19

You could use a SIP switch instead of a DIP. The saving in board area would give you the space for your I2C interface (or a simpler interface like a shift register with input latch): The picture shows it horizontal but it actually mounts vertically.


11

Each PCI device (when I write PCI, I refer to PCI 3.0, as opposed to PCIe) has two "ranges" - configuration range (CFG) and "memory mapped input-output" range (MMIO). I won't deep dive into the concepts of address spaces and MMIO because it will make the answer too long and complicated. Google them if they are not familiar to you. In short: CFG range is a ...


9

"DIP" switch First of all, a "DIP"-switch doesn't have to be large. Here is a 6-bit SMD switch with J-hook pins and a 1.27 mm pitch: Potentiometer If you're desperate reducing the footprint, and you can inconvenience the user a bit, you could use a potentiometer connected to an A/D converter. Since you need 64 settings, a 12-bit converter should have more ...


9

Do you have a spare ADC? If you have a spare 8-bit ADC on a nearby microcontroller, you could probably ditch the IO expander in favour a resistor network - either a R-2R ladder or a binary weighted ladder. That would encode the switch positions as an analog level. Resistor ladders are available in very small packages, but I don't know if you'll get one ...


9

The diagram is really confusing. In the 4-wire connection below on the right, for resistance measurement, the "force" wires are the ones (with red arrows) providing the current for the resistor under test. Through the "sense" wires only the current required by the voltmeter is circulating, causing a much lower drop. In this example both current and voltage ...


7

CCSv5 has a graphical memory use display. Select View -> Other -> Code Composer Studio -> Memory Allocation. The first time I used this, it needed to set up some configuration for the project .... but it prompted for everything and was relatively simple.


7

One or more Coded rotary switches are what you're looking for. Theoretically jumpers offer more configurations when you're requiring 100s of options because users can short any number of them together in different configurations, add resistors, capacitors, diodes, etc. but that is very technical for users and for the board to decipher!


6

The FPGA configuration itself is stored in SRAM (i.e. flip-flops). A newly started FPGA has an empty configuration where typically all pins are in a somewhat idle state (e.g. weak pull-up), and clocks are not forwarded inside the FPGA, so no activity takes place. From that state, either the FPGA boots actively by accessing an external device (usually, flash ...


6

To get the detailed info including register map and other register details for an ST microcontroller, you want what they call the reference manual, not the datasheet or the user manual. See for example: Reference manual for STM32F405/415, STM32F407/417, STM32F427/437 and STM32F429/439 lines Reference manual for STM32F0x1/STM32F0x2/STM32F0x8 lines ...


6

I found the answer elsewhere but I will repeat it here for other people: Close Atollic TrueStudio (not sure if this is needed) Startup ST Utility Press the Reset button and keep it pressed Select Erase Chip (in Target menu) Release the Reset button The chip is erased Close ST Utility Startup Atollic TrueStudio Debug should work now


5

"Earth" or "ground" in this case just means the point in the circuit the designer decided to call "zero volts", and use as a reference when measuring voltages elsewhere in the circuit - it does not imply an actual connection to the earth. I'd prefer to call that point "circuit ground", or "common", rather than "earth". The important thing to notice in a ...


5

It's not really possible for the FPGA to exit the start up routine with a corrupted configuration as it confirms the CRC of the configuration after the complete configuration is loaded, but before it tries to start up. If it does not match, then the DONE pin stays low and you can check on what happened by reading the status bits over JTAG. Since it seems ...


5

There's an easy way to force windows to drop anything on that port and that's to rename/reassign it. I've done it myself when the serial gets abruptly disconnected and windows doesn't handle it. To do this you need to: 1) Go to Control Panel-> Device Manager 2) Look for the COM port and right click, go to properties. 3) In the Advanced tab there is a ...


5

NXP doesn't seem to provide this, but STM32F4 user manual (page 270) shows a block diagram of a typical GPIO pin. As you can see, the pins are connected to all blocks: Analog/Digital Input as well as the Output sections. The control registers enable/disable and configure these blocks so they don't interfere with each other. There are also separate enable ...


