vedge

Thanks, but nogo in both cases. The core seems fine with another PIC ive swapped in. MIDI I/O and all. Secondly, the "broken" pic doesnt do an upload request like it once did upon bootup.

Yes i tried to upload J5_dout, which previously worked., but now it seems i cant upload anything. I dont have my hopes up. as there is no uplaod request ever in MIOS Studio's Input logger. Whats the best moment to upload manually? in the first 2secs? Ive tried that, with no avail.

Yeah, but im my situation, i dont know if my curretn MIOS projects warrant the time/effort to build a JDM. Maybe if i lose another :)

Hello I was happily developing a custom application with a SmashTV Core and PIC for a few evenings in a row (uploading new sysex files around 10 times an hour .. or more). When suddenly, at one point after an upload, 1)reboot 2)LCD shows MIOS 1.9 bla bla 3)LCD show random chars on the bottom row. Odd i think. trying to upload file again, same 1-2-3 results. Hum, then i tried to upload a known working app (J5_dout test)... same thing. After i tried everyhing, reloading MIOS 1.9c -> boot loader up to date. (yay i think) ... then dunno what happened but now it seems completely dead. I cant even send stuff to it (even in manual fashion). There is no OS or anything. Was i too heavy on the flashing? I have a spare PIC from a MIDIBOX SID that i can use - i swapped that PIC on the (now) empty core and i was able to re upload SID 1.7 on it no problem but im scared this could happen again. (maybe i was unlucky and got a faulty chip). But maybe not. + i dont want to to break my SID box. :) Anything i could do? ... It would seem dumb to pay shipping twice to get my PIC re flashed ... when i dont even know if thats going to help! I already have another PIC in the mail, but any pointers on what NOT to do? Or any last attempts to salvage the one i have? It doesnt send any sysex upon boot. Only a all too familliar black front row on the LCD.

Many thanks. Question #1 -> Sorted!

Ive no clue what the difference is. the 10 Mhz crystal in the typical core... is that a Fosc or a Tosc? how should I know, you tell me :) TK should spill the beans! not me. i dont know why/.whats the use of the external postcaler. its to drive different "servo" something, the word 'servo" only appear ONCE in the whole pdf. And its in that occasion... MBOX Moter Fader?

Only one or two hours before going to sleep ... aint that a good idea :)

But should I? The chip seems to work fine so far, and ive been running it for a few hours and it didnt melt :) I was just curious about that particular Spec sheets and its 50 mA input limit. (thats 50 mA lower than the SID and 150 lower than the PIC specs) I mean, they must write that for a reason other than "dont feed that 10A"! The other thing about the ohm law that confused me was because of my test with a multimeter. If i set my multimeter to check for voltage under this scenario: I naively tought that the voltage was a constant, and figured out, if i wanted 5 VCD, and 33 mA, then R = V/I R = 5/0.033 R = 150 Trying this J2+ ------ 150Ohm_rez ------ + terminal_of_multimeter J2- -------------------------- - terminal_of_multimeter I STILL get 5vcd, but a new 33 mA of measured current. (and the core PIC didnt reset when mesuring amperage:) Where as when i inserted the 150 ohm res in the actual circuit, powered it up and checked again with the same multimeter, the voltage was now 2.3 volts. Ok 5VCD is NOT a constant it seems. So all values are really interconnected in the ohm law. and nothing is constant if you change any value. but why the h___ does my multimeter trick me?

Ok this one is a tad bit harder :) I followed the MIDIBOX SID code to generate a fake clock from the PWM unit. The current SID's main.asm code generates a 1 Mhz clock out of a 10 Mhz Fosc. I want to do 3.5 Mhz out of a 10 Mhz Fosc (yes i could live with 4.0 or 3.3333). Now i know that the resolution might be too crapy to be usefull. after scratching my head for a while i think i managed to get the clock running at 2 Mhz, but the PIC manual is either very poorly writen, or i just dont get it (again). the basic calculations are something like this; unsigned char pr2 = 0x09; // PWM period unsigned int fosc = 10000000; // Oscillator frequency unsigned char tmr2 = 1; // TMR2 prescaler unsigned int duty_cycle =19; // PWM duty cycle double pwm_period; // PWM period double pwm_freq; // PWM frequency double duty_cycle_t; // PWM dutcy cycle time double duty_cycle_f; // PWM dutcy cycle frequency float resulation_bits; // PWM resolation bits // Necessary calculations pwm_period = (pr2 + 1) * 4 * (1.0 / fosc) * tmr2; pwm_freq = 1.0 / pwm_period; duty_cycle_t = duty_cycle * (1.0 / fosc) * tmr2; duty_cycle_f = 1.0 / duty_cycle_t; resulation_bits = log10 ((double)fosc / pwm_freq) / log10 (2.0); calulating pwm_freq from this code (and the settings given by TK in main.asm of SID gives 250000.00000000 and not 1 Mhz ... But theres a 1:10 "postscaler" setup in T2CON as well... im confused. In theory, using 10 Mhz Fosc, we could derive a 5 Mhz clock with 50/50 duty cycle right 1,0,1,0,(...),1,0,1? (theres prolly overhead and other factors i dont know about) Heres my current code: PR2 = 0x04; //was 0x09 T2CON = 0x24; CCP1CON = 0x0f; //11xx = PWM mode CCPR1L = 0x04; This seems to run at 2 MHz now (im not exactly sure, i can only trust the +1 octave change i get in the outputs of the sound chip i use) (sorry if this seems unclear, ive been programming all day at work, and i try to make this HW synth work at home in the evenings, where the brain is not 100% working .... yeah maybe i should try and relax instead) More later.... if you dont mind,

Hello First out of many questions. I dont get how to one is supposed to limit the current being fed to a certain pin of "something" without droping voltage getting to it. In a daughter board im making, I want to keep feeding off the main 7805 for +5vdc, but if i use a resistor to limit the current going to my pin, of course the voltage will drop, and i dont want that. For instance, with the current core desing, the +5vdc is fed to pin 32 of the PIC, and pin 25 of the 6581, fine, but both these chips do have spec sheets on which its said that they should only be fed a certain maximum current. 250 mA for the PIC, (PIC18FXX2 manual section 22.0), and 100 mA for the 6581 (http://stud1.tuwien.ac.at/~e9426444/sidtech3.html) Now call be total newbie in electronics (true), but i just dont get it. is that a power consumption? or a "feeding limit" .. why dont these chips fry if i have 500 mA input? Im working on a few secret projects to drive some other sound chips. Im a very good audio/MIDI/realtime programmer, but a total retard in electronics, and i just have soo much to learn. the CHIP docs say "Supply Voltage (VCC) | MIN 4.5 VDC | TYP 5.0VDC | MAX 5.5VDC" "ICC Supply Current | OUtputs Open |Typ 30 mA | Max 50 Ma Thanks in advance for my stupid questions. Hopefully this one is the stupidest...