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Switch from JTAG to SWD with bitbang sequence on STM32F103VB

I am trying to switch from JTAG to SWD without any external devices. Why? Because I would like to use the SWO pin to send a stream of logging information to another device. To accomplish this ...
Heneer's user avatar
  • 489
11 votes
1 answer
558 views

Home made passive tablet pen

I have an old wacom tablet at home, its really big and I'd like to use it but I've lost the pen for it. It uses pens with passive LC circuitry. The board creats an EM-field (I can see it on my ...
Flying Swissman's user avatar
9 votes
0 answers
425 views

How to understand a complex diode-resistor function generator circuit?

I'm reverse-engineering a CRT anti-pincushion circuit and it uses a complex diode-resistor circuit to approximate the function X-k×X×Y², where X and Y are the deflection voltages. My question is if ...
Ken Shirriff's user avatar
  • 2,834
8 votes
0 answers
253 views

Estimate base-spreading resistance from Gummel-Poon model

I'm attempting to calculate the base-spreading resistance of BJTs from manufacturer-provided SPICE models, which use the Gummel-Poon model. This Agilent publication (Internet Archive link here, if ...
MattHusz's user avatar
  • 1,053
8 votes
0 answers
2k views

Is JTAG faster than SWD for debugging on an STM32F with STLINK-V3SET programmer?

There is a new STLINK-V3SET programmer that someone dropped off on my desk today. It supports USB 2.0. My thinking is that if SWD is the bandwidth limiter in the signal chain then a new programmer isn'...
Voltage Spike's user avatar
  • 83.4k
7 votes
1 answer
277 views

Clock generator output off by a factor of sqrt(2)?

I'm using the Si5351A-B-GM clock generator with the NX5032GA-25.000M-LN-CD-1 (25 MHz, 8pF) crystal. The fragment of the schematic is shown below (the rest of the schematic omitted for clarity): ...
jbz's user avatar
  • 73
7 votes
0 answers
154 views

Extremely long net in Xilinx synthesized design labeled "async_path". What's it for?

I used Vivado to synthesize a small design for the Xilinx xc7k-160t-1. The design includes a fifo instantiated with Vivado's XPM macros which crosses clock domains from 100.8MHz to 200MHz. When I ...
John M's user avatar
  • 1,439
7 votes
0 answers
372 views

x86 Motherboard Bring Up - Intel Tiger Lake UP3 CPU

For those who has experience with Intel x86 motherboard design and bring up. I'm in the middle of motherboard bring-up that has Intel Tiger Lake UP3 CPU. Seems like I had a good run so far at power-up ...
Firas Abd El Gani's user avatar
7 votes
2 answers
1k views

How to meaningfully compare Xilinx MCS files?

Brief I have two different boards with Xilinx designs that might be the same design. I am trying to compare the different MCS files to see if the designs in them are in fact the same design. Can this ...
Mr. Snrub's user avatar
  • 2,593
7 votes
1 answer
895 views

Modeling scalar control of PMSM

I have met with a scalar control algorithm for a permanent magnet synchronous motor. I haven´t heard about it before so I decided to develop a dynamic model to further analyze this control algorithm. ...
Steve's user avatar
  • 1,103
7 votes
2 answers
264 views

Phase shift near saturation mitigation in input stage amplifier -- How does this work, why does this work?

I'm trying to understand how this circuit works on the input stage to the 4192A Impedance Analyzer. Apologies for the quality... this is the best scan I could find. The design is furnished with the ...
Evan's user avatar
  • 359
7 votes
1 answer
5k views

STM32F0xx UID decoding

In my project, I need to make readable 96-bit UID. In STM32F0xx reference manual RM0091 section 33.1 Unique device ID register, it is described how the number is encoded: ...
vlk's user avatar
  • 458
6 votes
0 answers
144 views

Vivante video memory size?

I'm using an NXP i.MX 8MP, with Vivante GC7000UL and GC520L GPUs. Using the Etnaviv open source drivers. For the life of me, I can't figure out how much video memory is made available to the GPUs, nor ...
jaskij's user avatar
  • 1,233
6 votes
0 answers
194 views

Identify kind of cable with markings such as "WE-B 2 PAIR" on the jacket

While cleaning out our back yard shed, I came across a coil of cable of a kind that I have never seen before (image below). It was left here by the previous home owner, who worked in some kind of ...
Bill Norman's user avatar
6 votes
0 answers
1k views

So can we just draw 500 mA from any USB port without enumeration now?

