vince.cimo
Well-known member
Hello. I'd like to create a usb MIDI based motorized fader controller, using the Motofader 64 as a starting point. This unit is meant to be a controller for a EQ Station 8, and doesn't work on its own or output any MIDI in its current state. It communicates solely with the EQ 8 unit via DB9 serial cable.
The Motofader 64 features 29 motorized ALPS faders, controlled by 15 A3966 motor controllers. The fader levels are read by 4 MCP3008 A/D converters which communicate via SPI.
The unit has a large 7v DC power supply and does it's own I/O using 2 FPGA chips over an encrypted serial protocol.
Clearly, the easiest way to achieve my goal would be to hook into the serial port of the unit then translate the serial commands that move the faders into MIDI, but TC Electronics is not willing to provide me with a communication protocol guide, and the unit is in a 'disabled' state until it receives some encrypted handshake from the mother EQ unit. (I've tried hooking a logic analyzer up to see if anything was sent when I moved a fader, and there's nothing).
So, i'd like to hack a Teensy 3.2 onto the board, cut the connection to the FPGA chips and just utilize the rest of the board and components.
I'm not very familiar with motor control or SPI, and would love some help.
A few specific questions:
1. The A3966 (datasheet at this link) each control 2 motors. Does this mean I would need to dedicate two analog output pins on the teensy for each A3966?
2. While I could potentially figure out how to communicate with one of the MCP3008's (datasheet), I don't really know how to go about communication with all 4 at once. Since the
board is pre-made and I don't have a schematic, how do I find out which is the master and which are the slaves? I've read the PJRC guide on SPI, but I'm still kind of confused.
3. I don't really understand the A3966 datasheet. My best guess is that I hook up analog out pins from the teesny to pins 4/5 for motor 1 and 12/13 for motor 2, then leave the rest of the connections on the existing circuit board intact.
4. The open frame 7vdc power supply that powers this unit is kind of massive, and if possible, I'd like to replace it with something smaller. How can I go about measuring how much amperage the unit is drawing and if there's anything else I need to know before replacing the open frame supply with a small wall wart?
5. If I do need two analog outs per PWM, that puts me at 29 PWM outs, whereas the Teensy 3.2 only has 12. How can I reconcile this? Is there a multiplexer or something of the sort that would solve this problem?
I've attached a photo of the PCB. Thanks in advance for your advice!
The Motofader 64 features 29 motorized ALPS faders, controlled by 15 A3966 motor controllers. The fader levels are read by 4 MCP3008 A/D converters which communicate via SPI.
The unit has a large 7v DC power supply and does it's own I/O using 2 FPGA chips over an encrypted serial protocol.
Clearly, the easiest way to achieve my goal would be to hook into the serial port of the unit then translate the serial commands that move the faders into MIDI, but TC Electronics is not willing to provide me with a communication protocol guide, and the unit is in a 'disabled' state until it receives some encrypted handshake from the mother EQ unit. (I've tried hooking a logic analyzer up to see if anything was sent when I moved a fader, and there's nothing).
So, i'd like to hack a Teensy 3.2 onto the board, cut the connection to the FPGA chips and just utilize the rest of the board and components.
I'm not very familiar with motor control or SPI, and would love some help.
A few specific questions:
1. The A3966 (datasheet at this link) each control 2 motors. Does this mean I would need to dedicate two analog output pins on the teensy for each A3966?
2. While I could potentially figure out how to communicate with one of the MCP3008's (datasheet), I don't really know how to go about communication with all 4 at once. Since the
board is pre-made and I don't have a schematic, how do I find out which is the master and which are the slaves? I've read the PJRC guide on SPI, but I'm still kind of confused.
3. I don't really understand the A3966 datasheet. My best guess is that I hook up analog out pins from the teesny to pins 4/5 for motor 1 and 12/13 for motor 2, then leave the rest of the connections on the existing circuit board intact.
4. The open frame 7vdc power supply that powers this unit is kind of massive, and if possible, I'd like to replace it with something smaller. How can I go about measuring how much amperage the unit is drawing and if there's anything else I need to know before replacing the open frame supply with a small wall wart?
5. If I do need two analog outs per PWM, that puts me at 29 PWM outs, whereas the Teensy 3.2 only has 12. How can I reconcile this? Is there a multiplexer or something of the sort that would solve this problem?
I've attached a photo of the PCB. Thanks in advance for your advice!