Néal Zheimer

Thanks for your support but this thing is in stand-by for the moment.

Thanks for the info, greatly appreciated! (and a lot to process). :thumbsup: I think I'm gonna go with I2C digipots chips, seems like a smarter choice (even if it means, I'll have to solder TSSOP chips). To sum up, I'll build up a MBHP_IIC digipot module allowing the use of up to 12 digipots using three AD5254 chips (one could go to up to 16 digipots using 4 of them which is the maximum on one I2C bus). Now I have to come up with a schematics... Cheers G

Thanks for the correction, English is not my mother language so I can get confused sometimes (as long as you get my point...). Yep, the versatile volatile ( :thumbsup: ) feature isn't really needed since the digipots will be controlled by the box. I check in more depth the coding part (I'm a computer scientist) and indeed it doesn't seem to be too hard to get (I thought I had to write some ASM code...). About the SPI, yeah it's a bus but if I get this right, you need the same number of Slave Select (SS) wires than the number of chips you want to control no? How do you select the chip your talking to with the J8 interface? (I might be missing something here). I couldn't find the SPI functions for MIOS8 neither... And found it on the MIOS32. I found a PDIP 4-channel digital potentiometer too. Still wondering which tech to go for... PIC or STM32 Core? I2C or SPI? But I'm moving forward in the general comprehension, it's a good thing! Cheers G

About I²C After some interesting reading about I2C protocol, maxim-ic and ucapps.de documentations here is where I stand: On a single I2C bus, there can be a maximum of 8 MAX5418 chips (due to addressing limitations) A PIC or STM32 Core module can address only one I2C bus (on J3 J4) It would require coding a new firmware according to the IIC_MIDI Module page: Based on that, I'm starting to wonder if I'm not WAY over my head (even if learning about this stuff is kind of fun anyway). If someone reads any mistake in what I wrote (which in NOT impossible), I'll be glad to hear about it. Cheers G Edit: Found a TSSOP chip featuring a non-volatile quad I2C controlled 100Kohms digipot, the AD5254, looks promissing...

100Kohms linear resistances are needed and found on those chips. So far, I can see three choices for digital pots found at maxim: - the non-volatile MAX5418 100Kohms chip with 2 wire I2C interface (I've just disovered about the I2C interface). On power up, the digipots go to the last memorized position. - the non-volatile MAX5423 100Kohms chip with 3 wire SPI interface (I've just discovered about the SPI interface too). On power up, the digipots go to the last memorized position. - the volatile MAX5401 100Kohms chip with a 3 wire serial interface (looks like SPI). On power up, the digipots go to half the course. Does the core module can "speak" I²C/SPI? Can it "speak" to 10 of them? (Any lead on the how?)

What do you mean by the required voltage? I what thinking of replacing the sliders of the pedal by some digitally controled resistors but maybe you have something else in mind. I've started to search more deeply into the documentation of the AOUT(_NG/LC) modules and while I understand every concepts, I think I'll need help about the technical details like how to connect the (STM32?) Core module to AOUT modules but I'm not there yet... :)

Hi Neither do I, I wasn't considering soldering motorfaders in the pedal don't worry. I just think MF are the best way to operate this thing allowing the preset recall feature. Thank you very much! I found all sliders are 100Kohms linear pots. R41 100K LIN (Trigger) R61 100K LIN (Sub-octave) R6 100K LIN (Guitar) R29 100K LIN (octave) R36 100K LIN (Square wave) R101 100K LIN (Attack delay) R92 100K LIN (Start freq) R65 100K LIN (Stop freq) R74 100K LIN (Sweep rate) R86 100K LIN (Resonance) In lack of another way, I could try this, it's a cheap way to go! Maybe with some nice softwate calibration, it could do the trick... I guess something like this or this would be better but I start to feel way over my head. I'll search again for that. Thanks for the leads! Cheers G

Hello ! After a little more time thinking about it, I may split this project in two parts: 1) a midi controller for the pedal (ie. one CC# for each slider on the pedal). 2) a midi interface with sliders and preset management. I will focus on the first part first. The only thing I miss (apart from experience) is a way to control a resistance value from the circuit. And yeah, I'm kind of a electronic newbie. G

Hi I'm a new guy here (hello everybody) and I have browsed this website and the UCapps website for quite a while now and I think I need some guidance. I would like to digitally control an analog pedal for bass guitar. This pedal sounds great and is controlled by 10 analog sliders, the only thing lacking on it is preset memorization and eventually expression pedal control of one (or more) parameter(s). The goal: - control each of the 10 linear potentiometers of the analog pedal - allow real-time control of every parameter - add presets memorization and recall - (later on) add expression(s) pedal(s) control of one (or more) parameter(s) while playing My first guess would be to build up a digital interface featuring ten motorized faders (one for each pedal parameter) and a set of buttons (or foot-buttons) to store and recall presets. Recalling a preset would change the parameters on the pedal, display it on the motor sliders and thus allow live modifications. All those things being controlled by (I think) a STM32 based core and an AIN module two MF modules. For what I've seen of the uCApps website, I think it would be doable. Q1: Do you guys think I'm going the right way about this? I couldn't find a way to control variable resistors from a midibox. AOUT module allows variable voltage output but I'm stuck here... Q2: Can a box control variable resistors? To my opinion, motorized sliders are well adapted to this use. It allows both control and display of the settings but I found out that motorized faders aren't cheap (21€ each on ebay and I need 10 of them...). Q3: Can you guys think of another way around motor faders? Q4: Am I being clear? Thanks for reading this far :) Guillaume