The USB Type-C Spec R2.0 defines the USB Type-C Current feature, in which the power Sink observes the voltage on the CC pin to determine how much current is available from the Source, which falls into ...
endolith's user avatar
  • 28.8k
6 votes
0 answers
190 views

Frequency locking for averaging resampling

Background I've done a long one-shot measurement of a periodic signal by an oscilloscope. Thus, I've captured around 250 periods of a signal. The signal itself is a pseudo-random binary sequence at ...
skobls's user avatar
  • 67
6 votes
1 answer
1k views

IIP2 Second Order Intercept Rule of Thumb

I'm faced with the problem of explaining the harmonic production in a system where the second order intercept points of the cascaded components are unknown. As a way to bolster my explanation, I would ...
Jim's user avatar
  • 403
6 votes
0 answers
765 views

Understanding EGSM-900 (LTE 8 band) electromagnetic spectrum

I am trying to fully understand the physical layer of the GSM standard. For doing that I am looking at the E-GSM-900 band (mostly used in Europe). In my country these frequencies has been assigned to ...
JVGD's user avatar
  • 185
6 votes
0 answers
1k views

How to protect single cell Ni-MH battery (overcurrent, undervoltage, overtemperature, etc.) during discharge?

Story I am designing a boost converter for a battery powered board. I am planning to use single Ni-MH battery. The needed output voltage is 3V3. The device will be in deep sleep mode (drawing few ...
ayazar's user avatar
  • 351
6 votes
1 answer
7k views

RGBHV (VGA) to YPbPr Converter and Waveforms?

Purely for hobby, I am working on an RGBHV (VGA) to YPbPr (Component) converter circuit for old games consoles modified to output RGBHV on a VGA cable. From the game consoles, the RGB signal is taken ...
Lt.Derpington's user avatar
6 votes
1 answer
6k views

Run IAR Program without Debugging

I'm having a simple problem with IAR Embedded Workbench, programming an STM32 using an ST-LINK/V2 programmer. I'm trying to run a program that temporarily switches off the JTAG pins, so I can't run it ...
Reiik's user avatar
  • 81
6 votes
1 answer
591 views

Charge mode piezoelectric signal conditioning

I have a charge-mode piezoelectric dynamic pressure sensor (datasheet link) that I want to read a signal from. If you look at the datasheet it says the sensor outputs are in a balanced and floating ...
Ryan Helminen's user avatar
5 votes
0 answers
109 views

Why does output of this reverse bias noise source not have normal distribution?

I am trying to build a noise source based on reverse biased PN junction (i am trying to replicate this project https://altusmetrum.org/ChaosKey/ ). At this point i tried multiple iterations but so far ...
pigster's user avatar
  • 51
5 votes
0 answers
329 views

How to match an edge launch SMA connector to a pcb with coplanar waveguide with ground?

I'm trying to develop a pcb that is capable of handling signals over 6GHz and created a test board to see how the pcb and connectors perform. The pcb is a relatively low-cost 4-layer FR-4 TG155 board ...
fivejeez's user avatar
  • 123
5 votes
0 answers
95 views

Circuit with resistance equal to input resistance

I want to use a digital potentiometer, however, the digital potentiometer has a power limit, which means I can't apply the voltage for my application. I am looking for a circuit which functions as an &...
Eduardo Ramírez Gómez's user avatar
5 votes
1 answer
1k views

Is my understanding of DRAM memory array topology in relation to "rows" and "columns" correct?

Assume a x16 DDR SDRAM module with 2b banks, which are made of 2r rows, which are further composed of 2c columns, where each column is 2w bits "tall". Assume that the interface is burst-...
jayded-bee's user avatar
5 votes
1 answer
456 views

Help identifying Hall sensor (95B2h)

I am trying to identify a Hall-sensor located on a keyboard. There is one of these sensors underneath every key. One of them are broken and needs replacing. However, I cannot identify the component. ...
wronex's user avatar
  • 161
5 votes
0 answers
309 views

Bidirectional flyback converter design

I see a fair amount of questions on here about designing flyback converters, but I don't see any about designing a bidirectional DC/DC flyback converter, such that either side can be the primary and ...
orangeandblack5's user avatar
5 votes
1 answer
97 views

Do I need a clock crossing circuit for signals clocked by mirrored PLLs?

Assume that within an FPGA, I have two data streams that are being driven by two clocks. The two clocks are generated by 2 physically separated PLLs (still within the same FPGA), both of which have ...
Sittin Hawk's user avatar
5 votes
0 answers
2k views

STM32 - I²C Slave HAL Callback ACK

Objective: implement a single byte I²C slave on STM32. Materials: STM32L452RE Nucleo-64 board, HAL Library, CH341 USB-I²C adapter(1), Artix Linux with Runit, Rhode & Schwarz RTB2004 oscilloscope ...
tweak's user avatar
  • 51
5 votes
0 answers
935 views

Custom RP2040 PCB Not Detected by PC

I designed a custom RP2040 to control some 24V LED strips. The official hardware design guide from the Raspberry Pi Foundation is what I followed for my design. It was then sent out to JLCPCB for the ...
Agriculex's user avatar
  • 495
5 votes
1 answer
297 views

Breaking capacity for fuses at mains inlet

Is there any official guidance as to what the breaking capacity should be for a mains inlet fuse? Assuming the appliance is intended to be fed from a normal domestic socket. I understand that in an ...
Peter Green's user avatar
  • 22.5k
5 votes
1 answer
124 views

Is LTC2485 Arduino library missing information?

