The following story was submitted by Mike Karlesky, of Grand Valley State University.
Here is a team picture of the Grand Valley State University Electric RaceTeam. We compete in the Solar Splash which is an annual, inter-collegiate, solar/electric boat competition. Splash is usually held in Milwaukee on an artificial bay on Lake Michigan at the Meyer Festival grounds.
The two boats pictured are Loki and Proteus (Loki is on top). The two awards being held are 2nd place for educational display and the award for best electrical design. Proteus finished 7th out of 15. Loki was raced for the first time this year and finished 14th for a number of reasons. The team has placed as high as 2nd in the past.
We use the RPC-330 as the central component of a data acquisition system. It measures certain system values that are important for making race decisions during the endurance competition and analyzing test and competition performance.
In order to complete as many laps as possible within two hours, we must know how much energy we are consuming and how much we are taking in. If we go too fast, we drain our batteries beyond what the solar panels can replenish and will not be able to complete the race. If we go too slowly, we save energy but do not complete as many laps as possible. So, it is necessary to measure the voltage and current levels involved with the batteries, solar panels, and motors. Additionally, it is helpful to know our speed and the RPM of the drive shaft.
We filter and amplify signals read from the system and feed them into the RPC-330’s A/D channels. Speed over water is difficult to measure, so we use one of the serial ports to communicate with a GPS unit that measures our speed for us. The RPC-330 is then programmed to process all of this data and assemble it into a string of text. This string is sent via the second serial port to a packet radio modem which then broadcasts the data by way of a small radio unit. On shore, the data is then processed, displayed, and archived on a PC.
The RPC-330 is an exceptional piece of hardware. Each time we needed a particular feature, we would open the manual to discover that it was already there. The ease of programming made development time short and trouble shooting simple. Because the program is stored onboard the unit, it was quite straightforward to call up the program and make modifications. The RPC-330’s large amount of RAM, two serial ports, 8 A/D channels, display port, and digital ports and IRQ lines made it a perfect fit for our application.