus as in claim 9 wherein the code comprises a key associated with the device and usable for encrypting communication or generating digital signatures when communicating with the device.
11. A method comprising:
detecting transitions between bars on a barcode having bars with N different widths as the barcode passes by the sensor;
associating a time value with each of the transitions;
determining a current delta value for a current bar;
storing N delta values in a memory;
comparing the current delta value with one or more of the N delta values stored in the memory, each of the N delta values associated with a different one of N different bar widths;
identifying the current bar as being one of the N widths based on a difference between the current delta value and each of the N delta values;
updating a memory to include the current delta value as a representative value for the one of the N widths which the current bar is determined to be, the current delta value replacing a prior delta value as the representative value for the one of the N widths;
using the current delta value to compare to subsequent delta values read from the same barcode as the current delta value; and
receiving a sequence of detected bar widths; and
responsively translating the sequence of detected bars into a code.
12. The method as in claim 11 wherein the current value is determined by taking the difference between a first time at a transition point between the current bar and a next bar and a second time at a transition point between a previous bar and the current bar.
13. The method as in claim 11 wherein the current bar is identified as being one of the N different widths by choosing the smallest difference between the current delta value and the delta values of each of the N different widths.
14. The method as in claim 13 wherein N=2 and the bar width comprise narrow bars and wide bars.
15. The method as in claim 14 wherein the barcode comprises a Code39 barcode.
16. The method as in claim 13 wherein the barcode comprises a first set of N bars each having a different one of the N widths and positioned in a known order, wherein initial delta values are determined for each of the N bars using the known order.
17. The method as in claim 16 wherein a current delta value of a current bar is initially compared with the initial delta values for each of the N bars.
18. The method as in claim 11 further comprising:
providing the code to a hub, the hub having a first communication interface to communicatively couple the hub to a cloud service over the Internet, the hub to responsively transmit the code over the Internet to the cloud service.
19. The method as in claim 18 wherein the hub comprises a second communication interface to establish local wireless connections with a plurality of devices, wherein the barcode is associated with a new device being communicatively coupled to the hub, the hub registering and/or pairing the device using the code provided by the code translation module.
20. The method as in claim 19 wherein the code comprises a key associated with the device and usable for encrypting communication or generating digital signatures when communicating with the device.