One other thing to add....It's good practice to loop-back the end of the serial chain to your controller so you can run diagnostics on the serial chain.
On my projects, I run the clock and data signals back to the Raspberry Pi or FPGA so I can verify the integrity of the chain. If the clock doesn't wiggle, the chain is definitely broken. The other reason is that looping-back the clock allows you to drive clock and data signals in the opposite direction, which improves the timing margin for hold-time. This has been common practice in chip design for decades. Reading back the data and comparing against a delayed version of what was sent will tell you if there are any shifting problems. You can also develop code to measure the length of the chain, set or sample specific bits, and speed tests (FPGA; RasPi is too slow). On Sunday, August 14, 2022 at 1:35:32 AM UTC-7 M1 wrote: > Good that you mentioned ShiftOut. On that note… > > > > I use an ESP-8266 for most of my projects (specifically the WeMos Mini D1). > > Limited in PINs, but I want to control many steppers, so I use the > mentioned ShiftOut. > > > > Basically, using 595s (4 of them), I control 8 stepper motors. A 595 > having 8 outputs and the steppers need 4, I get to control 2 per chip. > > > > In the reverse, I have 8 switches (end points/stops) for the 8 steppers. > > > > All happily controlled by a single WeMos. > > > > Of course with 8 steppers * 4 wires each…. It’s a jumbled mess in > prototyping. > > > > Michail > > > > *From:* [email protected] <[email protected]> *On Behalf > Of *Richard Scales > *Sent:* Saturday, August 13, 2022 9:42 PM > *To:* neonixie-l <[email protected]> > *Subject:* Re: [neonixie-l] Re: Nixie Clock - Direct Drive HV5530 > > > > I've used HV5522 and HV5622 a lot without any issue - I always use a > CD40109B level shifter to convert from 3v3V or 5V to 12V (I know many do > not). > > > > In Arduino Land there is a function called ShiftOut which does all the > required clocking - it's for 8 bits as standard but can easily be re-worked > for however many bits you want. > > > > I have one clock with 4 x HV5522 in series for which I made a 128 bit > ShiftOut function. > > > > See here for details of the shiftout process: Arduino shiftOut(): Control > chips with a 3 wire Serial Interface. (best-microcontroller-projects.com) > <https://www.best-microcontroller-projects.com/arduino-shiftout.html#:~:text=Arduino%20shiftOut%20is%20a%20purely%20software%20implementation%20of,data%20input%20%28the%20equivalent%20software%20function%20is%20shiftIn%29.> > > > > It's an interesting page with scope traces to help explain. > > > > Ultimately I moved over to using SPI transfers which are driven purely by > the processor but the theory is all very similar. > > > > - Richard > > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/850d8597-ee90-442e-9ad8-d822a2284a14n%40googlegroups.com.