5

I couldn't find the specific internal schematic for NXP's part in the User Manual, so I will explain using the one found in a ATMEL ATMega328, but they should look similar. The picture shows the internal schematic for a single pin. The highlight part is the port direction pin part. When The port is set to output (via the databus, where one can set each pin ...


5

Is there anyway that I can somehow connect this to my computer so that every time I click the button, it sends the signal of the enter key on my keyboard? Preferentially something that uses usb to reconfigure the signal. Yes you can do both. Find a secondhand USB keyboard. This shouldn't cost you anything. Open it up and removed the keyboard controller PCB....


5

I might surmise that the "force" and "sense" words in the picture make reference to the "source and measurement" properties of the SMU. Correct. Each SMU can output a "force" signal (the excitation signal), and it can measure ("sense") the effects of that signal upon the device under test (DUT). Moreover, why do we have a variable battery? The variable ...


5

Been searching the internet top to toe for an answer too, I think the best I could come up with alongside the H bridge was this Vishay resistor network ic. The naming on the datasheet doesn’t line up at all so not convinced I’m correct, but just thought I’d share.


4

From some Googling this seems like a commonly produced module based around the CA-5461BS chip. It might have many manufacturers like the HD44780-based LCD module. To summarise it's behaviour, it consists of four separate digits with a separate anode per digit and shared cathodes for each digit. See page 3 of the PDF.


4

The best way to look at the issue is that the VCO (Voltage controller Oscillator) can be very sensitive to voltage ripple and spikes which translates directly into jitter. the key to a good PLL is low output jitter, but there is a a compromise, a low jitter PLL will also be slow to lock. So contrary to what Andy has to say, you must run the PLL at as high ...


4

Yes, a better way of defining peripheral clock would be: #define GetSystemClock() (80000000ul) #define GetInstructionClock() (GetSystemClock()) #define GetPeripheralClock() (GetSystemClock()/(1<<OSCCONbits.PBDIV))


4

I see no difference in the pin outs at all: - TI's offering in red box; ONsemi to the right and lower Why do the manufacturers don't follow a logic layout (e.g. PIN 1 = INPUT and 3 = OUTPUT like all(!) LM7805) Generally they don't and, unless I'm being really stupid they don't for the LP2950.


4

NFC NTAG from NXP + smartphone. It is basically an I2C EEPROM, that can also be read and written over NFC without system power.


4

I cant comment as I don't have enough points, so I will submit this as an answer: closest I could find. It is an IC made by Vishay with the correct package (SOIC-24(W)) as far as I can guess. And I only found it by using different search terms with some terms between hyphens. I guess this could be the correct IC, as the one I found is an H-bridge driver, so ...


3

Answer based purely on the information provided in the Reference Manual. Contacting Microchip tech support would probably be a good idea. Q1: Can BWP bit be reset? No, since the configuration bits are stored in the BFM, which is write-protected. From the PIC32MX Reference manual, Section 32.2.1: In the PIC32 device families, the Configuration Words ...


3

Like most FPGA development boards, you can restore the factory shipped configuration by following the same steps you use to load your own firmware, except that the configuration bitstream is ready-made and does not need to be recompiled. So instead of opening and building a project, you instead just go straight into the programming tool. (If this were Xilinx ...


3

It's a bug. The peripheral clock should be equal to the system clock if you set FPBDIV = DIV_1. So it should be: #define GetPeripheralClock() (SYS_CLOCK)


3

What you're talking about is called sample-and-hold. To do this, you need a storage element - a circuit without one like yours will rapidly drift. The most common way to do this is to use an Op-amp: The two triangles represent op-amps configured as voltage followers. The first one acts to decrease the impedance of the input, allowing the capacitor to be ...


3

It is a bug in XC8. As a workaround you can edit 18f14k50.cfgdata in C:\Program Files (x86)\Microchip\xc8\v1.01\dat\cfgdata\. Just above line with CWORD:300005:88:88:CONFIG3H add new line CWORD:300004:00:00:CONFIG3L. Full post at http://www.jmedved.com/2012/08/elusive-config3h-setting/.


Only top voted, non community-wiki answers of a minimum length are eligible