so i decided to create the wired bus network. click the photo above to watch a video of it 67% working. at this point, i am able to blink all three LEDs at the onset of every command however node 2 is not responding (blinking or communicating back) in the way nodes 0, and 1 are (and it is ironically one of the boards with the prettiest traces.) i am in the process of troubleshooting that.
i began by designing the boards in Eagle, and then exporting as a "monochrome image" png at 600 dpi. i started with the bridge board and then realized it was really easy to create the node by simpy going to the schematic, deleting the ftdi connector and then connecting the traces from the microcontroller to the txrx 4-pin header.
click here for the hello.45.bus.bridge schematic
click here for the hello.45.bus.bridge board
click here for the hello.45.bus.node schematic
click here for the hello.45.bus.node board
click here for the traces
i milled and stuffed boards and tested each with a mutlimeter. the first board that was milled had alot of burrs and so i changed the endmill, and got really nice traces on the second and third boards. for the first board i tested all the traces before i began to stuff, and although it wasn't as pretty as the rest, everything checked out.
this was the first time successfully programming 3 boards with no problem with my FabISP in a matter of a few minutes. well...i almost used a 4-pin head power source because i thought how to get power to the nodes that are not the bridge, and just before i was going to fry my boards, a fellow fabber reminded me that there is no regulators on my boards and i'd be bringing in 9v instead of 5v... he suggested that i leave the bridge plugged in and connected to both nodes for power, but to switch programmer to nodes 1, and 2 when programming.
i changed the c code to make the blinks longer by changing led-delay to half a second, and then i changed it from one LED blink to three blinks when nodes are addressed in the main loop by adding 2 additional delay and flash sequences.
for programming: i connected the ftdi cable to the bridge and by ribbon cable to the FabISP. i saved the c file and makefile on the desktop, and loaded it as it was onto the bridge.
$ make -f hello.bus.45.make
$ sudo make -f hello.bus.45.make program-usbtiny
i then connected node 1 to the bridge with ribbon cable, disconnected the FabISP from the bridge and reconnected to node 1, then went to the c file and renamed the node id, as "1" and programmed it. i repeated the same for node 2. at first, all 3 nodes indicated being successfully programmed in the terminal, however, as of now only nodes 0 and 1 are fully functional.
***revisit***
i revisted this another day with the mental outlook of "i must be able to use my logic to find what is wrong with node 2."
what i know to be true about node 2:
1. the LED works because it flashes at the beginning of each command
2. the chip is programmed because avrdude tells me so.
3. its exactly the same layout + better traces than node 1 which works.
4. the program works because its on nodes 0 and 1.
something is screwy with the rx/tx portion of this. i rechecked with multimeter and although it checked out, i decided to remove the 4-pin header and attiny45 and replace those components with 2 new ones and resolder... and... it works!!! click the photo below for video of 100% functionality.
