Page 1 of 1


Posted: Fri Nov 23, 2018 7:16 am
by Mac737
Hi Mark or anyone that can help,

I bought a Brake Pressure Gauge from Tom at Custpmparts yesterday and its very good. Fitted it to my FDS 737 DSTD no problem and powered up OK. However, can you please tell me how you connect it up so that it talks to Sim-Avionics (v.191) please?

I have ticked the "load phidgets" box in SYSBoard controller software to load Polulu phidgets, connected the Polulu via USB to my Sim-Avionics PC, loaded Maestro drivers etc. but the Gauge doesn't move as brake pressure changes. I guess that its not talking to Sim-Av?

Does the Polulu card have to connected to a sysboard card physically somewhere? Do you use FSUIPC to get them to talk to each other? How can i confirm that the Gauge and Sim-Av are talking?

I am guessing I am missing a critical step somewhere?

Many thanks and looking forward to your reply.


Posted: Fri Nov 23, 2018 12:27 pm
by Jetcos
Hi Jim,

Enable the Plug-ins

For the Brake Pressure Gauge you need to select the Polulu card in the drop-down menu for that gauge and calibrate.

Save in the SYSBoard Controller and leave that Tab so it will work.

I tested those gauges here a few months ago and they worked fine.

Posted: Tue Nov 27, 2018 9:12 pm
by Mac737
Thanks Steve for your great support.

Jsut some feedback becuase there has been surprisingly quite a few readers following this post.

Whilst I haven't quite got the Brake Gauge talking to Sim-Av yet or working, Mark Hastings has identified the potential problem (in Sim-Av) and will post a fix by the end of this week.

I am guessing that quite a few people are interested in adding this gauage to thier MIPS (?) so if it helps, I've added some info below.

I can highly recommend the seller Tom and the CustomSimParts Brake Gauge as it has the following qualities:

1. Cheap price, great service, rapid delivery
2. High quality
3. Looks great
4. Made to fit FDS MIP perfectly ..............easy to install, no cutting or modifying....use two screws, lines up perfectly.

Install Maestro drivers and software for Polulu card, connect USB, connect +5V to card, setup in Sim-AV SYSboard controller, enable plugins. That's it. Looking forward to watching it spin!


Posted: Sun Dec 02, 2018 5:21 am
by Mac737
Hi Mark and Others,
Have you had a chance to troubleshoot/update Sim-Avionics for this problem yet?

I was also wondering if anyone else can help that has used Polulu cards with this or other gauges in the mean time?


Posted: Fri Dec 14, 2018 10:56 pm
by Mac737
Hi Mark,
Thanks for incorporating the Polulu fix in v.1.93.

Unfortunately something is not still quite right as the brake pressure gauge still doesn’t work.

I have pasted some info for your review and consideration in an email to you as this format doesn't allow easy pasting. I am hoping oyu may have some suggestions once oyu see my email??


Posted: Fri Dec 21, 2018 7:28 am
by Mac737
Hi Mark,
Hoped to see a fix for the Polulu card in v.1.931

:cry: :cry:


Posted: Sun Dec 23, 2018 6:36 am
by MarkHastings
I have no issue getting the card to work here...
I'll ask Steve if he has a card available and would have time to check it the next time he's in.

Posted: Sun Dec 23, 2018 9:40 pm
by Mac737
Thanks Mark/Steve.....

Really good to hear that it does work in your testing.......must be some minor setting that I haven't got quite right so I'll keep testing because I want to add the CustomSimParts flaps gauge as well, so I have to get it working.

I'll wait to see what Steve comes back with his testing as you suggested.




Posted: Thu Jan 10, 2019 8:53 pm
by Mac737
Hi All,
Thanks to Mark and Steve, this issue has been resolved. The Brake Pressure Gauge now works perfectly!! :D :D :D

I thought this exercise was very useful and very informative because I am sure most of us want to add a Gauge here or there at some time.

So, this is what you will need and what I have learnt for adding Gauages with Pololu cards (I'll try to provide the help in a logical order):

1. I have a FDS DSTD MIP so the CustomSimParts Brake pressure gauge was the choice becuase it fits perfectly......... no mods, no plates or cutting required
2. You need a Pololu-Maestro card to connect gauge. You will also need a FDS R1X relay card as well.
3. READ ALL OF THE MAESTRO SOFTWARE shortcuts sorry....Load Maestro drivers and software.....follow instructions to check drivers are loaded properly.
4. Connect +5V and ground to Pololu card for Servo power
6. Connect USB cable (mine goes straight to Sim-Av PC) >connect Gauge cable to Output on Polulu (NOTE THE OUTPUT NUMBER THIS IS VERY IMPORTANT LATER ON......They are numbered 0-5 on the Pololu i.e a total of six.....I'll come back to this. I USED OUTPUT #1
7.Enter Maestro Software.....leave ALL settings to default. Select Output where your gauge is connected....use slider and gauge will must work or you have done something wrong.

OK, you have proved that it all to get Sim-AV talking to it. You will need the soon-to-be released Sim-Av v.1.94 !

8. Connect R1X via USB (mine goes straight to Sim-Av PC)
9.Connect +5V that normally goes to Polulu to COM on R1X relay #1. Connect another wire to NO on relay and connect this to the Polulu card where you would normally have put the +5V wire. THIS IS VERY IMPORTANT SO THAT THE GAUGE AND BACKGROUND LIGHT ARE OFF IN THE "COLD AND DARK" STATE!
10. Go to Sim-Av SYSBOARD software
11. Check box for enabling Plugins
12. Go to Gauges "brake pressure gauge" menu the pulldown menu choose Pololu. Pull down menu for OUTPUT, choose output 2 (NOT 1 because in Sim-Av outputs are numbered Pololu Output #1 = Sim-Av Output# 2...............told you it was important!
13. Go to Output Assignments "AC POWER BUS 1" (corresponds to your wires on R1X relay 1)
14, Go back to Gauges TAB.......use slider to check that gauge needle moves.....set MIN and MAX for gauge here
15. So, if you are successful, the gauge backlight should be OFF in the COLD and DARK state and backlight should be ON when you switch AC power on with your Overhead!!

When you power down after your flight is complete i.e. HYDRAULICS OFF, the brake pressure will go from about "3" down to "1" (NOT ZERO) as the hydraulic line remains pressurized. I am fairly sure this is the REAL situation.

TAKE A DEEP BREATH......and congratulate yourself!

Thanks again to Mark and Steve................I hope this helps!