I went to Tacoma on the 29th and Chris and I worked a bit on the robot. We added a shelf extending off the back for the brake mount, shifting actuator, and DARPA boxes. After that we completely dismantled the robot, welded a floor on, and planned out how we will seal the electronics-side with sheet metal. We didn't have any more sheet metal and Chris's welder had run out of gas, so we left the Expeditor in Tacoma.

My dad and I went to the bank to get part 2B of the team application notarized. Basically it just says we aren't using government funding. My dad had to be the one to sign it because it must be the team leader, and the team leader has to be 21 years old or older.

For the last few days I've been working hard on the route planning software, and I've made several large programming breakthroughs.

I worked a little on the mapping software. Before today it was a separate program that was only a demonstration that it works, but now it has been incorperated into the autonomous ground vehicle software that actually drives the vehicle. I also made some changes so that the "map" created can be extended if the robot drive's "off the map".

The Futaba Radio controller has a power jack on it that is designed for charging it's 9.6V battery. I was planning on powering the new safety transmitter from this jack, so I bought a couple power plugs at RadioShack today. However, I discovered that the power jack is only connected to the controller's battery when the controller is turned off. I don't know why it is designed like this, except maybe so that the battery could be charged by a non-regulated battery charger without the possibility of damage to the circuit, or maybe the battery is supposed to be charged with 12V and this voltage would damage the circuit. I opened the controller and rewired it so that the jack is directly connected to the battery, so now I can have the radio on and power my transmitter from the jack at the same time. I'll just have to remember to keep the radio off while I'm recharging its battery.

I made an and-gate so that the new safety receiver and the old one must both be receiving their own signals, and then put the whole circuit board in the radio enclosure and bolted it back onto the robot. When I tested it, however, it only had a range of a few feet. Since I had a range of several hundred feet earlier I think this may be the effect of dead batteries. I'll know for sure later.

I finished soldering the new safety-receiver circuit, but I still need to connect it's output by an and gate to the output of the old safety circuit, so that the 75Mhz Futaba radio signal must be being received as well as the encoded 533Mhz signal for the robot to stay on.

I began soldering the safety-receiver circuit.

I improved the safety-transmitter circuit so that it transmits the 8-bit pattern about twice as fast, and then adjusted the receiver circuit so that it must receive the pattern more frequently for it's output to remain on. A new distance test showed that it can transmit over 400ft through walls. Later I soldered the transmitter circuit and put it on the radio transmitter.

I finished a circuit that transmits an 8-bit pattern approximately once a second, and another circuit that must receive this pattern at least once a second to keep a relay open. The transmitter circuit will be added to my remote control, and the relay will be connected so that it must be open for the engine to be on and for the brakes to be off.

I also got a reply from DARPA about my inquiry regarding the touch-screen monitor's remote control functions. They said that "It is unlikely that the monitor’s IR wireless communications capability that you described would violate the Grand Challenge 2005 rules as long as it is clear that the capability is not and can not be used."

I added a video of the first driverless test to the links page under the "Miscellaneous" category.

The touch-screen monitor came in the mail, and I installed the TouchKit software on both computers. The only question I have about permanently installing the monitor on the Expeditor is that it has built in remote control capabilities, and this might not fit the wireless communication requirements.

I just checked the rules and they say that "the emission or reception of communication signals is prohibited." The monitor would not be receiving or transmitting signals, but the rules also say "Any wireless systems used for vehicle movement or testing must be disconnected prior to the departure signal". I'll send DARPA an email. If necessary we can make the monitor removable for the actual race.

I've been experimenting with some RF transmitter/receiver ICs. I have the transmitter connected to an encoder IC and the receiver connected to a decoder IC, so that radio interference will not trick the receiver into thinking that the transmitter is on when it actually isn't. Although they say that they will work up to 400ft apart, today they only went one or two hundred feet. I'm going to connect the transmitter to the remote control and put the receiver on the robot. If the receiver stops receiving the signal, it will shut the engine off. Since the signal is encoded this should prevent radio interference from making the robot drive randomly and crash again.