Where should I start if I want to implement a isolating dc to dc converter for biotech circuits like a EMG power from a USB to protect against MAINS accidents?
reddit.comu/Objective-Local7164 — 2 days ago
u/Objective-Local7164
r/rfelectronics r/AskElectronics r/shittyaskelectronics r/3DPrintingCirclejerk r/embedded r/ElectricalEngineering r/PowerElectronics r/3dprinter r/smartwatch r/PCB
Playing around with inductors, transformers and saturation.
Stumbled across a interesting phenomenon that I want to share with you all. Because the inductor wants to keep the current flowing, when the polarity of the AC Voltage source swings negative, the inductor fights against it to prevent current from flowing in reverse.
u/Objective-Local7164 — 3 days ago
▲ 14 r/embedded
Gpio says it has a 20 ma current sink limit. does the internals of the gpio limit the current itself or do I need to add a current limiting resistor between my voltage source and the gpio pin to make sure doesn't go over 20 ma
reddit.comu/Objective-Local7164 — 7 days ago
▲ 15 r/embedded
Im a little bit confused about JTAG. Im trying to buy my first jtag and im seeing a bunch of stuff that is a swd to jtag converter type of module. Can someone please explain this to me.
I would greatly appreciate any cheap jtag programmer recommendations. Thanks.
u/Objective-Local7164 — 7 days ago
Does Bias Shield Drive create a significant difference in biosignal aquisition?
I am almost done with my ADS1299 design and there is an option for a bias shield drive op amp and I am trying to find info online showing the effects of it but I cant find anything I would love to hear from anyone with experience with this. Thanks.
u/Objective-Local7164 — 9 days ago
▲ 6 r/AskElectronics
Thoughts on Tin vs Gold pin header?
I read that tin solders a lot easier, would this overcompensate for golds higher conductive properties?
u/Objective-Local7164 — 13 days ago
▲ 5 r/embedded
Which nrf54 chip do you guys like the best and why?
I will be getting a DK board for one of the chips and doing some serious deep diving into whatever chip I end up choosing and will be using it for multiple projects. Personal experiences and opinions would be greatly appreciated, thanks.
u/Objective-Local7164 — 17 days ago
Is this the right right way to calculate LED current?
So I take 3.3V - 3VF (led drop) and get 300mV. Then I take that and do i = V/R? to get 30ma = 300mV/10ohms? I am suprised that the voltage drop of the diode is completely subtracted out when doing ohms law. Is this correct? and also is the forward current spec of the led the current at which the leds forward voltage drop will be at its full 3V?
u/Objective-Local7164 — 21 days ago
▲ 3 r/AskElectronics
Is this how a diode works?
My custom falstad diode settings.
The datasheet for my LCD backlight diode properties
Should I be adjusting R to limit the current to 15-20ma? is that what the schematic is suggesting?
When calculating R is the equation 3.3V - 3VF = 300mV 300mV/10ohms = 30 ma? Is that how you actually calculate the current that will be in the circuit because this is kind of confusing me how the diode VF drop is just subtracted from the V in i = v/r. I see it says 15-20ma so that would mean i would want to use a 20 ohms resistor?
LCD datasheet
u/Objective-Local7164 — 21 days ago
I have never connected 2 seperate boards powered by different supplies, any advice and gotchas I should be aware of?
u/Objective-Local7164 — 24 days ago
▲ 12 r/embedded
What is the cheapest way to flash a nRF52840 without paying $500+ for a segger jlink?
reddit.comu/Objective-Local7164 — 25 days ago
Can I program a NRF52840 for the first time with a USB to UART TTL module?
I was doing some research and cannot come to a conclusion. When I flash this chip for the first time on my pcb can I do it with the USB to UART through any UART capable i/o pins or do I need to do something else first?
There are SWDIO AND SWCLK pins also that might be important for initial programming but I dont know
u/Objective-Local7164 — 25 days ago
▲ 1 r/AskElectronics
Can I program a NRF52840 for the first time with a USB to UART TTL module?
I was doing some research and cannot come to a conclusion. When I flash this chip for the first time on my pcb can I do it with the USB to UART through any UART capable i/o pins or do I need to do something else first?
There are SWDIO AND SWCLK pins also that might be important for initial programming but I dont know
u/Objective-Local7164 — 25 days ago
Is this how i2C works?
MASTER = STM32WB15CC
SLAVE = MAX30101
From start to finish
the stm32 initiates a start condition by pulling sda low.
the stm32 then writes the slave id on the sda line followed by write condition.
the MAX acknowledges.
the stm32 says what MAX register it wants to read from.
the MAX acknowledges.
the stm32 sends a repeated start condition and calls the MAX address again then sends a read signal.
the MAX acknowledges and begins outputting the bytes in the register onto the sda line and the STM32 acknowledges after each byte is sent and repeats.
is this correct? also, if the NACK and P (stop condition werent sent at the end and instead a stm32 acknowledge was sent followed by a 4th,5th,6th, bytes were sent by MAX would the data communication of bytes continue indefinently without the need to resend the register address and slave address all over again?
u/Objective-Local7164 — 27 days ago
▲ 3 r/AskElectronics
I found GPIO pin alternate functions, but I cant find anything anything about what the GPIO's can generally do besides that.
In the diagram it looks like all GPIO's are connected throgh the AHB line to all the i2c, spi, usart, dbg... blocks of the mcu but why would USART1 for example be an alternate function on only a specific few i/o's? Can someone please help me understand this
u/Objective-Local7164 — 28 days ago
so pretty much any typical reverse current leakage through a diode will create a voltage close to the voltage source on the drain of an off FET because its basically infinite impedance?
u/Objective-Local7164 — 1 month ago
Do I connect these side pieces to ground or just a un connected copper pad?
This is for a ZIF connector for a LCD screen DATASHEET
u/Objective-Local7164 — 1 month ago
▲ 1 r/AskElectronics
Do I connect these side pieces to ground or just a un connected copper pad?
This is for a ZIF connector for a LCD screen
u/Objective-Local7164 — 1 month ago
When the USB is plugged in wouldnt the current also return into the negative terminal of the battery?
The 5V USB and the 3.6V li-ion battery share the same ground plane. Wouldnt the return current of the USB also go into the negative terminal of the battery if they are both connected to the same ground plane?
u/Objective-Local7164 — 1 month ago
▲ 4 r/AskElectronics
This is saying that the Rdson will be about 1.2mOhms at 3.5V Vgs right?
I just want to make sure before I incorporate this into my design.
u/Objective-Local7164 — 2 months ago