Dear all,
I intent to change the hardware setup of my midi accordion because I keep getting problems with the setup now.
The switches are old mechanical switches and work reasonable, but not good enough. So I want to change that and use hall effect sensors. No mechanical errors and hall effect sensors are small enough to implement in the accordion. I've looked into opto-interrupters, but they are to big for my setup.
The biggest issue is the additional amount of switches I'm going to use. Not 24 for the bass but 72 so I can use free bass. The total number of keys grows to 116 including the right hand. And I would like to use additional switches for registers which brings the total to 138 keys. This means I run out of I/O pins.
Left hand 44 notes/keys, 22 register keys and an BMP280 for bellow pressure on the i2c. Right hand 72 notes/keys.
I would ask for advice on the following options:
1 Use shift registers to read the matrixes. I've looked into using and coding shift registers. I find a lot off led options as examples, but hardly any information on coding a matrix with shift registers. The examples I do find are very complex.
2 Use two Teensy's. One to read the right keyboard, receive the data from the second Teensy, execute the major code and communicate with the PC. And a second Teensy to read the left hand matrix and send that data to the main Teensy. Using usbMIDI.read. I need to be able to use that data in the code and not just send through to the PC.
Apart from the costs of an extra Teensy, the waste of processing power and ditching the registers, which option would be the most simple to implement? I gather the second, I think I can use most of the original code for that.
With regards,
Hajo
I intent to change the hardware setup of my midi accordion because I keep getting problems with the setup now.
The switches are old mechanical switches and work reasonable, but not good enough. So I want to change that and use hall effect sensors. No mechanical errors and hall effect sensors are small enough to implement in the accordion. I've looked into opto-interrupters, but they are to big for my setup.
The biggest issue is the additional amount of switches I'm going to use. Not 24 for the bass but 72 so I can use free bass. The total number of keys grows to 116 including the right hand. And I would like to use additional switches for registers which brings the total to 138 keys. This means I run out of I/O pins.
Left hand 44 notes/keys, 22 register keys and an BMP280 for bellow pressure on the i2c. Right hand 72 notes/keys.
I would ask for advice on the following options:
1 Use shift registers to read the matrixes. I've looked into using and coding shift registers. I find a lot off led options as examples, but hardly any information on coding a matrix with shift registers. The examples I do find are very complex.
2 Use two Teensy's. One to read the right keyboard, receive the data from the second Teensy, execute the major code and communicate with the PC. And a second Teensy to read the left hand matrix and send that data to the main Teensy. Using usbMIDI.read. I need to be able to use that data in the code and not just send through to the PC.
Apart from the costs of an extra Teensy, the waste of processing power and ditching the registers, which option would be the most simple to implement? I gather the second, I think I can use most of the original code for that.
With regards,
Hajo