BlackIce Mx & IceCore initial feedback

[Folknology]

Looking at the digilent led pmod it uses npn transitors to drive the leds (rather than fets), that effectively puts a 2k2 resistor down to ground through the transistor (B-E junction like a diode).

Gives this circuit:

+3v3 ->|-1k-2k2->|-Gnd

Which will weakly turn on IceCore blue/green leds and may look like a low signal to the Ice40 which will then turn on red/yellow leds

[Folknology]

Thing to remember here is MixMod 3 is compromised as P48-P55 are shared with SDCard (all pulled up) and L0,L1 (Pulled up through leds effectively). MX3 is last choice of MixMods, Use MX1 and 2 first choice then lower half of MX3 before higher half and only when not using SDCard, L0 and L1..

[Folknology]

One other bad thing to do generally with IceCore is drive Green and Blue LEDS and press buttons 1 and 2, but you probably already notice that!

[lawrie]

Without the Pmod in, I still have the problem that I can't detect a button press as both buttons cause button1 to record a press and slight taps on either button or elsewhere on the board record a button press.

[Folknology]

Without the Pmod in, I still have the problem that I can't detect a button press as both buttons cause button1 to record a press and slight taps on either button or elsewhere on the board record a button press.

The digilent led pmod will effectively pull those signals low..

[lawrie]

But I have removed that from the equation, and I still have all those problems.

[Folknology]

Ok please tell me what you see now the pmod is removed led state etc..

[lawrie]

Ok please tell me what you see now the pmod is removed led state etc..

That is what I just said:

Without the Pmod in, I still have the problem that I can't detect a button press as both buttons cause button1 to record a press and slight taps on either button or elsewhere on the board record a button press.

[lawrie]

Here for example is press button2, causing the blue and red leds to come on. It should not set the red led as that is button 1 state.

[Folknology]

OK I'm trying your Verilog here, either S1 or S2 activates the red permanently but I don't get the taps elsewhere on the board issue

[lawrie]

I am trying increasing the counter width in the debouncer to see if that helps. It looks as if it might.

It helps with the problem with light taps and taps elsewhere but not with button2 causing a button 1 press.

[Folknology]

Yup that Thats what I did , changed reg [15:0] PB_cnt to reg [20:0] PB_cnt and now it seems to work ok. That gives it a debounce of about 4ms which just does it for a mechanical switch YMMV

[lawrie]

But we still can't distinguish button 1 and button 2 presses.

[lawrie]

I am now trying to use the program to determine which pin number corresponds to which Pmod position, which was my original purpose for it. One button is sufficient for that.

What numbering scheme are you using for Pmods, so I can use the same terminology as you.

[Folknology]

What numbering scheme are you using for Pmods, so I can use the same terminology as you.

Haven't really thought about that yet, I think I used the PXX numbers from the BlackIceMx schematic for the PCF file (Notice P00-P07 are HDMI not pmod/mixmod pins)

[lawrie]

But that file called them all pmod ?, and it does not seem to be correct.

[Folknology]

Yup the grouping in the PCF file does not represent PMOD grouping I suspect

[lawrie]

This is what I get if I press button1 8 times, which should be PMOD[8].

It certainly doesn't seem to correspond in any way to the pcf file.

[Folknology]

P[X] represents the PX on BlackIceMx schematic but they are not correctly grouped into PMODs

[Folknology]

Just editing hold on