MESA 7i96+7i76 : How to add 4 PWM and to connect 3 SSERIAL daughterboards ?

Thanks a lot for your replies.

And, instead of using dir/step output I need to control mu steppers, what about using 1 of the 6 GPIO outputs of the 7i96 for TX, and one of the 7i96 GPIO inputs for RX ?

What do you think ?

BTW, Thanks a lot PCW for the advise about bitfiles ! And I am interested to know more about this read_request function... What is this doing ?

For the SSerial interface, if I understand correctly, using the Encoder intput and Step/Dir output will directly give me différential TX+ TX- and RX+ RX- signals with no need for an external RS485/RS422 transceiver ?
Is that correct ?
It should be the same for the regular GPIO outputs of the 7i96 tTB3, pin 13 to 24) as they are differential outputs...

Unfortunately the power outputs and isolated inputs are about 1000 times too slow for SSerials 2.5 Mbaud data rate, Much better at what they were designed for, driving relays/solenoids and sensing limit switches

edit

The isolated outputs are not differential, they are 2 connections to a isolated MOSFET switch

Got it. Thanks !

Thanks for your help.

I am going to go with software PDM for the heater control as you suggested. It make sens.

For the SSerial board, by connecting the "Enable" input of the stepper drivers to 2 GPIO, I'll be able to connect 2 stepper drivers to one DIR/STEP output. This will free one DIR/STEP output for the 2 TX signals to SSerial daughterboards, and I'll use the ENCA and ENCB inputs as 2 RX as you suggested. With the SSerial interface that is already on the 7i96, I'll have the 3 serial interfaces I was looking for.

I'll have to generate the corresponding bitfile (following your adives, should be no big deal... or I'll ask few questions on this forum) and I still have to make the wiring of the CNC-3D printing machine. It may take few weeks daught as I have my job and other projects running.

Best regards.
Bernard.

Yes the 7i96 has 1 25pin header, but I already use it for a 7i76 daughterboard. This is why I'll need a workaround...