Details

This guide will show you how to properly connect the Gemini Tx for testing

Overall our goal is to:

1- connect the TX-16 Controller to the Ep1 on the Gemini Board

2- pair the Gemini Board to the EP dual on the Huston Drone

3- use one of the 2 ways to get data

4- graph the data and use that to debug

First Step (Connect the Gemini Board to the EP dual and the EP1 to the Controller)

First Pair Connect:

First Connect Gemini Board using binding phrase: wargify-gemini

• Turn the Gemini Board on by connecting it to a dc power supply with 5V and 0.5 A (recommended) it should light up after that and the antenna should blink green

• Connect to the ELRS-RX wifi after its on for 1 min

Open

Second connect EP-dual on the Huston drone using binding phrase: wargify-gemini

• you can also use Wi-Fi here so just turn on the Huston drone for 1 min by connecting the usb-c

• and connect to the Wi-Fi after it enters Wi-Fi mode where its going to blink green

• the Wi-Fi name should be the same and the process is the exact same

• it might be a bit confusing since both have the same Wi-Fi name in that case turn off the Gemini board and connect to the Wi-Fi after that so you know your on the drones Wi-Fi

• if its connected when you finish this guide it should light up blue if not try turn it off then on again (remember that this is something you check after you setup your binding phrases)

Second Pair Connect:

Third connect EP1 using binding phrase: wargify

Your going to need to download a Program Called Express Configurator

Your need to go to Target section

Open

and make your Binding Phrase wargify in the Binding Phrase Section Below:

Fourth Connect TX16 controller using binding phrase wargify:

The TX 16 Controller should already have the same binding phrase as the EP1

You set it up like this:

• Try use the one with the pink ziptie as it is for testing purposes

• Then after you open it make sure to turn the throttle low to avoid a warning and fix the controls or you can ask an available lead or member to help you

• Next you press the SYS button and go to Express-LRS and press the scroll wheel

• if you keep seeing a loading screen then it might be because you have the wrong output frequency (ask a member or lead to set it up for you)

• then go to wifi connectivity and set wifi to on not (wifi-rx just wifi)

• Then on your device connect to Express-TX (password is expresslrs) and you should see the same menu again so just set the binding phrase to wargify.

Getting Data:

• There are two ways you can use to extract the data from the connectors onto your computer in raw form

• Before you do any of the two ways connect the usb debug/flash connector to your computer and make sure you can see the board on the hardware manager its should be in the COM/PORTS sections and for me its was labeled COM8 but it might change.

First Way (The Fun Way):

The Second is still the better way when flight testing since it doesn't need you to be near the circuit but if you need to get the bud rate the first way is the better option

You don't need jumpers when getting the data using this method

You can use the Logic Analyzer There should be one is the bay look for one named Saleae (be careful when your probing the pins on the connectors as you can cause damage to it)

• I recommend having the schematic and pcb of the Gemini Tx board open so you can know what pins to probe Gemini Board

• Take two Probes from the logic analyzer you should have a pair of wires on each column. In here the colored one means signal and the black one under each colored should go to ground.

• Connect one colored wire on on each of the two probes your going to use and then connect the probes to the pass RX and Pass TX. Connect your probes to the pass RX and pass TX pins on the J2 and J4 connectors.

• Now Take the respective black wires and connect them to the negative terminal on the FAN connectors labeled P1 and P2 (you can connect it to any ground not just these)

• Now you should be getting data but to view it you need to download another program called Logic

• The nice part is you don't need to change anything on that program the only thing you need to change is

• the bud rate (go to devices and change it there). The bud rate depends on the bit length so check when one bit was sent and find the length of that bit (around 2.52 microseconds) then you do 1/ bit length to get the bud rate. You shouldn’t need to find out assuming the firmware was setup properly it should be in the GitHub which is linked in the python step.

After You Setup the bud rate you should be able to run or press R then see data coming in. It might come in fast so try and pause it after you see a quick spike and then zoom in with your mouse and you should see this:

From this you can get the bud rate and you can get the data from the TX and RX pass connectors just like the second way (python way)

Second Way (Python: The Boring Way):

The Second is still the better way when flight testing since it doesn't need you to be near the circuit but if you need to get the bud rate the first way is the better option

Jumper cable setup

Before you get the data from the USB onto your computer you want to actually output the data on the Gemini board to the USB flash/debug connector then connect that on your computer (Look at the J3 connector below) that's where you want your data to come from.

For you to direct the data coming from the ESP Pass RX and ESP Pass TX your need to use jumpers so they can both output to the J3 connector

How to Setup your Jumpers:

• First Get two female-female jumper cables

its pretty simple I do recommend you have the schematic open and look at the names from there then switch to the 3d section to see exactly where the connector am talking about is: here (Gemini Board)

First Jumper cable: Connect the first end to J2-2 (USB Tx) and the other end to J4-4 (ESP 32 Pass RX) this should direct the data from the Receiver

Second Jumper Cable: Connect the first end to J4-2 (Urb Rx) and the other end to J2-4 (ESP 32 Pass TX) this should direct the data from the Transmitter

You can check if you did these two steps correctly in the next section

Now that your jumpers are setup:

Go to the GitHub Page and clone the code from there onto Vscode or any other program where you can run code.

Go to UART_PORT = COM1 and change that to the COM of your Gemini board on the hardware manager

Again the bud rate should be right but if it turns out wrong you can go to the First Way and Find out the Bud Rate Yourself.

Then Save and Run the Code. You should end up with a list of timelines and numbers this is your raw data

Graphing the Data:

This step is very simple if your doing the python way and want to select a specific column just do alt and shift while hovering your mouse on the column you want to select

1- try select the time maybe the time in minutes for your x axis and copy those values

2- for your y axis you can have multiple variables but in order of this rssi1,rssi2,lq,snr,ant,rf_m,pwr,d_rss1,d_lq,d_snr

these represent what you should name your y-axis variables after depending on what column after the timeline column you choose so if you choose the first column of values that are not time then that should be name rssi1 when you graph it so its clear what numbers we are tracking and for what.

After you get your values for your x-axis and y-axis (maybe multiple different y-axis graphs). you can copy them onto excel and graph them there or use any other graphing software since all you have now is raw data which you can graph in anyway.

Try make graphs that can give insight into what our problems really are so maybe you wanna graph the rssi1 and rssi2 to see whether one or both of them aren't behaving the way we expect them to. Or maybe you wanna graph snr (signal to noise ratio) to debug or check for other problems you think might be on the antennas.

Example of a graph (credit to Derek):