midi.sendSysex question, multiple parameterNumbers

General discussion
1

Hi Guys, can the midi.sendSysex command send out multiple parameterNumbers like the JSON code can take as arguments?

In LUA, midi.sendSysex (PORT_1, { 0x43, 0x10, 0x5E, 0x60, 0x00, 0x03, 0x00, value })

Can the ‘value’ LUA piece above be crafted to splice two parameterNumbers together like I can in JSON:
“data”: [
“F0”,
“43”,
“10”,
“5E”,
“60”,
“00”,
“29”,
“00”,
{
“type”: “value”,
“rules”: [
{
“parameterNumber”: 94,
“type”: “sysex”,
“parameterBitPosition”: 0,
“byteBitPosition”: 3,
“bitWidth”: 3
},
{
“type”: “sysex”,
“parameterNumber”: 95,
“parameterBitPosition”: 0,
“byteBitPosition”: 0,
“bitWidth”: 3
}
]
},
“F7”
],

2

Yes it can. As you see, the payload in the sendSysex statement is a table where each element represents the value of a byte pair (the value does not need to be in hex format, by the way). You can use any constant or function in here. Also the value belonging to a parameter.

Some sysex commands require you for instance to add a device ID, a MIDI channel or a checksum to a sysex. These too are just set up as elements in the payload table.

3

Just note that the data you supply to the midi.sendSysex() should not include the F0 and
F7 bytes.

1 Like
4

as you are in Lua you can assemble array of the bytes as you wish. see the example below. It is just important to keep bytes in 7bit number range.

    -- you need to know what device to use
    local yourDeviceId = 1

    -- get values of the parameters
    local parameter94 = parameterMap.get(yourDeviceId, PT_SYSEX, 94)
    local parameter95 = parameterMap.get(yourDeviceId, PT_SYSEX, 95)

    -- perform bitwise operations to compose the byte value
    -- note, this replicates your JSON example
    local byteValue = ((parameter94 & 0x07) << 3) | (parameter95 & 0x07)

    -- you can optionally check if the byteValue is in 7bit range
    assert(byteValue == (byteValue & 0x7F))

    -- you can optionally just trim it to 7bit range
    byteValue = byteValue & 0x7F

    -- send the message out
    midi.sendSysex (PORT_1, { 0x43, 0x10, 0x5E, 0x60, 0x00, 0x03, 0x00, byteValue })
5

Thanks for the example Martin, I haven’t ever used any of the bitwise operations and an example teaches me better than anything else!
NewIgnus, I can see now that I’m going to have to go at it differently than the JSON code, I was hoping there was a shortcut. I need parameterMap.get’s to snag the values first.
Oldgearguy, thanks. I do know not to include the F0 and F7 bytes, they’re excluded from my midi-sendSysex example.

1 Like