courier project

[andy3]

Okay I'll try this again, after talking with Mike he recommended the Finder project as a place to start with this project I have in mind. However looking at the base tracker project forums, it looks like there is so much work that has been done (like having a PCB made) I might go back there.

The idea is to use the tracker as part of an automated courier. The other part being a toy blimp for starters. The idea would be do get things from point a to point b faster and cheaper than other means. For starters the payload would have to be small (e.g. just the tracker device) but who knows. I hope it may become an actual product someday. Anyone interested please let me know!

[Mike]

I suggest you start with a remote controlled toy car. The finder could be expanded to control one. You would have it step automatically through the list of saved locations, and use the left/right directions to control the steering. You need some kind of obstacle detector and code to support it.

Three-dimensional motion is a lot harder especially in the wind.

[andy3]

okay sounds good. I think I'll be lucky just to get the finder working!

[andy3]

Mike, I've prepared a list of parts that I will need:

AARLOGIC GPS 3A
ATMEGA88 or larger, a three-digit, common cathode LED display (Mouser BC56-11EWA or BC56-12GWA)
3 2N2222 transistors
1 2TX753 transistor
4 3.3K Resistors
2 220 ohm resistors
1 0.1 microfarad capacitor
1 3.3-3.6V battery
2 pushbuttons (find and save)

I noticed that you specify the AarLogic GPS 3A in the specs. After doing some research I noticed that Round Solutions is in the UK (quite far) and the module costs 279 Euros which according to my currency calculator is $409 which is a little pricey it seems like. Is it possible to substitute the 340-V23993-A1035D Vincotech GPS receiver module mentioned in the tracker project? If someone has brought this up before I appologize. Just want to make sure.

[Mike]

That price is for a starter kit including a lot of stuff you don't need. The module alone is under $50, although shipping will probably be expensive.

The A1035 will work fine. You do need to use a 3.3 volt regulator (just like in the tracker) for the Vincotech. Also change the BAUD_DIVISOR from 9600 to 4800. Just comment out the 9600 one and uncomment the 4800 one. Use the standby power diode as shown in the tracker.

I will help you debug the finder. In trade for some extra parts I will even build it for you. If I built it on a breadboard (i.e. not going for tiny size) it would be a one-sitting project. Let me know.

Mike

[andy3]

Thanks! Here's my actual mouser shopping cart. One mistake, the transistor was ZTX753 not 2TX753:

1
Mouser #: 556-ATMEGA88V10MU
Mfr. #: ATMEGA88V-10MU
Desc.: Microcontrollers - RISC 8kB Flash 0.5kB EEPROM 23 I/O Pins

2
Mouser #: 642-MHPS2283
Mfr. #: MHPS2283
Desc.: Key Switches 8.5mmDPDT PUSH PUSH

1
Mouser #: 140-50V5-104Z-RC
Mfr. #: 140-50V5-104Z-RC
Desc.: Ceramic Disc Capacitors 50V .1uF Y5V +80%/-20% Tol

2
Mouser #: 71-CMF55220R00FHEK
Mfr. #: CMF55220R00FHEK
Desc.: 1/4WATT Metal Film Resistors 1/4watt 220ohms 1%

4
Mouser #: 660-MF1/4DCT52R3301F
Mfr. #: MF1/4DCT52R3301F
Desc.: 1/4Watt Metal Film Resistors 1/4 WATT 3.3K OHM 1%

1
Mouser #: 522-ZTX753
Mfr. #: ZTX753
Desc.: Transistors PNP Super E-Line

3
Mouser #: 610-2N2222
Mfr. #: 2N2222
Desc.: Small Signal Transistors NPN Silicon

1
Mouser #: 604-BC5612GWA
Mfr. #: BC56-12GWA
Desc.: LED Displays GREEN DIFFUSED 3 DIGIT

1
Mouser #: 340-V23993-A1035D
Mfr. #: V23993-A1035D
Desc.: GPS Modules GPS Receiver Module w/Smart Ant. (SiRF)

[Mike]

You are about to order surface mount microcontrollers, good luck with those.
You want this one:
556-ATMEGA88-20PU
or
556-ATMEGA328P-PU

[andy3]

thanks i figured there was at least one part i messed up on!! no biggie thank you Mike!

[andy3]

I just got my first shipment today. The first thing I noticed is that the interface on the GPS unit is tiny! I got a couple extra components at Radio Shack to round out the project including a little breadboard and some 24 guage solid core. The 24 guage seems about perfect for the GPS.

[andy3]

After reading the schematic in more detail I see that I need eight 220 ohm resistors. Probably need some thinner wire too. Would be nice.