x4mer
  • Member for 11 years, 2 months
  • Last seen more than a month ago
Serial control of 25 LEDs from a single pin
16 votes

Shift Register and I2C is good, but only if there are at least 2 pins free. I suggest Dallas 1-wire port extender DS2408 will be an optimal solution. Code for Dallas 1-wire device access is not so ...

View answer
Is there a way to preserve EEPROM contents in AVR Atmega when burning a new firmware to flash with avrdude?
Accepted answer
11 votes

Before reflashing any Atmel AVR MCU you need to erase it. Erase procedure by default clears FLASH, EEPROM and lock bits. There are 2 ways to solve your issue: Read EEPROM, erase all, program all ...

View answer
Increasing ADC resolution by supersampling on a successive approximation ADC
Accepted answer
8 votes

Atmel has very clear application note about increasing ADC resolution by oversampling with sources in C. Description in PDF is here, sources are on Atmel website.

View answer
Do I need to program a USB-Serial FTDI chip before using?
6 votes

You may need to program FTDI chip only in case you need some advanced functionality like flashing your Company Vendor ID and Device ID to make your particular custom device to respond only to your ...

View answer
Capacitor charging-like signal on SPI port's MOSI line
5 votes

Looks like your MOSI line is being Z-stated sometimes and weak pull-up on this line is charging it up. This is not cross line interference.

View answer
How to perform a synchronous output on the Arduino?
5 votes

Add these steps to your algorithm: 0. Prepare first bit of data ... 3. Use external interrupt on rising edge to output prepared bit and put next bit into your bit holder variable. Count outputted bits....

View answer
Obtaining 240V from 480V 3-phase
Accepted answer
4 votes

You might be having a High Leg Delta type of supply like on the picture Which might explain why you see 240V between the neutral and phases. Please recheck voltage again to make sure that this is ...

View answer
How can I find out which leads are +, - and video signal on this miniature camera?
Accepted answer
3 votes

Looking at the back of the camera (connector side): Positive - connected to the bottom side (anode) of the tube-looking diode just above the connector. This is a common practice to place diodes on ...

View answer
Help with my PCB connection. Seems reversed
2 votes

Both low voltage connectors on your schematic are marked with reverse polarity. Try to keep 220V traces on PCB as far as you can from low voltage side. I suggest turning relay 90 degrees CW. You don't ...

View answer
Using an arduino in below-freezing temperatures
2 votes

Take a look at this crazy Arduino experiment with liquid nitrogen http://3.14.by/en/read/arduino-liquid-nitrogen-overclocking Although this is not exactly what you asked for, nevertheless you could ...

View answer
Controlling 500 LEDs with PWM
2 votes

I suggest using Binary Angle Modulation technique described in this article http://www.artisticlicence.com/WebSiteMaster/App%20Notes/appnote011.pdf Or check ShiftPWM library http://www.elcojacobs.com/...

View answer
Optocoupler Issue - Not sure why it isn't working - help needed
1 votes

Is there any voltage on Inhibit signal on a Servo drive when opto-isolator is not connected ? If there is nothing there - your schematic ain't gonna work. This may be fixed by adding pull-up resistor ...

View answer
Arduino Hangs when Connected to 220V Supply
1 votes

Current pulse is induced when switching on the load which end up building potential on sensitive part of your schematic and your digital circuit tolerates it badly. You could have avoided it totally ...

View answer
Control toy car transmitter with Arduino Uno
Accepted answer
1 votes

First step: Check VCC level of this transmitter IC. If it is 5V then it is safe to connect power and ground of the transmitter board to power and ground of your Arduino. Just to power them together ...

View answer
Why isn't my SysTick_Handler() being called in my LPCxpresso C++ Project?
0 votes

I had exactly the same problem once. Yes it is C++ vs C difference. Looks like the maintainers of LPC support libraries did not care for C++ developers. Full answer is here Bug in Keil ARM compiler ...

View answer
How can I write an analog voltage on arduino?
0 votes

If you are ok with limiting LED number to 8, you may have much simpler solution utilizing serial in parallel out register. 74HC595 will do the trick without any need for digital-analog-led conversion. ...

View answer
Flow diagrams for embedded applications
0 votes

Sorry, but you can't show several separate workflows on one connected flow diagram. There rarely exists a general place from where control of mainloop is interrupted by external event (interrupt) -> ...

View answer