Code for the lab can be found here.
P H Y S I C A L C O M P U T I N G
j o u r n a l o f a l y s s a l e e s
Both the serial output and talking to processing components of this week's lab went smoothly. The answers to the questions posed in the lab are as follows : The reason that 48 is added to the value of the digital input is to convert the input into the corresponding ascii values. For example 48 + 0 = 48 which is ascii for 0. Likewise 48 + 1 = 49 which is ascii for 1. In ascii, 0 and 1 correspond to NUL and SOH. The reason the pot output is divided by 4 is that the original range of the pot is 0 to 1023. Dividing by 4 yields 256 values. 256 = 2^8 which is the max number of values which can be stored in a Byte. The first picture below is the layout of the breadboard for the lab. The second picture is demonstrating the use of a LED to test whether serial output is being sent.
I absolutely loved the reading this week 'The Bandwidth of Consciousness." As the author states, despite the large volume of sensory information flooding our brain it is humbling to realize that we are limited to consciously processing one piece of information at a time at the very slow rate of 40 bits/sec. This fact suggests that humans are amazing adept at classifying information into broad categories and processing patterns. In fact, the conscious processing of information chart presented on page 138 corroborates this statement. Humans can only count objects at the rate of 3 bits/sec, while they can read at 45 bits/sec. Reading involves a huge amount of interpolation and pattern recongition. When reading, a person does not consciously process every letter. In fact a study was conducted in which participants were asked to read a page of text where the centers of all the words were scrambled (word length remained the same and first/last letter remained in tact). Most partcipants could read the text with full comprehension - suggesting that human interpolate the information in the centers of word.
Final version of project can be found here.