DIY Daystate GCU v5 (Red Wolf) programmer

How to build your own Daystate GCU v5 programming tool, this is the GCU found in the Red Wolf. The GCU communicates with the Daystate programmer via a '1 wire' serial interface, to build one of your own you will need the following components:

1 x 4k7 1/4 Watt 5% resistor (EBay $3.49 for 100)

1 x 1N4148 Diode (EBay $1.59 for 10)

1 x JST SH 1.0 5 pin plug with tails (EBay $3.49 for 10)

1 x USB-UART 5V TTL adapter (EBay $2.58 each)

All these parts can be found easily on EBay or Amazon although you may end up buying a pack of 10 or a 100 diodes and resistors. Even if you don't have any of these parts on hand you can still build the hardware for less than $20

Once you have these parts you will need to assemble them as shown in the schematic diagram below

View attachment 193719

Note the pin number on the programming header of the GCU

View attachment 193734



Depending on the type of USB-UART adapter you purchased you may be able to add the diode and resistor directly to the adapter


View attachment 193741

A fully assembled adapter and cable look like this (only 3 of the 5 pins are required)


View attachment 193747

Now that you have your hardware assembled you can plug it into your PC and follow the vendor's instructions to install drivers etc. Next you will need to download some software from Github.

https://github.com/DaystateRebel/gcui

The gcui tool is written in Rust (https://www.rust-lang.org/tools/install) but for convenience I have made a compiled Windows binary available here:

https://github.com/DaystateRebel/gcui_binaries/blob/main/gcui.exe

Download the exe (or build from source code if you prefer) and put it in a directory on your hard drive. Open a command prompt ad "cd" to the directory where you saved the executable. Gcui can perform the following functions (replace comX with the name of the USB-UART hardware, you'll find it in Device Manager)

To read power settings from the GCU

$ gcui.exe --port=comX --read --filename=file.csv

To write power settings to the GCU

$ gcui.exe --port=comX --write --filename=file.csv

To read the current air pressure from the GCU

$ gcui.exe --port=comX --pressure

To read the current pulse duration from the GCU

$ gcui.exe --port=comX --pulse

To read the GCU version

$ gcui.exe --port=comX --rwversion

The power settings are read to / written from a .csv which you can open in Excel/Google Sheets

View attachment 193776

Congratulations, you can now easily download, edit, save and reload power settings from your computer instead of writing them on bits of paper - welcome to the 21st Century!

Coming next - What do all these numbers mean and how do I recalculate HS & LS? I will also be adding support for "locked power" mode to gcui so we a full featured alternative to the current hardware programmer

Happy Hacking

Rebel
Ok I'm lost already, put the hardware together and went to the links above and the second 2 links don't work and the first doesn't have an exe file
 
Click on the first link that worked once open click on daystate rebel name you ill see a tab saying repositories, click on this tab then scroll down to WinGCU
Click on this then go down to releases click on this and you can download the WinGCU 0.3 zip file yourself. Hope this helps
Awesome sir! Thank you. Now I have a concern. I hooked this up to my Daystate Pulsar HP and this screen shot is my current settings. Question is how high on the setting can I go without compromising or damaging anything. What is a safe upper limit.
Screenshot (72).png
 
Click on the first link that worked once open click on daystate rebel name you ill see a tab saying repositories, click on this tab then scroll down to WinGCU
Click on this then go down to releases click on this and you can download the WinGCU 0.3 zip file yourself. Hope this helps
Settings on my Pulsar seem pretty high...251Bar on High? Much higher than settings on this video, skip to 2min 11 sec for his settings. Maybe I'm maxed out already?
 
I can't really help with the settings as mine is sub12 as being in the uk only thing i can do is point you in the direction of airguns of arizona redwolf progamming video that shows you what you can go up to for american air rifles
I just found that vid and another one where he goes even higher than what I had set at. I didn't go as high as on this vid I just set it high enough to shoot 13.43g JSB Knockouts @ 1015fps
This pic is not my settings but from a video I found.
My High Pulse setting is 2700 and voltage is 65.25 so both still quite a bit lower than what it is capable of.
Still trying to figure out the HS and LS is for and ideal setting
Screenshot (75).png
 
I believe the only two settings you need to change are the volts and pulse length with the pulse length being the priority in all the videos i have seen they never change hs and ls settings. There is a good video on daystate rebel on a wifi gcu version which as as more control you can even degass the cylinder with it but he never finnished it.
 
