54 M help

[Robot]

Can you please post the info to get 54m working , the old thread was deleted

- We need solder points for the consoles (where the clk wire goes)
- What parts are needed
- And how to connect the parts

Thx

[Emanuel]

Here is the setup I use:



You must link the OSC_IN and OSC_54 to make the Magic3 work and you must temporary disconnect them when you program the chip in-system.

Function of the hfe factor of the BFR transistor (can be any of BFR90, BFR91, BFR92), you may want to change the value of the 15K resistor in order to obtain the best performance. That is, the oscillations must be symmetrical (50% fill factor). This can be easily measured if you take a multimeter and put it between ground and pin 26 (osc out - this is what the SX28AC sees as oscillating frequency). You should have half of the supply voltage (2.50 V if you are using 5.00 V as Vcc). If you have a voltage error more than 0.2 V then you must change the 15K resistor with a higher or lower value and measure again. If the voltage on pin 26 is either 0.00V or 5.00 V then the oscillator is not working at all.

[bobthemoule]

Be very careful when you solder the BFR transistor. The best way to do it is to let your iron get hot, then UNPLUG IT FROM SECTOR, and solder the BFR while it's still hot. Otherwise you'll fried it.

[bobthemoule]

Emanuel : Which software did you use to draw such schematics ?

[Emanuel]

Schematic drawn with Eagle PCB 4.03
http://www.cadsoftusa.com/

[espi12]

I've done everything as you said, used shielded cable and I got 2.6V at OSC_OUT.
But it worked one time but no more! The ps2 makes random things, some times the cd doesn't move others the laser makes strange noise... I'm getting crazy.
I've tried with different values of resistor but no way...
Any suggestion, please?

The installation is OK, belive me!

[Emanuel]

I've encountered some instability problems on V4 systems (probably because the amplitude of the signal is twice greater than at the V5-V8). The sollution is to put a 10K resistor in front of the C2 capacitor and if it doesn't work, try to replace the 15K resistor with another one in order to have 2.8 ~ 2.9 V at pin 26. Also you must know that this voltage changes with temperature.
The wire that carries the clock signal must be as short as possible. Shielding it is not the best idea. A more effective one is to put a wire in spiral around it and link that wire to ground.
Some versions of ICE code (especially the most recent) stop the internal oscillator of the SC28AC, so that you won't get any signal at pin 28. Of course, there will be signal at pin 29.