i know its tight but i use toner transfer 24 ist the thinest i can manage... i checked for short cuts: none. TDO is connected. dont know why its not in the layout (maybe an accidental undo before saving). yes i forgot VSS right, corrected now. still doesnt work. windows still says its not recognizing it :(
i also wanted to build this thing. i transfered this http://sa89a.net/ele/ub/circuitv4.png schematic to eagel and burned my PCB. i tried severel versions of the firmware but its not working for toffee :(
could you take a look at my files and let me know what might be wrong? thanks a lot in advance.
If the zeners in the schematics are wrong they are 3V6 in the actual board. Mistyping...
Well yes they are thick. But I use toner transfer method to make PCBs (no access to better methode) and 24 is the smallest I can manage with my printer. I already checked for short cuts with my multileter. I'm pretty sure there are non... but I will check again. I read somewhere USB is not specified to have the shielding grounded on the slave side. I might be wrong but I doubt its connected to the SDA stays high problem. But if you think so the iron is not far.
EDIT: Ok checked the traced again and found a shortcut between VCC and P1 which explains nearly all previous problems. SDA tied to high and failing at updating firmware (and maybe the heating as well)... now I'm a bit embarrassed. Sorry for bothering you about this.
About the temperature: well havent checked it yet but till now its havent been a problem again... well... maybe just because I didnt leave the LW in the port for a while... will check that again later.
Micronucleus sounds perfect!! :)
I²C: Ok I switched to plain C and its still not working neither with P1 nor with P2. I hoocked up a logic analyzer to it and it seems like SDA stays high all the time doesnt matter if P1 or P2. :(
I'm pretty happy to have my own LittleWire now working. Its getting recognized like a charm. But I noticed some things:
Its getting really hot. Is that normal? I used the original schematics from http://littlewire.cc/ but routed my own PCB. The chip is an Attiny85-PU20 so shouldnt it coap with the high frequencies?
Another thing is: the 16bit fboot.exe dosent work under 64bit environments. I was looking for a 32bit/64bit version and found one in this thread: http://www.mikrocontroller.net/topic/73196#698193 (I guess you need google translate).
But since the previous problem was solved another one arose. The update precedure doesnt work for toffee. Shouldnt I connect the GND wire as well (not only RX and TX)? Or is it supposed to be provided by the LittleWire USB connection? If yes: That is also problematic because my PC has just one 2.0 and one 3.0 USB port and they seem to be electrically isolated from each other.
I²C: Well it doesnt seem to work. I hooked a PCF8574 up to the LittleWire and 4K7 resistors between VCC and SCL/SDA (A0-A2=GND => addr=0x40). I modified the i2c_blinkM.cpp of the kehribar 1.1 version (attachement). Can someone confirm that or is just my problem?
Well thats it so far. For help I would be grateful...
