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SHC Connection issues

Matthewabey@...
 
Edited

For the life of me I can't get it to connect to my onstep Max 2.1. I have tried every combination of st4 settings, wiring, Ect. Any help would be appreciated. I even soldered the wires direct to the connector to eliminate any crimping issues.

Howard Dutton
 

No known issues.  3X different SHC's all run fine on T3.2, ESP32, T3.5, T3.6 here.  Just checked the very latest Master branch (both SHC and OnStep) on a MaxPCB2/Ethernet.

Matthewabey@...
 

I'm starting to wonder if I have a bad teensy 3.2. It boots up with the splash screen but eventually says faild to connect.

Jerry
 

That’s the typical failure to communicate when it can’t talk to the board. I removed the pull-ups for the ST4 in my max pcb and it made the connection much more reliable and robust. 

-Jerry

On Jun 29, 2020, at 4:28 PM, Matthewabey@... wrote:

I'm starting to wonder if I have a bad teensy 3.2. It boots up with the splash screen but eventually says faild to connect.

Matthewabey@...
 

So you removed the resistor array from the max PCB and it helped?

Howard Dutton
 

On Mon, Jun 29, 2020 at 04:31 PM, Jerry wrote:
That’s the typical failure to communicate when it can’t talk to the board. I removed the pull-ups for the ST4 in my max pcb and it made the connection much more reliable and robust. 
Always robust and reliable here with the resistor networks in.  If that resistor network is not in, be aware that normal ST4 equipment will be subject to problems.  Been there done that.

Jerry
 

Immensely, before I removed it I had to use a cable that was just a few feet long. I had originally bought a 10' coiled cord and that just would not work. When I started to used the onstep with my servo drives I had dropouts even with the short cable. So I started looking at the signaling between the SHC and the board. I pulled the resistor network out and my interference issues went away and I was even able to use the coiled cord I had bought before.

I tried this with both my Analog SHC as well as the standard SHC and same results. Its worth a try.

-Jerry

On Mon, Jun 29, 2020 at 4:33 PM <Matthewabey@...> wrote:
So you removed the resistor array from the max PCB and it helped?

Howard Dutton
 

On Mon, Jun 29, 2020 at 04:38 PM, Jerry wrote:
Immensely, before I removed it I had to use a cable that was just a few feet long. I had originally bought a 10' coiled cord and that just would not work. When I started to used the onstep with my servo drives I had dropouts even with the short cable. So I started looking at the signaling between the SHC and the board. I pulled the resistor network out and my interference issues went away and I was even able to use the coiled cord I had bought before.
 
I tried this with both my Analog SHC as well as the standard SHC and same results. Its worth a try.
Any theory as to why the Teensy's ST4 pins can't drive a 1.6mA load at "high speed"?  Heck I2C does it all the time.

Matthewabey@...
 

Awesome thanks guys I just Amazoned a new teensy and if that doesn't work I'll pull the resistors. 

Howard Dutton
 

On Mon, Jun 29, 2020 at 04:44 PM, Howard Dutton wrote:
On Mon, Jun 29, 2020 at 04:38 PM, Jerry wrote:
Immensely, before I removed it I had to use a cable that was just a few feet long. I had originally bought a 10' coiled cord and that just would not work. When I started to used the onstep with my servo drives I had dropouts even with the short cable. So I started looking at the signaling between the SHC and the board. I pulled the resistor network out and my interference issues went away and I was even able to use the coiled cord I had bought before.
 
I tried this with both my Analog SHC as well as the standard SHC and same results. Its worth a try.
Any theory as to why the Teensy's ST4 pins can't drive a 1.6mA load at "high speed"?  Heck I2C does it all the time
If there is a known reason I could move to 3.3k or 4.7k and strike a different balance between EMI/RFI immunity (in normal ST4 mode) and cleaner signals for the SHC.

Howard Dutton
 
Edited



That display is not the correct one for this project... did you swap the connections or what???

The correct order of pins is Gnd, VCC, SCL, SDA.

Matthewabey@...
 

Haha yes I had this one laying around so I swapped the gnd and vcc with wires it works.

Khalid Baheyeldin
 

Matt,

Check the network resistor, and make sure that it is inserted with the correct pin order.
If it was put in reversed, it would cause problems.

Howard Dutton
 

Define "it works"...

You got a message saying that it couldn't connect or does the screen just go blank

On Mon, Jun 29, 2020, 8:05 PM <Matthewabey@...> wrote:
Haha yes I had this one laying around so I swapped the gnd and vcc with wires it works.

Matthewabey@...
 

Screen works fine it shows the onstep splash screen. And I didn't realize the resistor had a pin order, Is it the large one in the shc?

Dave Schwartz
 

Yes, they do have a pin order. Pin 1, the one on the end with the dot on the side with the printing, goes in the square pad.

Matthewabey@...
 
Edited

Thank you guys so much that was my issue, I had one resistor array backwards.


I'm up and running now after some surgery and a huge mess of flux.

Howard Dutton
 

On Mon, Jun 29, 2020 at 07:37 PM, <Matthewabey@...> wrote:
Thank you guys so much that was my issue, I had one resistor array backwards.
Glad you are up and running.

There was a note in the SHC Wiki build instructions about this already, it's now highlighted in yellow.
I also widened the SHC PCB silkscreen around the RPs' pin 1 to really make it stand out.

Matthewabey@...
 

Thanks Howard, and yeah it was an error/oversight on my part.

Howard Dutton
 

On Tue, Jun 30, 2020 at 04:23 AM, <Matthewabey@...> wrote:
Thanks Howard, and yeah it was an error/oversight on my part.
It happens.  It's also difficult as heck to see the pin-1 marking on the resistor networks specified so it doesn't exactly jump out at you.  I hate to move away from spec'ing Mouser.com parts and see no suitable alternatives there though.