I believe the only two settings you need to change are the volts and pulse length with the pulse length being the priority in all the videos i have seen they never change hs and ls settings. There is a good video on daystate rebel on a wifi gcu version which as as more control you can even degass the cylinder with it but he never finnished it.
I've watched a few vids and never saw anyone mess with the HS or LS settings but they always have a bit of a difference on them, on the settings I have mine are the same 4.1 and 4.1 shouldn't one be higher than the other?

I've seen different settings on different videos, I wish I knew what is best. One vid shows a lower voltage in the high 50's but pulse over 3300 to achieve high velocities and other with higher voltage like 69+ but lower pulse duration to achieve those velocities...want to know how these work together and is it better or more efficient with high volts and lower pulse or lower volt and higher pulse...if you know of a vid explaining that would love if you share it...thanks for all your feedback. From what I understand the pulse is like the duration in milliseconds

Screenshot (72).png
 
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I'm starting to understand a bit more on how it works, but one thing I don't get is the High Slope and Low Slope. With the calculations it always show a number in the hundreds, but on my program it is HS 4.1 and LS is 4.1 and shouldn't they be different? Below pic is image of what was used higher up in the thread as an example...HS is 352 and LS is 160 on power level1

1754873214854.png


Here is my readout...both are 4.1
Screenshot (72).png
 
Mine is approximately 58/59 volts with a pulse length of 1695 on the high power setting but mine is sub 12
Why does the spreadsheet show voltage 850? Even on my spreadsheet that I exported, it shows 850 but on the program it show 63.75 volts....ooops, I'm guessing that's 850 bits which converts to 63.75 volts
 
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This may explain it i am new to this as well
Regards

View attachment 585286
That helped me understand how the voltage works but still can't figure out the High Slope and Low Slope
These are the settings my Pulsar came with, on the printout the HS and the LS are 128 but on the application it show 4.1 for both, can't figure out how that converts


high_pressuremid_pressurelow_pressurehigh_pulsemid_pulselow_pulsehigh_slopelow_slopevolts
925​
750​
575​
2750​
2575​
2400​
128​
128​
850​
925​
650​
425​
2350​
2125​
1950​
2350​
99​
850​
925​
625​
350​
2100​
1865​
1685​
2100​
83​
850​
Screenshot (72).png
 
So I've been tweeking the settings a bit and turns out was pretty damn good just as it was when I got it.
Originally it was set at a lower voltage and higher dwell (pulse) and at the High Power setting it was shooting 13.43g slugs at 978fps. I upped the voltage and lowered the dwell to get about the same velocity but now it is shooting 13.43g slugs @ 974fps on Mid Power setting and 1009fps on High Power setting and on Low Power setting I'm at 919fps with the 13.43g. Tomorrow I'll hit the range and see which groups the best and then set a tune for 10.03 MK3 Knockouts. Debating on setting a tune for heavier slugs like the 15g Take Aim Slugs of which I had a few samples and shot under a dime size group @ 50 yards with just a bipod and no rear bag.

Values (4th tweek)Power Setup 1Power Setup 2Power Setup 3
High Pulse (us)2750us
2550​
us2350us
Mid Pulse (us)2575us
2325​
us2115us
Low Pulse (us)2400us
2150​
us1935us
High Pressure (bar)251bar
251​
bar251bar
High Pressure (bit)925bit
925​
bit925bit
Mid Pressure (bar)209bar
184​
bar178bar
Mid Pressure (bit)750bit
650​
bit625bit
Low Pressure (bar)166bar
129​
bar111bar
Low Pressure (bit)575bit
425​
bit350bit
Volts65v
65​
v65v
Volts (bit)bitbitbitbit
HS
4.1​
3.33​
3.2​
LS
4.1​
3.17​
2.66​
ProjectilePower Setup 1Power Setup 2Power Setup 3
BrandJSB KnockoutJSB KnockoutJSB Knockout
Weight
13.43​
13.43​
13.43​
FPS Avg
1009.11​
973.75​
919.3​
Extreme Spread
16​
9​
8​
Group Size