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NESI Hardware Questions

Is a typical laptop able to provide 5 volts to the NESI board?
Yes, a typical laptop provides the necessary power requirements for the NESI Board to function properly.

Can I power the NESI Board from an external power supply such as a 6V or 12V battery?
You can power the NESI board with an external power supply up to of 6 or 12 volts. If you plan to do this then you need to have a voltage regulator to step the voltage down to 5 volts. The NESI Board needs to have a 5 volt supply through the USB port or some of the internal circuitry will be destroyed. The voltage regulator also serves to create a steady voltage that isn't dropping with time.

Is there a specific orientation for the camera? Or can we have it either way?
Yes, there is a specific orientation for the camera and the white outline on the NESI board highlights that for you. The pickets have a specific orientation and the placement of the camera is that which it will be closest to the center of the board.

Why are my UART ports not working when they are connected to the camera port?
For the UART connection on the camera port, the schematic shows power, TX, RX, and ground. The TX and the RX pins are where you connect your RX and TX from your peripheral in that respective order.

NESI Software Questions

I have little to no experience programming, and don't understand how to write code. Where should I go?
The first thing you should do is go to the Getting Started page of the nesiwiki and follow the instructions to install the software development environment, MPLAB X and the XC16 compiler. You will use this integrated development environment to write code in the C programming language. There is already a fairly wide user base for C programming, an example of a very popular open-source microcontroller is Arduino. Because of this, one can use the Arduino tutorials in order to learn about programming. After learning the basics and viewing the NESI software videos and information on the NESI Software and Example Project pages, one can almost immediately begin laying out their code. You can also look at individual commands and structures on the Reference page The main part to look at is Control Structures, which will be how you arrange your code so it follows the same path as your programming flowchart. There is one major point to note when transitioning from Arduino to MPLAB X, and that is that what Arduino calls "setup" and "loop" are both functions. functions have a name, followed by two parenthesis () and then curly brackets, which hold the actual code. In the NESI Software, much like arduino, most of your commands are actually functions, which use arguments attached by a period [ button.getStroke() ]. This is a special feature implemented into the NESI Software to resemble coding in java. Since these functions have already been defined elsewhere in the project, you do not need curly brackets when calling these functions e.g. button.getStroke().
-Submitted by: Jackson Hole High School

Can I do PWM control of the Power Driver A or Power Driver B ports?
The Power Driver A and Power Driver B ports are unable to be configured as a PWM signal. Please see the PWM motor control question of the NESI Peripherals section for more information.

Can we have the SD cards store data at the same time the laptop displays at real time?
Unfortunately, you are not able to display the changes in data in real time. When you connect the NESI Board, Windows scans and saves a copy of the material. Normally a system containing the data will not be updating itself while plugged in so the computer will not be checking for updates in the information. When you safely remove your hardware from the computer it saves the data which will then be recognized when Windows rescans the card (i.e. when plugged back into the computer).

I am missing some system library files, i.e. I get errors when we include system.h and string.h and our datetime function isn't working.
The first thing to do is make sure the source files created by the NESI development team are included in your designated project directory. Next, you may want to uninstall and reinstall MPLAB X because and internal error may have occurred. At this time it is a wise choice to make sure you have the most up to date version of MPLAB X and compiler.
-Submitted by: Tri-County High School

Peripherals Questions

Can I control a device that uses more than 5V or 6V using the NESI Board?
The simple answer is yes, but not always. What you can do is use an external power source to power the device that require a larger voltage; once the device is powered you can control the device and or receive data through the microcontroller pins. If you are part of NASA HUNCH and intend to take your experiment to the International Space Station external batteries are not permitted. You can also design an external circuit to step up the voltage depending on circumstances.

What SD card should I use?
If you are using only 1 uSD card then you can use any off-the-shelf uSD card. Mouser electronics has a variety of sizes at cheap prices. If however, you intend to use two uSD cards then you must order industrial grade SD cards, such as those offered at DigiKey. The industrial grade SD cards are the only ones proven to work with the NESI Board because they come with the chip select feature. Please note that the industrial grade SD cards are significantly more expensive.
-Submitted by: Tri-County High School

I want to control a motor using PWM. How should I do that?
To power high current devices such as motors, you need to hook them up to a power driver. There are 6 power drivers on the NESI Board that can be adapted for the use of a motor. Only 2 of these power drivers, the ones controlling the LED's, have the ability to be controlled with a PWM signal.

Case 1) If you are NOT using LED's in your experiment then you can use one of the LED power drivers to control your motor. To do this, remove the current limiting resistor (R11 for the B LED bank and R12 for the R LED bank) and replace this with a short. Next, take the positive lead of your motor and solder it into the one of the positive LED holes and take the negative lead and solder into the cathode side (the cathode side has the thicker white band around the LED hole). To then control your motors speed you use the dutycyle function that is created in the LED source file.

Case 2) If you are using both sets of LED's the only way to control your motor is by attaching it to power driver A or B and writing a software routine to create a PWM.

Miscellaneous Questions

Do you have a CAD model of the NESI board so we can use it in our CAD assembly model ?
A 3D model of the board does not exist at this point in time. You will have to use some calipers to get exact dimensions to create your own model. If you do create a 3D detailed model of the nesi board please send a copy of the file to nesidev@gmail.com so we can provide this to the next team that would need this.
-Submitted by: Tri-County High School
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