5TH "Test" program on FV-1 chip solution? (will this work?)

[PoisonNoises]

No. The DPDT is wired to instantly switch to Internal then back to External when you flip the switch.

This triggers a reload of the current program from the newly selected EEPROM.

So my test board finally came in, and I'm running into some issues. It seems that when I turn the rotary switch it does in fact recognize that it needs to switch EEPROMs. However 50 percent of the time it can't seem to pull any info from the chip. This again can be remedied by switching through the banks to trigger it and make it read the correct chip. However, when it does work it seems to swap EEPROMs without having to do so. I feel like I'm really close on this one!

 

[TubeGuy]

It looks like you are missing the I2C pull-up resistors on the SDA & SCL signals. This would make the I2C bus act strange and might be the issue. Add a couple resistors and see if that solves it.

 

[PoisonNoises]

It looks like you are missing the I2C pull-up resistors on the SDA & SCL signals. This would make the I2C bus act strange and might be the issue. Add a couple resistors and see if that solves it.

I've never used pull down resistors on the SDA/SCL of the EEPROM before. Could you explain this further please? I don't understand the purpose.

 

[ClippyTheDiode]

I think the FV-1 has internal pull-ups on the I2C lines. So you shouldn't need external ones.

Does it get any more reliable if you turn the EEPROM select switch slowly?
Try changing R29 to a 1k.

 

[Robert]

This may be a mechanical issue...

It could be that the reload is being triggered at the same instant that all EEPROMs are in a disabled state.

It might be necessary to add some circuitry to hold the Int/Ext pin in the Internal state for a slightly longer period. (RC filter or simple transistor switch)

 

[PoisonNoises]

I think the FV-1 has internal pull-ups on the I2C lines. So you shouldn't need external ones.

Does it get any more reliable if you turn the EEPROM select switch slowly?
Try changing R29 to a 1k.

I will give this a shot today and get back!

 

[PoisonNoises]

This may be a mechanical issue...

It could be that the reload is being triggered at the same instant that all EEPROMs are in a disabled state.

It might be necessary to add some circuitry to hold the Int/Ext pin in the Internal state for a slightly longer period. (RC filter or simple transistor switch)

This was my thought too. The reload triggers everytime. But it must be happening an instant before the EEPROMs has time to adjust to the correct chip selection.

Are you suggesting an RC filter between the switch and the funtion of R29 and Pin 13? Could you elaborate a little on this please?

 

[PoisonNoises]

I will give this a shot today and get back!

I think the FV-1 has internal pull-ups on the I2C lines. So you shouldn't need external ones.

Does it get any more reliable if you turn the EEPROM select switch slowly?
Try changing R29 to a 1k.

No dice here! Just amplified the pop upon changing programs, haha.

 

[Robert]

Something as simple as this might work, but C1 might not discharge fast enough to cause a 0 state on T0...

In that case you'll want to trigger it with a transistor/RC filter delay. I'm not sure if I still have the trace but it seems like there's something along those lines in the Keeley Delay Workstation.

 

[PoisonNoises]

Something as simple as this might work, but C1 might not discharge fast enough to cause a 0 state on T0...

In that case you'll want to trigger it with a transistor/RC filter delay. I'm not sure if I still have the trace but it seems like there's something along those lines in the Keeley Delay Workstation.


View attachment 69159

I'll try this first, and get back. Any recomendation on component values for C1, R1, R2?

 

[Robert]

You'll have to experiment with the values. R2 will need to be significantly larger than R1 so that the voltage on T0 is still high enough to be considered a logic high.

If all else fails I'll see if I still have that Workstation pedal and can take a peek at how it's done there.

 

[PoisonNoises]

You'll have to experiment with the values. R2 will need to be significantly larger than R1 so that the voltage on T0 is still high enough to be considered a logic high.

If all else fails I'll see if I still have that Workstation pedal and can take a peek at how it's done there.

Killer! I reached out to Robert as well. We will see if he's willing to share some secrets. Haha

-J

 

[PoisonNoises]

You'll have to experiment with the values. R2 will need to be significantly larger than R1 so that the voltage on T0 is still high enough to be considered a logic high.

If all else fails I'll see if I still have that Workstation pedal and can take a peek at how it's done there.

Tried a good number of values. Doesn't seem to be doing the trick, unfortunately.

 

[PoisonNoises]

You'll have to experiment with the values. R2 will need to be significantly larger than R1 so that the voltage on T0 is still high enough to be considered a logic high.

If all else fails I'll see if I still have that Workstation pedal and can take a peek at how it's done there.

You don't happen to still have that trace, do ya?