I'm using LTC2485 and got confused by the provided software code vs. the datasheet. As described in LTC2485 I2C Data Format the LTC2485 ADC is 24 bits + sign ADC so like 25 bits. In the given software ...
ThomLB's user avatar
  • 51
5 votes
0 answers
6k views

How important really is the impedance of an USB 2.0 signal line?

The USB 2.0 specs requires a differential impedance of 90 Ohms and a common mode impedance of 30 Ohms (with some tolerance). This, by definition, gives a target of an odd mode impedance of 45 Ohms and ...
Lorenzo Marcantonio's user avatar
5 votes
0 answers
1k views

What is the upper frequency limit for an op-amp integrator?

I'm designing a circuit to process a di/dt signal. As the input is the differential of the measured current, I have to integrate the voltage to provide a representation of the current. The duration of ...
Sylvia's user avatar
  • 51
5 votes
0 answers
257 views

Cannot find what causes faults on DRV8353RH

I keep getting faults on a a new batch of ESC boards based on the TI DRV8353RH & Infineon IPT020N10N3ATMA1. Please consider: When starting a motor at 48V - 56V the DRV asserts a fault after ...
Alex Er's user avatar
  • 111
5 votes
2 answers
140 views

automatic submersible pump actuation project

I have a project for automatic submersible pump actuation using a microcontroller. I've done for two voltages like 5 V and 12 V and its corresponding relay. Also, in each board there is a transistor ...
Anil Suha's user avatar
  • 101
5 votes
0 answers
220 views

Invisible magic components that spoil the Eagle preview

You know, after the eagle board design is finished, you can see the card on the preview screen. I'll show you two examples. There is no problem with one. The card is centered on the preview screen. ...
OmerFaruk's user avatar
5 votes
0 answers
271 views

Detection of CT secondary subsidence current

In utility power system protection we have a protection function called "breaker failure" protection. This protection is used to take appropriate action if/when a circuit breaker fails to ...
relayman357's user avatar
  • 3,497
5 votes
0 answers
578 views

Drift with Madgwick algorithm with fast movements

I am trying to correctly track orientation of a sensor with accelerometer and gyroscope using the open source Madgwick algorithm. The algorithm returns quaternions which represent the rotation between ...
tristan's user avatar
  • 51
5 votes
0 answers
95 views

What complications arise when designing a USB device sharing switch?

I wish to design and build a USB switch capable of transferring one USB keyboard between one of two computers. I wish to automate the process of unplugging the device from host A and plugging it ...
MrArsGravis's user avatar
5 votes
0 answers
175 views

Potential issues with mounting tiny PCB directly to piezo transducer?

I am designing a very small signal conditioning daughterboard with the intent of mounting it directly underneath a cylindrical piezoelectric force device/"sensor" to rectify and filter the ...
Matt's user avatar
  • 201
5 votes
0 answers
274 views

SD card SPI initialization Check Pattern Fail

I'm trying to interface a Swissbit 512MB (S-450u Series) SD card (datasheet here) with an ARM microcontroller through the card's SPI interface. The datasheet for this card says it's fully compliant ...
Carlos's user avatar
  • 61
5 votes
1 answer
304 views

RFID reader array using row/column RF switches (multiplexers)

I need an 8x8 grid of RFID readers arranged on an 8"x8" board. The RFID tags will be placed only millimeters above each antenna. I was wondering if I could use one 1:8 RF switch (e.g. pSemi PE426482) ...
Hamid's user avatar
  • 75
5 votes
0 answers
313 views

ATTiny85 clock speed problem

Using an ATTiny85 and an Arduino loader I created a simple device for turning on an exhaust fan based on a light sensor. The ATTiny85 turns on the fan after activating a warning light and sounding an ...
ArcZap's user avatar
  • 51
5 votes
0 answers
146 views

What is the relation between resonance frequency and piezoelectric charge coefficient?

We know that the maximum power is lost at the resonant frequency,where the impedance is minimal. On the other hand, when the impedance is minimized, the charge coefficient is maximized. In resonance ...
Fa Had's user avatar
  • 59
5 votes
0 answers
145 views

Differentiator circuit sees noise on PCB after 2 min

I'm new to PCB design, and looking for some advice. I designed a PCB shield and I'm seeing a lot of noise in my differentiator circuit. The circuit will run perfectly for about 2 min and then all of ...
Connor Herron's user avatar
5 votes
0 answers
850 views

PIN Photodiode gamma detection amplifier circuit - rectangular wave output

I've been working on a project recently, where I need to build a device which detects gamma radiation and can be used for gamma spectroscopy. I've done some research and found many interesting ways of ...
maseeoo's user avatar
  • 53
5 votes
0 answers
255 views

Strange I2C communication

I am currently trying to test the SHT3x series humidity sensors by Senserion. I have their EK-H4 evaluation kit to get data from the sensors. I can plug in the sesnsors provided with the kit, and all ...
MCG's user avatar
  • 12k
5 votes
0 answers
2k views

Altium Designer: Copy room format does not modify polygon net name

I have a multichannel PCB with channels named U1, U2 and U3. I'm trying to copy the format of one channel to other two: component placement, routing, polygons. In the first place I was facing that ...
Roman Matveev's user avatar

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