Bring Up Plan

This is our board bring-up plan as submitted for Milestone 8

General Plan:

• Constructing the board efficiently requires doing as much as possible before it arrives, and then having a good plan for after it arrives. Then, before putting our board to use, it is a good idea to make sure all the components are the correct values specified, soldered in place properly, and to make the ground side of anything polarized, such as polarized capacitors, are connected to ground. We need to be prepared to deal with components that get damaged or lost. Therefore, we need to have extra components if we run into that situation. it is also important to verify that the software for the Quisk and Arduino works. If the software is failing to work, debugging will be needed. Finally, we can start getting the SDR to do what it is intended for: working on software to receive specific radio signals to listen to.

Before the PCB arrives:

• Before the PCB arrives, it would be a good idea to make progress on any tasks that could be completed. This includes using a KiCad plugin to generate a bill of materials (BOM) and order parts, which should be completed by the time this plan is turned in. Additionally, we can get to work on the getting the coils for our bandpass filter set up. For our bandpass filter, we have three coils: two are 1.3 uH (these are L1 and L3), and the last (L3) is 150 nH. L1 and L3 will have T50-6 cores, and they will each need 18 turns for 1.3 uH. L3 will have a T37-6 core and will need 7 turns for 150 nH. Additionally, some software setup can be done beforehand. At the moment, the SDR software, Quisk, has been loaded up and we have confirmed it works with the soundcard. We should load the Arduino code when possible. Some of the testing will need to be done with software, so researching some ways to test certain aspects should be done beforehand incase any test software needs to be made, which likely will need to happen. Also, the current software needs to be modified to use the new oscillator scheme.

Board & Components:

• Once the PCB arrives, the goal is to construct two boards as quickly and carefully as possible. First, we need to make a checklist for all the components we need to make it easier to find them and to keep track of what we have soldered on. This naturally comes with a Bill of Materials (BOM). Finally, when we have all our components, we will need to separate them by component type and intended circuit stage (Example: Capacitor, 1.1 nF, for BPF). Good organization should prevent simple component placement mistakes.
• Next, we will place the components on the board and solder them. For organization, it is a good idea to place all parts for one particular stage first. Also, it is good practice to solder the surface mount parts first since they are smaller. As components are soldered on, we will try to question everything, and compare our boards to ensure that the proper work is being done. A misplaced component such as a surface mount resistor can be easy to miss, but it is crucial that nothing is placed incorrectly. Then when everything is soldered, going over it with a microscope will help ensure that any bridging or cold solder joints will be discovered and hopefully fixed. It is possible that such errors might become apparent during testing, but just carefully going over the board is the best way to find such errors. Also, if the two of us are working on the board, having each of us check each other’s work will make the chance that any misplaced parts or poor solder jobs are discovered significantly higher. After soldering everything together, it is time to test the board. When testing, we must focus on one stage before moving on to another. This will make it easier to debug any possible problems we may encounter. Before using the antenna, a signal generator will be used for testing. And before testing the bandpass filter, jumpers should be utilized so a problem with it is guaranteed to not spiral into issues all over the board. It would be a good idea to make sure that 5V is in fact worse than 4.3V. Ground loop noise can be checked for our different possible setups, such as how it changes when using the antenna or signal generator, or when it is hooked up to different computers, etc. A USB meter can be used to monitor the current when it is plugged in, and the IR camera is useful for determining why too much current may end up being drawn. Some additional testing that will need to be done includes testing the bandpass filter to be sure the frequency range is what we intended to pass, and then testing the mixer to make sure the I and Q signals are both being properly utilized.
• Before checking that everything is working together, we will try to make sure that we have not missed any tests that could mean the difference between an operational SDR and a lot more work to get to an operational board. Ideally, sufficient testing will mean that when everything is able to be tested together, it works as expected without any additional head scratching to determine where issues may have been overlooked.

Debugging:

• If problems arise, we must first determine what they are. Is it noise, a component oriented incorrectly, soldering errors, wrong component values, ground loops, or short circuits? Once we find out what the problem is, we need to figure out what is causing the problem and fix it. For example, if there is a short circuit, we should inspect the solder joints first because this is commonly caused by solder bridges where the solder on one joint is touching another joint. These can usually be fixed by simply running a soldering iron tip through the bridge if it is one a through-hole component or a surface mount component if it is large enough. Once all the problems are taken care of if there are any at all, then we can finally start having some fun using our radio as a radio. Before we do, we must verify that the software for the Arduino and the soundcard is working. If not, debug the program for the Arduino or the application for the Quisk. Realistically, though this plan considers many scenarios, it is not unlikely that some may have gone overlooked, so the overall plan is to be ready to deviate from the plan if needed. However, once all that is done, let the radio listening begin.