Timeline for Microcontroller circuit
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 12, 2016 at 12:45 | comment | added | fadedbee | i2c bi-directional level shifting can be done with just two FETs - one for data and one for clock. It's good for sub-MHz operation. (i2c is normally 400KHz.) | |
| Oct 19, 2014 at 22:59 | comment | added | Bruce Abbott | Digital logic gates switch between low and high at a particular threshold voltage, but for reliable operation a wider range is specified. For TTL it is 0.8V low and 2.0V high, for standard CMOS it is 0.3*Vcc and 0.7*Vcc (actual voltages depend on Vcc). The EK-LM4F120XL can safely be powered from 5V through the USB port or +VBUS pad, which is dropped down to 3.3V by the on-board regulator. If you were using a bare LM4F120 MCU then you would need to provide your own 3.3V regulated supply. | |
| Oct 19, 2014 at 21:34 | vote | accept | Rogan Josh | ||
| Oct 19, 2014 at 21:34 | comment | added | Rogan Josh | Are you saying the digital buffer chip treats Vcc as high and anything below a certain threshold as a low, then will output 0V? I tested the chip with a DC 1.5V Vcc and input DC 9V - and the output was as expected DC 1.5V.. My goal wasnt to have the MCU power any device, as I want to use the external DC battery-supply.. So in your opinion I am safe to use my voltage-regulator to drop my DC voltage from 9V to 5V to power all my devices - including the MCU? That is using the LM317 regulator and a divider as in my circuit diagram, excluding any buffers.. | |
| Oct 19, 2014 at 8:33 | history | answered | Bruce Abbott | CC BY-SA 3.0 |