The used chips .
The microcontroller itself offers a lot of possibilities , but not everything we needed was available . That is why we had to use some other components as well and we included a few other chips in our network .
Following components were used .:
Datasheets of these components can be found on following addresses :
Now let us look in detail what we used these extra components for .
LM741 .
The LM741 is used as an OPAMP . We simply used this component as a comparator and as a buffer in the network that we created to convert the signal we get from the whirl current collector , which provides the RPM signal , into a block wave .
MAX1270 .
The MAX1270 and the according network on a waffle
The signal we get from the torque sensor is an analog voltage signal . The microcontroller on the other hand needs digital input signals . Consequently , an analog to digital converter is required . On the microcontroller , an 8-bit ADC is already included . Unfortunately , 8 bits aren’t enough for our application . The torque can mount up to 40,71 Nm . If we want a resolution of 2 numbers after the comma , we need to be able to handle 4071 different values .
With an 8-bit ADC , we can handle 28 = 256 different values .
With a 12-bit ADC , such as the MAX1270 , on the other hand , we can handle 212 = 4096 different values . This is enough for our application .
CD4094BC .
The CD4094BC and the according network on a waffle
Once the incoming signals have been processed in the microcontroller , the outputs have to be displayed on the display . These outputs are the torque , the standard deviation on the torque and the number of revolutions . All these signals can again mount up to 12-bit signals . The microcontroller can only handle 8-bit signals , thus another chip was needed to solve this problem . We found the solution in the CD4094BC . This is a device that can serially shift 8 bits . By putting 2 of these chips in cascade , we were able to serially send the 12-bit data that we are working with , to the display .